[Federal Register Volume 72, Number 146 (Tuesday, July 31, 2007)]
[Notices]
[Pages 41796-41808]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 07-3708]


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SOCIAL SECURITY ADMINISTRATION

[Docket No. SSA-2007-0029]


Social Security Ruling, SSR 07-01p; Titles II and XVI: Evaluating 
Visual Field Loss Using Automated Static Threshold Perimetry

AGENCY: Social Security Administration.

ACTION: Notice of Social Security Ruling.

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SUMMARY: In accordance with 20 CFR 402.35(b)(1), the Commissioner of 
Social Security gives notice of Social Security Ruling, SSR 07-01p. 
This Ruling clarifies how we use automated static threshold perimetry 
to determine statutory blindness based on visual field loss.

EFFECTIVE DATE: July 31, 2007.

FOR FURTHER INFORMATION CONTACT: Michelle Hungerman, Office of 
Disability Programs, Social Security Administration, 6401 Security 
Boulevard, Baltimore, MD 21235-6401, (410) 965-2289 or TTY 1-800-325-
0778.

SUPPLEMENTARY INFORMATION: Although 5 U.S.C. 552(a)(1) and (a)(2) do 
not require us to publish this Social Security Ruling, we are doing so 
in accordance with 20 CFR 402.35(b)(1).
    Social Security Rulings make available to the public precedential 
decisions relating to the Federal old-age, survivors, disability, 
supplemental security income, special veterans benefits, and black lung 
benefits programs. Social Security Rulings may be based on 
determinations or decisions made at all administrative levels of 
adjudication, Federal court decisions, Commissioner's decisions, 
opinions of the Office of the General Counsel, and policy 
interpretations of the law and regulations.
    Although Social Security Rulings do not have the same force and 
effect as the statute or regulations, they are binding on all 
components of the Social Security Administration, in accordance with 20 
CFR 402.35(b)(1), and are binding as precedents in adjudicating cases.
    If this Social Security Ruling is later superseded, modified, or 
rescinded, we will publish a notice in the Federal Register to that 
effect.

(Catalog of Federal Domestic Assistance, Program Nos 96.001 Social 
Security--Disability Insurance; 96.006 Supplemental Security 
Income.)


    Dated: May 30, 2007.
Michael J. Astrue,
Commissioner of Social Security.

Policy Interpretation Ruling

Titles II and XVI: Evaluating Visual Field Loss Using Automated Static 
Threshold Perimetry

    Purpose: To clarify how we use automated static threshold perimetry 
to evaluate visual field loss.
    Citations (Authority): Sections 205(a), 216(i)(1), 221, 223(d), 
1614(a), 1631(d), and 1633 of the Social Security Act (Act), as 
amended; Regulations No. 4, subpart P, sections 404.1520, 404.1525, 
404.1526, 404.1581, and 2.00A, 2.03, 102.00A, and 102.03 of appendix 1; 
and Regulations No.16, subpart I, sections 416.920, 416.924, 416.925, 
416.926, and 416.981.
    Pertinent History: The Act provides for a finding of blindness 
based on visual field loss when the widest diameter of the visual field 
in the better eye subtends an angle no greater than 20 degrees. Even 
when visual field loss does not result in blindness, it may 
nevertheless be disabling. In sections 2.00A6 and 102.00A6 of the 
Listing of Impairments in appendix 1 to subpart P of part 404 (the 
listings) we provide that when we need to measure the extent of visual 
field loss, we will use visual field measurements obtained with an 
automated static threshold perimetry test that satisfies our 
requirements.\1\
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    \1\ Our rules provide that in addition to automated static 
threshold perimetry we can use comparable visual field measurements 
obtained with kinetic perimetry, such as Goldmann perimetry. Because 
we allow for different types of testing, our listings provide 
comparable criteria that can be used with the different types of 
test results. Accordingly, only one type of testing is needed to 
evaluate visual field loss under our listings.
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    Automated static threshold perimetry measures the retina's 
sensitivity to light at predetermined locations in the visual field. 
While the individual focuses on a specific point, called the point of 
fixation, stimuli are presented in random order at each of the 
predetermined locations within the visual field. The size of the 
stimulus and the locations tested remain constant, but the intensity 
(brightness) of the stimulus is varied in order to determine the level 
at which the individual sees the stimulus. The intensity level where 
the individual sees the stimulus is referred to as the threshold. The 
threshold for each point tested is reported in decibels (dB).
    The results of automated static threshold perimetry are reported on 
standard charts. (See Exhibits 1 and 2 at the end of this ruling for 
examples of standard charts that may be found in case records.) These 
charts:
    <bullet> Identify the perimeter that was used to perform the test;
    <bullet> Provide identifying information about the test, such as 
the date of the test, the type of test used, the size and color of the 
stimulus, and the background illumination;
    <bullet> Provide the mean deviation (MD); \2\ and
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    \2\ The MD represents the average elevation or depression of the 
individual's visual field when compared to a normal field. This 
measurement is expressed in dB.
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    <bullet> Contain a printout that shows the threshold, in dB, for 
each of the locations tested. We refer to this printout, examples of 
which are shown below, as the dB printout.
    In this Ruling we explain:
    <bullet> How to use the information in the standard charts produced 
as part of automated static threshold perimetry to determine whether 
the visual field test satisfies our requirements. To illustrate this, 
we refer to standard charts produced by the Humphrey Field Analyzer. We 
refer only to the Humphrey Field Analyzer because it is the perimeter 
most widely used in the United States.
    <bullet> How to use the MD to determine whether the individual has 
visual field loss.
    <bullet> Our process for determining whether the test results show 
statutory blindness based on visual field loss.\3\
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    \3\ We developed our process to enable us to apply the results 
of automated static threshold perimetry to the standard for 
statutory blindness. Health care providers do not use our process in 
their clinical practices or for treatment purposes.
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    <bullet> How to evaluate cases in which severe visual field loss 
has not resulted in statutory blindness.

[[Page 41797]]

    Policy Interpretation: We use the following process to evaluate 
automated static threshold perimetry.
    Step 1--Is the automated static threshold perimetry test 
acceptable?
    We consider an automated static threshold perimetry test to be 
acceptable when it meets all of the following requirements:
    <bullet> The test is performed on a perimeter that satisfies all of 
the requirements in sections 2.00A6a(ii) and 102.00A6a(ii) of the 
listings; \4\
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    \4\ As of the effective date of this ruling, all models of the 
Humphrey Field Analyzer satisfy these requirements.
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    <bullet> The test uses a white size III Goldmann stimulus and a 
31.5 apostilb (asb) \5\ (10 candela (cd)/m\2\) white background; \6\
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    \5\ An apostilb is a unit of luminance.
    \6\ The background color is not shown on the standard charts 
produced by the Humphrey Field Analyzer. However, as of the 
effective date of this ruling, the Humphrey Field Analyzer always 
uses a white background if a white stimulus is used.
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    <bullet> The points tested are no more than 6 degrees apart 
horizontally or vertically; and
    <bullet> The test measures the central 24 to 30 degrees of the 
visual field; that is, the area measuring 24 to 30 degrees around the 
point of fixation.
    The Humphrey Field Analyzer central 30-2 threshold test (HFA 30-2) 
and central 24-2 threshold test (HFA 24-2) are tests that can meet 
these criteria. The HFA 30-2 tests 76 points in the central 30 degrees 
of the visual field. The HFA 24-2 tests 54 points in the central 24 to 
30 degrees of the visual field. For both of these tests, the tested 
points are spaced in an equidistant grid pattern, with each point 6 
degrees apart horizontally or vertically from any adjacent point. 
Therefore, we consider the HFA 30-2 and the HFA 24-2 to be acceptable 
tests when performed using a size III white stimulus on a 31.5 asb 
white background.
    The following examples of dB printouts illustrate the grid patterns 
used for the HFA 30-2 and the HFA 24-2 and provide information for 
interpreting the test results.
BILLING CODE 2211-01-P

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Billing Code 2211-01-C

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    We will not use automated static threshold perimetry test results 
to evaluate the visual field loss if the test was not performed using 
all of our requirements; for example, a stimulus other than a size III 
stimulus was used, or the stimulus was not white.
    Step 2--Are the test results reliable?
    Each perimeter manufacturer will identify factors that are used to 
determine whether the test results are reliable.
    For the Humphrey Field Analyzer, the reliability factors are 
fixation losses, false positive errors, and false negative errors. 
Information about these factors is at the top of the chart (see 
Exhibits 1 and 2). The test results are not reliable for evaluating 
visual field loss if the fixation losses exceed 20 percent, or if the 
false positive errors or false negative errors exceed 33 percent.
    Even when the reliability factors are within the manufacturer's 
specifications, we will not use the test results to evaluate visual 
field loss if there is other information in the case file that suggests 
that the results are not valid; for example, the test results are 
inconsistent with the clinical findings or the individual's daily 
activities.
    Step 3--Does the individual have visual field loss?
    For acceptable tests performed on a Humphrey Field Analyzer, an MD 
equal to or greater than -5 dB (for example, -4.39, -2.58, or 0) 
indicates that the visual field is normal. An MD less than -5 dB (for 
example, -5.5, -8.85, or -11.18) indicates the individual has visual 
field loss.
    Step 4--Do the test results show statutory blindness based on 
visual field loss?
    In automated static threshold perimetry, the intensity of the 
stimulus varies. We measure the extent of visual field loss by 
determining the portion of the visual field in which the individual can 
see a white III4e stimulus. The ``III'' refers to the standard Goldmann 
test stimulus size III. The ``4e'' refers to the standard Goldmann 
filters used to determine the intensity of the stimulus. Therefore, a 
determination is needed as to the dB threshold level that corresponds 
to a 4e intensity for the particular perimeter being used. Points that 
are at this dB threshold level or above are considered seeing points 
because they are the same intensity or dimmer than a 4e stimulus. 
Points that are below this dB threshold level are considered non-seeing 
points because they are brighter than a 4e stimulus.
    For acceptable tests performed on a Humphrey Field Analyzer, a 10 
dB threshold is equivalent to a 4e intensity. Therefore, for these 
tests we consider any point with a threshold of 10 dB or higher to be a 
seeing point; we consider any point with a threshold of less than 10 dB 
to be a non-seeing point (see sections 2.00A6a(vii) and 102.00A6a(vii) 
of the listings).
    After we determine the dB threshold that is comparable to a 4e 
stimulus, we use the dB printout to determine whether the widest 
diameter of the field is less than or equal to 20 degrees. The diameter 
must go through the point of fixation.
    To determine whether the widest diameter is greater than 20 
degrees, we may map the visual field on a copy of the dB printout by 
drawing a line, which we refer to as a pseudoisopter, midway between 
the seeing and non-seeing points.\7\ For example, for acceptable tests 
performed on a Humphrey Field Analyzer, we draw the pseudoisopter 
between any two adjacent tested points when one threshold is 10 dB or 
greater and the other threshold is less than 10 dB. If any number at 
the outermost edge of the field is a seeing point, we draw the 
pseudoisopter on the edge of the field at that point. If more than one 
number is shown for a particular point, we use the higher number to 
determine whether the point is a seeing point. We include the map of 
the visual field in the case record.
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    \7\ A pseudoisopter is similar to an isopter drawn as part of 
kinetic visual field testing. Drawing a pseudoisopter assists in 
determining the location of the widest diameter of the visual field 
and whether that diameter is 20 degrees or less. However, we do not 
always need to draw a pseudoisopter to determine whether the widest 
diameter is 20 degrees or less. For example, if the only seeing 
points on the dB printout are the four locations around the point of 
fixation, we can determine that the widest diameter of the visual 
field is less than 20 degrees without drawing a pseudoisopter. If 
all the points in an entire quadrant of the dB printout are seeing 
points, we can determine that the widest diameter is greater than 20 
degrees.
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    The pseudoisopter(s) differentiates the seeing area of the visual 
field from the non-seeing area. We consider the pseudoisopter itself to 
be part of the seeing area.
    We determine whether the widest diameter is greater than 20 degrees 
by using the hash marks on the horizontal (x-) and vertical (y-) axes 
of the Humphrey Field Analyzer dB printout or by calculating the 
distance between the points. As shown above, for the HFA 30-2 and the 
HFA 24-2, each hash mark covers a distance of 10 degrees, and the 
degrees are divided evenly between the hash marks. Additionally, each 
tested point on a dB printout from an HFA 30-2 or an HFA 24-2 is 6 
degrees apart horizontally or vertically from any adjacent tested 
point. The four tested points immediately surrounding the point of 
fixation are each 3 degrees horizontally and vertically from the point 
of fixation. Any tested point adjacent to an axis is 3 degrees from 
that axis.
    When we measure the widest diameter of the visual field, we 
subtract the length of any scotoma (non-seeing area), other than the 
``normal'' blind spot,\8\ from the overall length of any diameter on 
which it falls. (On some Humphrey Field Analyzer dB printouts, the 
normal blind spot is identified by a small triangle, as shown in 
Example 1.) As previously noted, we consider the pseudoisopter to be a 
seeing area and do not subtract it from the overall length of the 
diameter.
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    \8\ The normal blind spot is usually located 15.5 degrees 
temporal to fixation (to the right for the right eye, to the left 
for the left eye) and 1.5 degrees below the horizontal meridian. It 
is approximately 5.5 degrees in width and 7.5 degrees in length.
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    We will determine that the individual has statutory blindness if 
the widest diameter in the better eye is less than or equal to 20 
degrees, this finding is consistent with the other evidence in the case 
record, and for title II, a medically determinable impairment that 
could result in the visual field loss has been identified.
    Examples of how we determine whether the individual has statutory 
blindness based on visual field loss.

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    To measure the widest diameter, we create a pseudoisopter by 
drawing a line midway between points with a threshold of 10 dB and 
higher and adjacent points with a threshold less than 10 dB, or by 
drawing the pseudoisopter on the edge of the tested area when the 
thresholds at the outermost points are 10 dB or higher. As all of the 
outermost points on the dB printout above are 10 dB or higher, we draw 
the pseudoisopter delineating the outer edge of the visual field around 
the tested area.
[GRAPHIC] [TIFF OMITTED] TN31JY07.020

    After determining the outer edge of the seeing area as shown on the 
dB printout, we need to determine whether there are any scotomata; that 
is, blind spots. If so, we map the scotomata as we do not consider them 
when we determine whether the widest diameter of the visual field is 
greater than 20 degrees. A scotoma is illustrated below.

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    As all of the thresholds in the lower left quadrant of this dB 
printout are higher than 10 dB, we consider this entire quadrant to be 
a seeing area. Any diameter that is drawn through this quadrant will be 
at least 30 degrees long. Therefore, without calculating the actual 
length of the widest diameter shown on the dB printout, we can 
determine that the widest diameter of this visual field must be greater 
than 20 degrees and that this individual does not have statutory 
blindness based on visual field loss.
    Although we did not need to calculate the widest diameter for this 
example, the widest diameter shown on this dB printout is 54 degrees on 
both axes. On the y-axis, the diameter extends from the top of the dB 
printout to the bottom of the dB printout, which is 60 degrees in 
length. However, there is a segment of the y-axis that is in the 
scotoma, the segment from 6 degrees to 12 degrees.\9\ This segment is 6 
degrees long (calculated on the y-axis by adding the 3 degrees above 
the non-seeing point to the 3 degrees below it). We subtract the 6 
degrees from the 60 degrees for a total diameter of 54 degrees.
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    \9\ We would not deduct the segments of the y-axis from the 
point of fixation to 6 degrees or from -6 to -12 degrees because 
those segments are part of the pseudoisopter and we consider the 
pseudoisopter to be a seeing area.
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    On the x-axis, the diameter extends from one side of the dB 
printout to the other side of the dB printout, which is 60 degrees in 
length. However, there is a segment of the x-axis that is in the 
scotoma, the segment from 12 degrees to 18 degrees.\10\ This segment is 
6 degrees long. We subtract the 6 degrees from the 60 degrees for a 
diameter of 54 degrees.
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    \10\ This segment includes the ``normal'' blind spot, which is 
usually not deducted from the visual field. However, because the 
area around the``normal'' blind spot is part of the non-seeing area, 
the ``normal'' blind spot is no longer considered ``normal'' and we 
include it as part of the scotoma.
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    To measure the widest diameter, we create a pseudoisopter by 
drawing a line midway between points with a threshold of 10 dB and 
higher and adjacent points with a threshold less than 10 dB.
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    The widest diameter is 24 degrees on the y-axis. We can determine 
that the individual does not have statutory blindness based on visual 
field loss because the widest diameter is greater than 20 degrees.
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    To measure the widest diameter, we create a pseudoisopter by 
drawing a line midway between points with a threshold of 10 dB or 
higher and adjacent points with a threshold less than 10 dB.

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    The widest diameter is shown below.
    [GRAPHIC] [TIFF OMITTED] TN31JY07.026
    
    The widest diameter is on a diagonal; therefore, we calculate its 
length as the hypotenuse of a right triangle.\11\ The widest diameter 
extends from the point in the field that is 6 degrees above and 12 
degrees to the left of the point of fixation, through the point of 
fixation, to the point in the field that is 3 degrees below and 6 
degrees to the right of the point of fixation. These two points are 9 
degrees apart vertically and 18 degrees apart horizontally, as shown 
below.
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    \11\ The formula for calculating the length of the hypotenuse of 
a right triangle is a\2\ + b\2\ = c\2\, where a and b represent the 
vertical and horizontal distances between two points and c 
represents the diagonal distance between two points.
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    To measure the widest diameter, we apply the formula for 
calculating the length of the hypotenuse of a right triangle as 
follows: 9\2\ + 18\2\ = 81 + 324 = 405. The widest diameter is the 
square root of 405, or 20.12 degrees, which we round to 20 degrees.\12\ 
Assuming that this is the individual's better eye, that the field shown 
is consistent with the other evidence in file, and for a title II 
claim, that there is a medically determinable impairment that could 
cause this field loss, we will find that the individual has statutory 
blindness.
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    \12\ When determining the widest diameter of the visual field, 
follow the normal rules for rounding to the nearest whole number; 
that is, round decimals below 0.5 down to the lower whole number and 
round decimals 0.5 and above up to the higher whole number.
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    Step 5--How do we evaluate severe visual field loss that has not 
resulted in statutory blindness?
    If the individual's visual disorder has resulted in severe visual 
field loss but has not resulted in statutory blindness, we will 
consider whether the visual disorder meets listing 2.03B or 102.03B. A 
visual disorder meets listing 2.03B or 102.03B when the MD for the 
better eye, measured with an HFA 30-2, is -22 dB or worse.\13\ If the 
visual disorder does not meet a listing, we will determine whether the 
visual disorder medically equals a listing or, if not, assess the 
limitations imposed by the visual disorder.
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    \13\ An HFA 24-2 cannot be used to determine if the visual 
disorder meets or medically equals listing 2.03B or 102.03B because 
the criterion in those listings was calculated using an HFA 30-2. An 
MD calculated using an HFA 24-2 cannot be substituted for an MD 
calculated using an HFA 30-2.
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BILLING CODE 4191-02-P

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    Effective Date: This Ruling is effective upon publication in the 
Federal Register.
    Cross-References: Program Operations Manual System DI 34001.012 and 
DI 34005.102; Special Senses and Speech--Adult, Program Policy Online 
104167188, Special Senses and Speech--Child, Program Policy Online 
734761857.
[FR Doc. 07-3708 Filed 7-30-07 8:45 am]
BILLING CODE 4191-02-C