a. Testing for visual fields.
(i) We generally need visual field testing when you have a visual disorder that could
result in visual field loss, such as glaucoma, retinitis pigmentosa, or optic neuropathy,
or when you display behaviors that suggest a visual field loss.
(ii) When we need to measure the extent of your visual field loss, we will use visual
field measurements obtained with an automated static threshold perimetry test performed
on a perimeter, like the Humphrey Field Analyzer, that satisfies all of the following
A. The perimeter must use optical projection to generate the test stimuli.
B. The perimeter must have an internal normative database for automatically comparing
your performance with that of the general population.
C. The perimeter must have a statistical analysis package that is able to calculate visual
field indices, particularly mean deviation.
D. The perimeter must demonstrate the ability to correctly detect visual field loss and
correctly identify normal visual fields.
E. The perimeter must demonstrate good test-retest reliability.
F. The perimeter must have undergone clinical validation studies by three or more independent
laboratories with results published in peer-reviewed ophthalmic journals.
(iii) The test must use a white size III Goldmann stimulus and a 31.5 apostilb (10cd/m2)
white background. The stimuli locations must be no more than 6 degrees apart horizontally
or vertically. Measurements must be reported on standard charts and include a description
of the size and intensity of the test stimulus.
(iv) To determine statutory blindness based on visual field loss (102.03A), we need
a test that measures the central 24 to 30 degrees of the visual field; that is, the
area measuring 24 to 30 degrees from the point of fixation. Acceptable tests include
the Humphrey 30–2 or 24–2 tests.
(v) The criterion in 102.03B is based on the use of a test performed on a Humphrey
Field Analyzer that measures the central 30 degrees of the visual field. We can also
use comparable results from other acceptable perimeters; for example, a mean defect
of 22 on an acceptable Octopus test, to determine that the criterion in 102.03B is
met. We cannot use tests that do not measure the central 30 degrees of the visual
field, such as the Humphrey 24–2 test, to determine if your impairment meets or medically
(vi) We measure the extent of visual field loss by determining the portion of the
visual field in which you can see a white III4e stimulus. The ‘‘III’’ refers to the
standard Goldmann test stimulus size III, and the ‘‘4e’’
refers to the standard Goldmann intensity filters used to determine the intensity
of the stimulus.
(vii) In automated static threshold perimetry, the intensity of the stimulus varies.
The intensity of the stimulus is expressed in decibels (dB). We need to determine
the dB level that corresponds to a 4e intensity for the particular perimeter being
used. We will then use the dB printout to determine which points would be seen at
a 4e intensity level. For example, in Humphrey Field Analyzers, a 10 dB stimulus
is equivalent to a 4e stimulus. A dB level that is higher than 10 represents a dimmer
stimulus, while a dB level that is lower than 10 represents a brighter stimulus. Therefore,
for tests performed on Humphrey Field Analyzers, any point seen at 10 dB or higher
is a point that would be seen with a 4e stimulus.
(viii) We can also use visual field measurements obtained using kinetic perimetry,
such as the Humphrey “SSA Test Kinetic” or Goldmann perimetry, instead of automated
static threshold perimetry. The kinetic test must use a white III4e stimulus projected
on a white 31.5 apostilb (10cd/m2) background. In automated kinetic tests, such as
the Humphrey “SSA Test Kinetic,” testing along a meridian stops when you see the stimulus.
Because of this, automated kinetic testing does not detect limitations in the central
visual field. If your visual disorder has progressed to the point at which it is
likely to result in a significant limitation in the central visual field, such as
a scotoma (see 102.00A8c), we will not use automated kinetic perimetry to evaluate
your visual field loss. Instead, we will assess your visual field loss using automated
static threshold perimetry or manual kinetic perimetry.
(ix) We will not use the results of visual field screening tests, such as confrontation
tests, tangent screen tests, or automated static screening tests, to determine that
your impairment meets or medically equals a listing, or functionally equals the listings.
However, we can consider normal results from visual field screening tests to determine
whether your visual disorder is severe when these test results are consistent with
the other evidence in your case record. (See § 416.924(c).) We will not consider
normal test results to be consistent with the other evidence if either of the following
A. The clinical findings indicate that your visual disorder has progressed to the point
that it is likely to cause visual field loss; or
B. You have a history of an operative procedure for retinal detachment.
b. Use of corrective lenses.
You must not wear eyeglasses during the visual field examination because they limit
your field of vision. Contact lenses or perimetric lenses may be used to correct
visual acuity during the visual field examination in order to obtain the most accurate
visual field measurements. For this single purpose, you do not need to demonstrate
that you have the ability to use the contact or perimetric lenses on a sustained basis.