FUNDUS PHOTOGRAPHY                                    
                                                                                
                                                                                
     A photograph of the ocular fundus of one eye was taken on examinees aged   
     40 years and over by a trained examiner in the mobile examination center   
     (MEC).  The protocol for this component did not detail any medical,        
     safety or other exclusions.  However, if the designated eye was            
     unavailable due to an extremely small pupil, severe corneal or lens        
     opacity, complete retinal detachment, or other reason, the other eye was   
     photographed.  If both eyes were unavailable, no photograph was taken.     
                                                                                
     Because the component was administered in the examination center, MEC      
     examination weights (WTPFEX6) should be used for data analysis.  For       
     more information on the use of sample weights in the analysis of           
     NHANES III data, refer to the NHANES III Analytic and Reporting            
     Guidelines (U.S. DHHS, 1996b).                                             
                                                                                
     Photographs of the ocular fundus were taken to determine the presence      
     of diabetic retinopathy, age-related maculopathy, and other retinal        
     diseases that are the leading causes of vision loss in the United          
     States.  A non-stereoscopic, color, 45-degree photograph, centered         
     between the optic nerve and the macula, was taken of one randomly          
     selected eye.  The camera used was a Canon CR4-45NM "non-mydriatic"        
     fundus camera, which incorporated the use of an infrared video camera      
     to allow photographs to be taken in a darkened examination room            
     without the use of dilating drops.                                         
                                                                                
     In a darkened room, the sphincter muscle of the iris normally relaxes,     
     allowing for dilation of the pupil, usually to 6-10 mm in diameter.        
     The technician observed the eye's natural dilation on a special video      
     monitor and took the color photograph with a single flash of white         
     light.  If the examinee wore a contact lens, the photograph was taken      
     directly through the contact lens.  The entire procedure usually took      
     less than six minutes.  Detailed information on the examination            
     procedure is in the Fundus Photography chapter of the Health               
     Technician's Manual (U.S. DHHS, 1996b).                                    
                                                                                
     The exposed film was mailed to the University of Wisconsin-Madison,        
     Department of Ophthalmology, where it was processed by a local             
     laboratory into transparencies that were evaluated for photographic        
     quality.                                                                   
                                                                                
     The ocular fundus images on the final transparencies were reviewed by      
     photograph graders to assess the presence of diabetic retinopathy,         
     age-related maculopathy, and other retinal diseases.  The grading          
     system used for classifying diabetic retinopathy was based on a            
                                                                               
                                                                                
                                                                                
     modification of the Airlie House Classification Scheme (Diabetic           
     Retinopathy Study Group, 1981; Klein, 1984; Klein, 1986; The Early         
     Treatment Diabetic Retinopathy Study Group, 1991).                         
                                                                                
     The Modified Airlie House Classification of Diabetic Retinopathy slide     
     standards consist of 27 stereo pairs of color fundus photographs of        
     diabetic retinopathy and one slide depicting poor photographic quality.    
     The standard slides show diabetic proliferative disease and are used for   
     grading the severity of diabetic retinopathy.  The set is available with   
     a detailed chapter outlining its use and a sample grading form.            
     Additional information is available from The Fundus Photograph Reading     
     Center, c/o Michael Neider, WARF Building Room 450, 610 Walnut Street,     
     Madison, WI  53705.                                                        
                                                                                
     The fundus photography consultant provided extensive training to           
     technicians at their time of hire, and each technician's performance       
     was monitored in the field on a periodic basis.                            
                                                                                
     Two sources of nonsampling or measurement error were monitored             
     throughout the survey, the picture taking procedure and the image          
     grading procedure.  To ensure that adequate photographs were taken,        
     the technicians' performance was monitored by a review of photographs      
     at the University of Wisconsin and by review and retraining field          
     visits.  To evaluate the grading procedure, 1500 transparencies were       
     chosen at random for use in assessing inter- and intra-grader              
     reliability.  The Kappa statistic was chosen to assess agreement           
     (Fleiss, 1981).  The measures of agreement were generally good to          
     excellent and improved across time.                                        
                                                                                
     Data processing and editing were performed to ensure internal data         
     consistency.  Notes have been provided for variables requiring             
     additional explanation.                                                    
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
           INTRODUCTORY INFORMATION AND CONDITIONS AFFECTING RESULTS            
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
             6000          Photo taken?                             See note    
      FPPPHOTO     9239    1     Yes                                            
                    209    2     No                                             
                    289    8     Blank but applicable                           
                  21574    Blank                                                
                                                                                
             6001          Eye color: right eye                                 
      FPP1A        1995    1     Blue                                           
                   1567    2     Other                                          
                   5301    3     Brown                                          
                    874    8     Blank but applicable                           
                  21574    Blank                                                
                                                                                
             6002          Eye color: left eye                                  
      FPP1B        1991    1     Blue                                           
                   1572    2     Other                                          
                   5300    3     Brown                                          
                    874    8     Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6003-6004          Pupil size before dilation in normal                 
      FPP2                 room light (mm)                                      
                   9102    00-10                                                
                    635    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6005-6006          Pupil size during photography as                     
      FPP3                 measured on camera monitor (mm)                      
                   9058    00-12                                                
                    679    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6007-6008          Elapsed time between darkening room and              
      FPP4MIN              taking photograph (min)                              
                   9059    00-50                                                
                    678    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
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                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
           INTRODUCTORY INFORMATION AND CONDITIONS AFFECTING RESULTS            
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6009-6010          Elapsed time between darkening room and              
      FPP4SEC              taking photograph (sec)                              
                   9057    00-59                                                
                    680    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6011-6015          Photographer                                         
      FPPPHTG      9456    01001-09018                                          
                    281    88888 Blank but applicable                           
                  21574    Blank                                                
                                                                                
             6016          Eye                                                  
      FPPEYE       4436    1     Right                                          
                   4470    2     Left                                           
                    831    8     Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6017-6019          Grader code                                          
      FPP1005      4209    016   1st grader                                     
                   4864    102   2nd grader                                     
                    664    888   Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6020-6021          Fundus                                   See note    
      FPP1020       163    00    Absent (End)                                   
                   8910    02    Present                                        
                    664    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6022-6023          Focus                                                
      FPP1030      6721    00    Good/fair                                      
                   1235    01    Borderline (can't grade small                  
                                 microaneurysms or drusen)                      
                    954    02    Poor                                           
                    827    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
           INTRODUCTORY INFORMATION AND CONDITIONS AFFECTING RESULTS            
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6024-6025          Field definition                                     
      FPP1041      6418    00    Good                                           
                   2228    01    Fair                                           
                    206    02    Poor                                           
                     58    08    Can't grade                                    
                    827    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6026-6027          Horizontal field definition                          
      FPP1046      7040    00    Good                                           
                    514    01    Temporal                                       
                   1295    02    Nasal                                          
                     61    08    Can't grade                                    
                    827    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6028-6029          Vertical field definition                            
      FPP1047      7529    00    Good                                           
                   1108    01    High                                           
                    197    02    Low                                            
                     76    08    Can't grade                                    
                    827    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6030-6031          Artifact present                                     
      FPP1050      2035    00    None                                           
                   6875    02    Yes                                            
                    827    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6032-6033          Type of artifact: haze                               
      FPP1051      3756    00    None                                           
                   5154    02    Yes                                            
                    827    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
           INTRODUCTORY INFORMATION AND CONDITIONS AFFECTING RESULTS            
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6034-6035          Type of artifact: dust/dirt                          
      FPP1052      7291    00    None                                           
                   1619    02    Yes                                            
                    827    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6036-6037          Type of artifact: lashes                             
      FPP1053      8328    00    None                                           
                    582    02    Yes                                            
                    827    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6038-6039          Type of artifact: arc                                
      FPP1054      8477    00    None                                           
                    433    02    Yes                                            
                    827    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6040-6041          Type of artifact: uneven illumination,               
      FPP1055              center                                               
                   7950    00    None                                           
                    960    02    Yes                                            
                    827    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6042-6043          Type of artifact: uneven illumination,               
      FPP1056              edge                                                 
                   8497    00    None                                           
                    413    02    Yes                                            
                    827    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6044-6045          Type of artifact: central dot                        
      FPP1057      6545    00    None                                           
                   2365    02    Yes                                            
                    827    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
           INTRODUCTORY INFORMATION AND CONDITIONS AFFECTING RESULTS            
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6046-6047          Type of artifact: other                              
      FPP1059      8638    00    None                                           
                    272    02    Yes                                            
                    827    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6048-6049          Gradability                              See note    
      FPP1060      7298    00    Entire field gradable                          
                     30    01    Disc ungradable                                
                    764    02    Portion of macula ungradable                   
                    357    03    Macula ungradable                              
                     77    04    Portion of disc/macula ungradable              
                     77    05    Disc and macula ungradable                     
                    307    06    Entire field ungradable (End)                  
                    827    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
                                    FINDINGS                                    
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6050-6052          Diabetic retinopathy level               See note    
      FPP1070      7523    010   No retinopathy                                 
                     93    011   Questionable retinopathy                       
                     55    012   Non-diabetic retinopathy                       
                     30    014   Hard exudates, soft exudates,                  
                                 intraretinal microvascular                     
                                 abnormalities (IRMA), without                  
                                 microaneurysms                                 
                     66    015   Hemorrhages only, no microaneurysms            
                    219    020   Microaneurysms only                            
                    113    031   Early non-proliferative diabetic               
                                 retinopathy                                    
                     82    041   Moderate non-proliferative diabetic            
                                 retinopathy                                    
                     14    051   Severe non-proliferative diabetic              
                                 retinopathy                                    
                      5    060   Fibrous proliferation only                     
                      5    065   Proliferative diabetic retinopathy             
                                 (PDR) less than diabetic                       
                                 retinopathy standards (DRS) high               
                                 risk characteristics (HRC)                     
                                 for severe visual loss                         
                      3    070   PDR greater than or equal to                   
                                 DRS HRC for severe visual loss                 
                    395    088   Can't grade                                    
                   1134    888   Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6053-6054          Hemorrhages or microaneurysms                        
      FPP1080      7579    00    None                                           
                     92    01    Questionable                                   
                    521    02    Less than DRS 2A                               
                     18    03    Greater than or equal to DRS 2A                
                    393    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
                                    FINDINGS                                    
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6055-6056          Hard exudates                                        
      FPP1090      8055    00    None                                           
                     38    01    Questionable                                   
                     61    02    Less than DRS 3                                
                     99    03    Greater than or equal to DRS 3                 
                    350    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6057-6058          Soft exudates                                        
      FPP1100      8180    00    None                                           
                     36    01    Questionable                                   
                    118    02    Present                                        
                    269    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6059-6060          Intraretinal microvascular abnormalities             
      FPP1110              (IRMA)                                               
                   8107    00    None                                           
                     37    01    Questionable                                   
                     43    02    Present                                        
                    416    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6061-6062          Venous beading                                       
      FPP1120      8345    00    None                                           
                      8    01    Questionable                                   
                      5    02    Present                                        
                    245    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
                                    FINDINGS                                    
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6063-6064          New vessels in disc                                  
      FPP1130      8463    00    None                                           
                      7    01    Questionable                                   
                      1    02    Less than DRS 10A                              
                      2    03    Greater than or equal to DRS 10A               
                    130    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6065-6066          New vessels elsewhere                                
      FPP1140      8423    00    None                                           
                      6    01    Questionable                                   
                      4    02    Less than 1/2 disc area                        
                      1    03    Greater than or equal to 1/2 disc              
                                 area                                           
                    169    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6067-6068          Fibrous proliferation                                
      FPP1150      8482    00    None                                           
                      6    01    Questionable                                   
                      6    02    Fibrous proliferation elsewhere                
                                 (FPE) only                                     
                      1    03    Fibrous proliferation disc (FPD)               
                                 only                                           
                      3    04    FPE and FPD                                    
                    105    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6069-6070          Pre-retinal hemorrhage or vitreous                   
      FPP1160              hemorrhage                                           
                   8498    00    None                                           
                      3    01    Questionable                                   
                      1    02    Preretinal hemorrhage (PRH) only               
                      1    03    Vitreous hemorrhage (VH) only                  
                    100    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
                                    FINDINGS                                    
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6071-6072          Other abnormalities                                  
      FPP1170      6266    00    No                                             
                   2337    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6073-6074          Degeneration of retinal pigment                      
      FPP1172              epithelium (RPE)                                     
                   8321    00    None                                           
                    138    01    Questionable                                   
                    144    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6075-6076          Central circle RPE degeneration                      
      FPP1173      8485    00    None                                           
                    118    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6077-6078          Geographic atrophy                                   
      FPP1174      8563    00    None                                           
                      8    01    Questionable                                   
                     32    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6079-6080          Central circle geographic atrophy                    
      FPP1175      8576    00    None                                           
                     27    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6081-6082          Sub-retinal hemorrhage                               
      FPP1176      8592    00    None                                           
                      3    01    Questionable                                   
                      8    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
                                    FINDINGS                                    
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6083-6084          Central circle sub-retinal hemorrhage                
      FPP1177      8600    00    None                                           
                      3    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6085-6086          Sub-retinal fibrous scar                             
      FPP1178      8579    00    None                                           
                      3    01    Questionable                                   
                     21    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6087-6088          Central circle sub-retinal fibrous scar              
      FPP1179      8584    00    None                                           
                     19    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6089-6090          Sensory serous (sub-retinal) detachment              
      FPP1180      8573    00    None                                           
                     19    01    Questionable                                   
                     11    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6091-6092          Central circle sensory serous (sub-                  
      FPP1181              retinal) detachment                                  
                   8594    00    None                                           
                      9    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6093-6094          Hyperpigmentation                                    
      FPP1182      8360    00    None                                           
                     58    01    Questionable                                   
                    185    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
                                    FINDINGS                                    
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6095-6096          Central circle hyperpigmentation                     
      FPP1183      8463    00    None                                           
                    140    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6097-6098          Chorioretinal abnormalities, other                   
      FPP1184      8542    00    None                                           
                      7    01    Questionable                                   
                     54    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6099-6100          Central circle chorioretinal                         
      FPP1185              abnormalities, other                                 
                   8575    00    None                                           
                     28    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6101-6102          Peripapillary atrophy                                
      FPP1186      8196    00    None                                           
                     91    01    Questionable                                   
                    316    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6103-6104          Branch or central artery occlusion                   
      FPP1188      8598    00    None                                           
                      2    01    Questionable                                   
                      3    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6105-6106          Central circle branch or central artery              
      FPP1189              occlusion                                            
                   8602    00    None                                           
                      1    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
                                    FINDINGS                                    
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6107-6108          Branch vein occlusion                                
      FPP1190      8560    00    None                                           
                     19    01    Questionable                                   
                     24    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6109-6110          Central circle branch vein occlusion                 
      FPP1191      8600    00    None                                           
                      3    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6111-6112          Central vein occlusion                               
      FPP1192      8600    00    None                                           
                      3    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6113-6114          Central circle central vein occlusion                
      FPP1193      8601    00    None                                           
                      2    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6115-6116          Significant arterio-venous nicking                   
      FPP1194      8536    00    None                                           
                     36    01    Questionable                                   
                     31    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6117-6118          Hollenhorst plaque                                   
      FPP1196      8588    00    None                                           
                      9    01    Questionable                                   
                      6    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
                                    FINDINGS                                    
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6119-6120          Central circle Hollenhorst plaque                    
      FPP1197      8603    00    None                                           
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6121-6122          Asteroid hyalosis                                    
      FPP1198      8559    00    None                                           
                      5    01    Questionable                                   
                     39    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6123-6124          Central circle asteroid hyalosis                     
      FPP1199      8579    00    None                                           
                     24    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6125-6126          Nevus                                                
      FPP1200      8469    00    None                                           
                     54    01    Questionable                                   
                     80    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6127-6128          Central circle nevus                                 
      FPP1201      8595    00    None                                           
                      8    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6129-6130          Surface wrinkling retinopathy                        
      FPP1202      8017    00    None                                           
                    165    01    Questionable                                   
                    421    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
                                    FINDINGS                                    
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6131-6132          Central circle surface wrinkling                     
      FPP1203              retinopathy                                          
                   8466    00    None                                           
                    137    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6133-6134          Abnormal disc                                        
      FPP1204      8568    00    None                                           
                     18    01    Questionable                                   
                     17    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6135-6136          Large cup-to-disc ratio                              
      FPP1205      8078    00    None                                           
                    333    01    Questionable                                   
                    192    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6137-6138          Histoplasmosis (POHS)                                
      FPP1206      8596    00    None                                           
                      2    01    Questionable                                   
                      5    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6139-6140          Central circle histoplasmosis (POHS)                 
      FPP1207      8601    00    None                                           
                      2    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
                                    FINDINGS                                    
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6141-6142          Clinically significant macular edema                 
      FPP1208              based on hard exudates                               
                   8560    00    None                                           
                     16    01    Questionable                                   
                     27    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6143-6144          Central circle clinically significant                
      FPP1209              macular edema based on hard exudates                 
                   8580    00    None                                           
                     23    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6145-6146          Retinal detachment                                   
      FPP1210      8599    00    None                                           
                      1    01    Questionable                                   
                      3    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6147-6148          Central circle retinal detachment                    
      FPP1211      8603    00    None                                           
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6149-6150          Photocoagulation treatment in arcades                
      FPP1212      8578    00    None                                           
                      4    01    Questionable                                   
                     21    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
                                    FINDINGS                                    
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6151-6152          Photocoagulation treatment outside                   
      FPP1214              arcades                                              
                   8581    00    None                                           
                      2    01    Questionable                                   
                     20    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6153-6154          Other miscellaneous abnormalities                    
      FPP1220      8059    00    None                                           
                     97    01    Questionable                                   
                    447    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6155-6156          Other miscellaneous central circle                   
      FPP1221              abnormalities                                        
                   8563    00    None                                           
                     40    02    Yes                                            
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6157-6158          Answer drusen questions                              
      FPP1228      1620    00    No                                             
                   6867    02    Yes                                            
                    116    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6159-6160          Hard drusen                              See note    
      FPP1230      1824    00    None                                           
                    849    01    Questionable                                   
                   5511    02    Yes                                            
                    419    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
                                    FINDINGS                                    
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6161-6162          Soft drusen                              See note    
      FPP1240      7167    00    None                                           
                    391    01    Questionable                                   
                    926    02    Yes                                            
                    119    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6163-6164          Drusen area: grid                        See note    
      FPP1250      3391    00    None                                           
                   2786    01    Less than a circle of 95 microns in            
                                 diameter (standard circle C0)                  
                   1719    02    Less than a circle of 375 microns              
                                 in diameter (standard circle C2)               
                    351    03    Less than a circle of 960 microns              
                                 in diameter (standard circle O2)               
                    147    04    Greater than or equal to a circle              
                                 of 960 microns in diameter                     
                                 (standard circle O2)                           
                    209    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6165-6166          Drusen area: outside                     See note    
      FPP1260      5096    00    None                                           
                   2131    01    Less than a circle of 95 microns in            
                                 diameter (standard circle C0)                  
                    872    02    Less than a circle of 375 microns              
                                 in diameter (standard circle C2)               
                    213    03    Less than a circle of 960 microns              
                                 in diameter (standard circle O2)               
                    132    04    Greater than or equal to a circle              
                                 of 960 microns in diameter                     
                                 (standard circle O2)                           
                    159    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
                                    FINDINGS                                    
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6167-6168          Drusen area: central circle              See note    
      FPP1262      5513    00    None                                           
                   1881    01    Less than a circle of 95 microns in            
                                 diameter (standard circle C0)                  
                    561    02    Less than a circle of 375 microns              
                                 in diameter (standard circle C2)               
                    125    03    Less than a circle of 960 microns              
                                 in diameter (standard circle O2)               
                     16    04    Greater than or equal to a circle              
                                 of 960 microns in diameter                     
                                 (standard circle O2)                           
                    507    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6169-6170          Drusen area: inner circle                See note    
      FPP1264      4063    00    None                                           
                   2682    01    Less than a circle of 95 microns in            
                                 diameter (standard circle C0)                  
                   1308    02    Less than a circle of 375 microns              
                                 in diameter (standard circle C2)               
                    251    03    Less than a circle of 960 microns              
                                 in diameter (standard circle O2)               
                    122    04    Greater than or equal to a circle              
                                 of 960 microns in diameter                     
                                 (standard circle O2)                           
                    177    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6171-6172          Central circle soft drusen               See note    
      FPP1266      7772    00    None                                           
                     71    01    Questionable                                   
                    297    02    Yes                                            
                    463    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                                                                                
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                               FUNDUS PHOTOGRAPHY                               
    ------------------------------------------------------------------------    
                                 SUMMARY SCORES                                 
    ------------------------------------------------------------------------    
    Positions            Item description                                       
    SAS name    Counts       and code                               Notes       
    ------------------------------------------------------------------------    
                                                                                
        6173-6174          Summary diabetic retinopathy score       See note    
      FPPSURET     7764    00    None                                           
                    327    01    Mild                                           
                     94    02    Moderate                                       
                     26    03    Proliferative                                  
                    392    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6175-6176          Summary age-related maculopathy score    See note    
      FPPSUMAC     7268    00    None                                           
                    885    01    Early                                          
                     55    02    Late                                           
                    395    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
        6177-6178          Summary drusen score                     See note    
      FPPSUDRU     1979    00    None                                           
                    867    01    Questionable                                   
                   5640    02    Present                                        
                    117    08    Can't grade                                    
                   1134    88    Blank but applicable                           
                  21574    Blank                                                
                                                                                
                                                                               
                        NHANES III Examination Data File                        
                                                                                
    ------------------------------------------------------------------------    
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
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    NOTES                                                                       
                                                                                
                                                                                
     FPP1020:  Fundus                                                           
                                                                                
          When the fundus was absent (FPP1020=00), the grader was               
          instructed to stop.  All ensuing fields, FPP1030 through FPP1270,     
          were then left blank by the grader.  During data processing, the      
          blank fields were recoded "88  Blank but applicable."                 
                                                                                
                                                                                
     FPP1060:  Gradability status                                               
                                                                                
          Not all photographs were gradable.  The principal reasons were        
          related to the camera (e.g., malfunction, poor focus, dirty lens)     
          and to the examinee (e.g., cataracts, eye movement, corneal           
          change, poor pupil dilation, lens implants).  The grader was          
          instructed to stop when the entire field was ungradable               
          (FPP1060=06), at which point the remaining fields were left           
          blank.  During data processing, the blank fields were recoded "88     
          Blank but applicable."                                                
                                                                                
                                                                                
     FPP1070:  Diabetic retinopathy level                                       
                                                                                
          This variable represents the current state of severity of retinopathy 
          in the eye.  As such, it differs from the summary diabetic retinopathy
          score (FPPSURET) which represents the combination of current and past 
          retinopathy status.                                                   
                                                                                
                                                                                
     FPP1230-FPP1266:  Drusen details                                           
                                                                                
          Drusen vary in appearance, merging at one end of the spectrum         
          with the normal fundus background and at the other end with           
          diffuse degeneration of the retinal pigment epithelium.  Typical      
          small drusen usually appear as individual, round, flat spots in       
          the plane of the retinal pigment epithelium.  They may be pale        
          yellowish-white, contrasting sharply with the surrounding retinal     
          pigment epithelium, or only slightly more pale than the retinal       
          pigment epithelium and easily overlooked, even with careful           
          examination of well-focused photographs.  Larger drusen typically     
          are yellow-white in color and often have visible thickness.  Some     
          have sharp margins and a solid, nodular appearance, whereas           
          others have indistinct margins and a softer, more liquid              
          appearance.  Drusen may be distributed as individual spots or may     
          appear to merge with adjacent drusen.                                 
                                                                                
          In NHANES III, two characteristics of drusen type (hard or soft)      
          and area were graded in a semi-quantitative fashion within and        
          outside the grid.  Small punctate drusen (usually less than 95        
          microns in diameter) were classified as hard drusen; larger           
          drusen were classified as soft.  No attempt was made to further       
          characterize soft drusen by appearance as soft distinct or            
          indistinct.                                                           
                                                                               
                                                                                
          Drusen area was estimated within a central circle of the grid,        
          within the grid, and outside the grid.  The area covered by           
          drusen was estimated by mentally moving together all hard or soft     
          drusen as if they were confluent and comparing this area with         
          those of standard circles.  The estimate of drusen area was           
          classified into one of four categories:  smaller than a circle        
          with a diameter of 95 microns (comparable to the 63-micron            
          diameter circle used in a 30-degree field), smaller than a circle     
          with a diameter of 375 microns (250-micron diameter in a              
          30-degree field), smaller than a circle with a diameter of 960        
          microns (640-micron diameter in a 30-degree field), or equal to       
          or larger than a circle with a diameter of 960 microns.               
                                                                                
                                                                                
     FPPPHOTO:  Photographic status                                             
                                                                                
          Fundus photographs were not taken on all examinees who came to        
          the mobile examination center.  The principal reasons were            
          refusal to cooperate, equipment failure, physical inability, and      
          insufficient time.                                                    
                                                                                
                                                                                
     FPPSUDRU:  Summary drusen score                                            
                                                                                
          The summary drusen score was derived from a combination of values     
          from several variables.                                               
                                                                                
          Definite drusen present:  FPP1230, hard drusen, and/or FPP1240,       
          soft drusen, were coded "02  Yes."                                    
                                                                                
          Questionable drusen present:  Definite drusen were not present,       
          and FPP1230, hard drusen, and/or FPP1240, soft drusen, were/was       
          coded "01  Questionable."                                             
                                                                                
          No drusen present:  Neither definite nor questionable drusen was      
          present, and FPP1230, hard drusen, and/or FPP1240, soft drusen,       
          were/was coded "00  None."                                            
                                                                                
          Cannot grade drusen:  FPP1230, hard drusen, and FPP1240, soft         
          drusen, were both coded "08  Can't grade."                            
                                                                                
          Blank but applicable:  FPP1060, gradability, was coded "06            
          Entire field ungradable," or FPP1020, fundus, was coded "00           
          Absent" or "88  Blank but applicable."                                
                                                                                
                                                                                
     FPPSUMAC:  Summary age-related maculopathy score                           
                                                                                
          The summary age-related maculopathy score was derived from a          
          combination of values from several variables.  A detailed             
          description of lesions as defined by the Wisconsin Age-Related        
          Maculopathy Grading System is available (Klein, 1991; NTIS,           
          1991).                                                                
                                                                               
          Late age-related maculopathy:  At least one of the following          
          variables was coded "02  Yes."                                        
                                                                                
             FPP1174, geographic atrophy                                        
             FPP1176, sub-retinal hemorrhage                                    
             FPP1178, sub-retinal fibrous scar                                  
             FPP1180, sensory serous (sub-retinal) detachment                   
                                                                                
          Early age-related maculopathy:  At least one of the following         
          three sets of conditions was met.                                     
                                                                                
             FPP1172, degeneration of retinal pigment epithelium (RPE),         
             was coded "02  Yes," and (FPP1230, hard drusen, and/or             
             FPP1240, soft drusen, were/was coded "02  Yes").                   
                                                                                
             FPP1182, hyperpigmentation, was coded "02 Yes," and                
             (FPP1230, hard drusen, and/or FPP1240, soft drusen, were/was       
             coded "02 Yes").                                                   
                                                                                
             FPP1240, soft drusen, was coded "02  Yes," and FPP1250, grid       
             area, was coded 02-04 (equal to or greater than a circle 95        
             microns in diameter).                                              
                                                                                
          No age-related maculopathy:  Early and late age-related               
          maculopathy definitions were not met, and FPP1240, soft drusen,       
          was coded 00-02 (gradable).                                           
                                                                                
          "Cannot grade" age-related maculopathy:  Early and late               
          age-related maculopathy definitions were not met, and FPP1240,        
          soft drusen, was coded "08  Can't grade."                             
                                                                                
          Blank but applicable:  FPP1060, gradability, was coded "06            
          Entire field ungradable," or FPP1020, fundus, was coded "00           
          Absent" or "88  Blank but applicable."                                
                                                                                
                                                                                
     FPPSURET:  Summary diabetic retinopathy score                              
                                                                                
          The summary diabetic retinopathy score was derived from a             
          combination of values from several variables.  That is, it            
          combines the diabetic retinopathy level variable (FPP1070) and        
          history of treatment for proliferative diabetic retinopathy           
          (using the photocoagulation treatment outside the arcades             
          variable (FPP1214) as a marker).  A detailed description of           
          lesions as defined by The Early Treatment Diabetic Retinopathy        
          Study (ETDRS) is available in the ETDRS report #10 (The Early         
          Treatment Diabetic Retinopathy Study, 1991).  The NHANES III          
          fundus photo grading protocol (NTIS, 1995) describes methods of       
          assigning diabetic levels.                                            
                                                                               
                                                                                
          Proliferative diabetic retinopathy:  At least one of the              
          following two sets of conditions was met.                             
                                                                                
             FPP1070, diabetic retinopathy level, was coded 060-070.            
                                                                                
             FPP1070, diabetic retinopathy level, has a code of anything        
             other than "012  Non-diabetic retinopathy," and FPP1214,           
             photocoagulation treatment outside arcades, was coded "02          
             Yes."                                                              
                                                                                
          Moderate/severe non-proliferative retinopathy:  FPP1070, diabetic     
          retinopathy level, was coded "041  Moderate non-proliferative" or     
          "051  Severe non-proliferative."                                      
                                                                                
          Mild non-proliferative retinopathy:  FPP1070, diabetic                
          retinopathy level, was coded "020  Microaneurysms only" or "031       
          Early non-proliferative."                                             
                                                                                
          No diabetic retinopathy:  FPP1070, diabetic retinopathy level,        
          was coded 010-015.                                                    
                                                                                
          "Cannot grade" diabetic retinopathy:  FPP1070, diabetic               
          retinopathy level, was coded "088  Can't grade."                      
                                                                                
          Blank but applicable:  FPP1060, gradability, was coded "06            
          Entire field ungradable," or FPP1020, fundus, was coded "00           
          Absent" or "88  Blank but applicable."