Korean J Ophthalmol Vol.23, No.3, 2009 Table 3. Correlation of the American Medical Association functional vision scores to retinitis pigmentosa patients BCVA FAS FFS NEI-VFQ FVS BCVA FAS FFS r=0.69, p<0.001 r=0.73, p<0.001 r=0.94, p<0.001 r=0.86, p<0.001 r=0.38, p<0.001 r=0.39, p<0.001 r=0.58, p<0.001 r=0.60, p<0.001 r=0.60, p<0.001 r=0.44, p<0.001 BCVA=best-corrected visual acuity; FVS=functional vision score; FFS=functional field score; FAS=functional acuity score; NEI-VFQ =composite score. Spearman correlation analysis, two-sided p-values of <0.05 were considered statistically significant. Table 4. Comparison of functional acuity score and functional field score between the better visual acuity group and worse visual acuity group Better VA group (n=46) Worse VA group (n=62) FVS=functional vision score; FFS=functional field score; FAS=functional acuity score; VA=visual acuity. * Independent t-test, two-sided p-values of <0.05 were considered statistically significant. 34.7±9.7 35, 76 % 16.6±12.5 17.8±10.2 0.41±0.56 0.31±0.37 0.18±0.13 39.8±14.7 30, 48.2% 20.8±13.0 19.8±17.4 1.09±0.60 1.13±0.64 0.97±0.55 p-value* 0.03 0.84 0.13 0.49 <0.001 <0.001 <0.001 Variables Age (years) Gender (male %) Disease duration (years) Age of onset (years) BCVA OD OS BCVA, better eye (FFS), as defined in the aforementioned guidelines.10,11 VA measurements were converted to a visual acuity score (VAS). The weighted average of three VASs for each field was used to calculate the FAS according to: FAS=(VASOD+VASOS+3× VASOU)/5. To evaluate the FFS, the visual field score (VFS) for the right monocularfield (VFSOD), the left monocular field (VFSOS), and the binocular field (VFSOU) were first scored separately: FFS=(VFSOD+VFSOS+3×VFSOU)/5. The FAS and FFS were then multiplied to yield the FVS: FVS=FAS×FFS/100. The AMA FVS classification (Table 1) was used to classify patients.11 Self-Reported Questionnaire (NEI-VFQ 25) The NEI-VFQ 25-item version with appendix7,8 (a total of 39 items) was administered by skilled interviewers and scored in the standard manner. There were twelve sub-scale scores and one composite score. The NEI-VFQ 25 composite score was the average of all available sub-scales, except general health, and was suggested as the vision-related quality of life indicator by the NEI. Statistical analysis The correlations of the NEI-VFQ 25 composite score to the FVS, FFS, and FAS were analyzed by the Spearman correla- tion test. If the correlations were significant, Fisher’s Z-trans- formation analysis was used to determine the better predictor of vision-specific quality of life among the FVS, FFS, and FAS. 166 A regression analysis was performed to determine regression equations. As the median log MAR was 0.6, we divided the patients into two groups according to that value: the better VA group (logMAR<0.6), and the worse VA group (logMAR≥0.6). In each group, the relationship of theVFQ composite score to the FVS, FFS, and FAS was evaluated and regression analysis was performed. Statistical analyses were performed using SPSS v.12.0 software (SPSS Inc., Chicago, IL), and two-sided p- values of <0.05 were considered statistically significant. Results As stated above, there were 108 RP patients enrolled (65 males, 43 females) ranging in age from 16 to 85 years. The mean age of the subjects was 37.6±13.0 years. Their VA ranged from 0.0 to 2.3 log MAR. The demographics and descriptive stati- stics for the clinical measures of visionare listed in Table 2. Most participants were classified into more advanced categories (FVS 4, 5, 6). FVS was highly correlated to the BCVA (r=0.69, p<0.001), FFS (r=0.86, p<0.001) and the FAS (r=0.73, p<0.001) (Table 3). Significant correlations of the VFQ composite score to BCVA (r=0.60, p<0.001), FFS (r=0.44, p<0.001), FAS (r=0.60, p<0.001), FVS (r=0.58, p<0.001) were also found. However, we could not find any differences among the correlations of BCVA, FVS, FFS, and FAS to the VFQ composite score. Study patients were older in the poor VA group than in the better VA group (34.7±9.7 vs. 39.8±14.7, p=0.03, Table 4). Multiple regression analysis was performed as follows with the interactive forms of FFS and FAS. (All patients, n=112), NEI-FVQ composite=0.30×FAS+