Visual Field Assessment and Disability Evaluation (2025)
Chapter: Summary
Summary1
Visual field impairment is associated with a number of conditions, including glaucoma, optic neuropathies, and disorders affecting the retina and visual pathways. Significant loss of visual field impacts quality of life and can result in varying degrees of disability. This is particularly true with respect to a person’s daily functioning, including the ability to work and participate in school; social engagement; and emotional well-being. Individuals with moderate to severe visual field loss may have difficulty performing routine tasks such as reading, driving, and navigating different environments, which leads in turn to greater reliance on others and reduced independence. Visual field loss also limits the ability to engage in social activities, thereby reducing overall social participation and contributing to feelings of isolation. The degree of impact varies depending on the severity of the loss, with more profound loss leading to greater disability and poorer quality of life.
CONTEXT FOR THIS STUDY
Perimetry, also known as visual field testing, is an essential tool for assessing ophthalmic conditions that can result in visual field loss. Perimetry techniques consist of a combination of hardware, stimuli, testing patterns, and algorithms. These techniques form the complex and highly technical context for the present study. (See Box S-1 for definitions of the key technical terms used in this report.)
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1 This summary does not include references. Citations to support the discussion and conclusions herein are provided in the main text.
BOX S-1
Definitions of Key Terms Used in This Report
Visual field is the total area of space a person can see when the eyes are focused on a central point.
Visual field meridians refer to imaginary lines radiating from a center point that divide the visual field into equal sections, like pieces of a pie.
Visual perimeter device (perimeter) is a machine used to measure visual fields.
Visual perimetry is the systematic measurement of visual fields.
Automated perimetry refers to automated presentation of the test stimulus and recording of patient responses.
Static perimetry refers to stationary stimuli presented at defined points in the visual field. Locations at which the stimulus is seen and not seen are recorded.
Kinetic perimetry uses a moving stimulus that is generally moved from a nonseeing area to seeing area in a systematic way to map the central and peripheral visual field boundaries, in addition to any scotomas, including blind spots. This movement can be automated, semiautomated, or manual.
Static automated threshold perimetry a refers to the projection of a white stimulus onto a white background to determine the probable threshold at chosen locations in the visual field. Blue on yellow static automated threshold perimetry is also available.
Automated kinetic perimetry b uses a moving stimulus of a selected size and intensity, with the speed and direction of the stimulus being automated.
It is in this context that the Social Security Administration (SSA) must determine whether applicants with visual field loss qualify for benefits under one of the agency’s disability programs. As part of its disability determination process, SSA considers whether an applicant would qualify for disability benefits on the basis of criteria specified in its Listing of Impairments—specifically those in the Special Senses and Speech Listings for both adults and children, which include criteria requiring the use of specific types of perimetry and perimeters. For individuals for whom the required tests are not accessible, it may be difficult or even impossible to be approved for disability benefits.
Optical projection consists of projecting a light stimulus onto a background to present it to the patient’s eye in order to map the visual field.
Frequency doubling technology, used in some perimeters, is based on a flicker illusion, which essentially creates an image that appears double its actual spatial frequency. The stimulus does not move across the field, and the flickering is a proxy for the stimulus intensity used in either static or kinetic perimetry.
Visual acuity is a measure of the sharpness or clarity of vision at a given distance.
Visual field efficiency (SSA definition) is expressed as a percentage corresponding to the visual field in the better eye, calculated by adding the number of degrees seen along the eight principal meridians found on a visual field chart and dividing by 5.
Mean deviation is the average difference in visual field sensitivity across all measured locations compared with a normal, age-matched reference field.
Statutory blindness refers to blindness as defined in the Social Security Act: (1) “central visual acuity of 20/200 or less in the better eye with the use of a correcting lens” or (2) “an eye that has a visual field limitation such that the widest diameter of the visual field subtends an angle no greater than 20 degrees” (Social Security Act, sections 216[i][1]; 1614[a][2]).
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a Multiple terms are used to refer to the same technology. This report preferentially uses the term static automated threshold perimetry to distinguish it from other types of perimetry (e.g., kinetic, manual, suprathreshold).
b Although automated (or automatic) kinetic perimetry is typically used in the literature, this report preferentially uses the term semiautomated kinetic perimetry to be more precise about the role of the technician in administering the test.
STUDY CHARGE AND SCOPE
In August 2024, SSA requested that the Health and Medicine Division of the National Academies of Sciences, Engineering, and Medicine convene an ad hoc committee of relevant experts2 to review the latest published research and science on visual perimetry devices. The committee
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2 The committee included experts in ophthalmology (adult and pediatric), neuro-ophthalmology, optometry, optical science, internal medicine, measurement validation, and SSA disability policy.
BOX S-2
Statement of Task
The task order objectives for the ad hoc committee of the National Academies of Sciences, Engineering, and Medicine are to review the latest published research and science and produce a report addressing best practices and known limitations in the use of visual perimeter devices to measure visual field loss in connection with disability evaluations, including
- Describing the current practice landscape for the measurement of visual field impairment with visual perimeter devices, and recent changes or challenges in the provision of such care; and
- Answering the following questions based on published evidence (to the extent possible) and professional judgment (where published evidence is lacking):
- Is optical projection of the testing stimuli still a necessity to achieve valid and reliable results from a perimeter? How does the eye respond differently to projected stimulus vs. other types (e.g., LCD screens)?
- Do perimeters using frequency doubling technology produce substantially similar results to traditional perimeters and what differences are there?
was charged with producing a report addressing best practices and known limitations in the use of visual perimeter devices to measure visual field loss in connection with SSA’s disability evaluations. This review was to include identifying the latest standards of care regarding measurement of an individual’s visual fields. The committee also was asked to review the devices, techniques, and standards used by other federal agencies to make determinations of statutory blindness based on visual field loss. The committee’s work was to be based on published evidence (to the extent possible) and professional judgment (where such evidence is lacking). Box S-2 contains the committee’s full statement of task. SSA requested that the committee’s report include conclusions, but not recommendations.
STUDY APPROACH
The committee met four times to discuss the questions posed in the statement of task and held a public information-gathering session to hear from invited speakers about disparities and opportunities in access to vision testing, lived experiences with visual impairment and applying for
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- Is automatic kinetic perimetry a valid and reliable method of measuring visual field loss? What are the necessary device specifications and testing circumstances for automatic kinetic perimetry to produce valid and reliable visual field testing?
- What are the most widely acceptable and commonly used alternatives to kinetic perimetry, both manual and automated, for the measurement of visual field efficiency? What impacts do such alternative methods have on the validity and reliability of testing results?
- From a medical and practical perspective, is it still necessary for SSA to require three published clinical validation studies to find a perimeter acceptable or could fewer studies potentially show validity with similar reliability? If fewer validation studies could be acceptable, would there be higher requirements on the design or execution of those studies?
- What devices, techniques, and standards are other federal agencies using to make statutory blindness determinations based on visual field loss?
The report will include findings and conclusions but not recommendations.
SSA disability benefits, and emerging technologies in visual field testing. These speakers informed the committee’s understanding of challenges in providing care for visual field impairment and how such impairment can affect employment, day-to-day life, and general well-being.
After discussing each item in the statement of task, the committee reached consensus on its conclusions, which reflect the published evidence and the committee members’ professional judgment where published evidence is lacking. Additionally, National Academies staff conducted a broad scoping search of perimetry validation studies published since 2002. This review supported the committee’s discussion of the essential elements of an effective perimetry validation study while helping to ensure that the standards discussed were achievable.
THE COMMITTEE’S CONCLUSIONS
The committee formulated 17 conclusions about visual field testing in the following areas: (1) visual field testing in federal agencies, (2) current and emerging practice in visual field testing, (3) evaluating new perimetry
techniques, and (4) special topics in visual field testing. (Note that the numbering of the conclusions here is the same as that in the report chapters [e.g., Conclusion 2-1 is found in Chapter 2 of the report]).
Visual Field Testing in Federal Agencies
As mentioned, SSA specifies requirements for visual field testing to inform its disability determinations. These requirements clarify when and how different methods, such as static automated threshold perimetry and manual or semiautomated kinetic perimetry, are to be used, ensuring that test results align with SSA’s standards. Like SSA, many other government agencies have their own definitions of disability and visual impairment and their accepted methods for assessing visual field loss. Those assessments are used to determine eligibility for disability benefits, eligibility for other disability-related programs, or qualification for certain jobs. Most go beyond the federal definition of statutory blindness, which requires that the widest diameter of a person’s visual field be 20 degrees or less. Some agencies, like SSA, use statutory blindness as one of several medical criteria for a person to qualify as disabled. Others adopt a functional definition of visual impairment that is based on potential obstacles to engaging in relevant daily tasks. Most, however, set a specific visual field size that examinees must meet or not meet. The preferred perimeters and measurement techniques also differ among agencies, with some permitting a broader selection than others.
Some agencies use visual field assessment to determine eligibility for employment in jobs requiring good vision. The varying requirements in occupationally based visual assessment suggest that the bar for meaningful visual impairment is vocation specific. Other federal programs define visual impairment or disability based on functional criteria rather than specific diagnostic measures, emphasizing the impact on activities such as education or daily living. Federal programs designed to promote equality of access to, for example, education similarly define eligibility using functional criteria, such as a person’s inability to access standard educational materials, verified by qualified experts. This approach highlights the emphasis on functional impact over the type of objective medical criteria found in federal disability evaluations.
Based on its review of the literature, the committee reached the following conclusion:
Conclusion 2.1: Different federal government agencies have their own definitions of disability and visual impairment and their accepted methods for assessing visual field loss for a variety of purposes, including determining eligibility for disability benefits, eligibility for other disability-related programs, or qualification for certain jobs.
Current and Emerging Practice in Visual Field Testing
Perimetry is an essential diagnostic tool for assessing a variety of ophthalmic conditions. As noted previously, perimetry techniques consist of a combination of hardware, stimuli (e.g., luminance, size), testing patterns, and algorithms. Static automated threshold perimetry measures the sensitivity of an individual’s visual fields at specific test locations and has the capability to compare the findings with a normal database of previously tested patients. Specific programs can be used to tailor the test to focus on the visual field loss of the patient. Manual or semiautomated kinetic perimetry may also be used by eye care providers to assess visual fields. However, semiautomated techniques are used more commonly than manual ones because of the need for trained personnel to conduct the latter and because of the ability to standardize testing conditions with the former.
Recent changes in practice include newer algorithms that reduce the number of stimuli presented to the patient and quickly learn which additional points should be tested based on previous responses. The shorter testing times made possible by these algorithms decrease reliability, although not significantly. Testing algorithms are not mentioned in the SSA listings, but they are important, as test performance is algorithm specific. Moreover, as visual field loss worsens, variability in performance increases. In other words, for individuals who are sufficiently impaired to be categorized as disabled, variability in test results will increase. Given the learning curve in visual field testing, conducting multiple tests might improve the accuracy of the results. It is unclear how many visual field tests might be required to achieve optimum accuracy, but administering a minimum of two tests may improve results, particularly in patients naïve to visual field tests.
SSA’s listing criteria for assessing mean deviation requires a Humphrey Field Analyzer 30-2 test result. The committee notes, however, that the 30-2 testing pattern is used less often now in routine practice and that the 30-2 and 24-2 test patterns are functionally equivalent in many instances. Manual and semiautomated kinetic perimetry also are not needed except for special circumstances, such as for SSA’s calculation of visual field efficiency.
Based on its review of the literature, the committee reached the following conclusions:
Conclusion 3.1: Measurement of visual field impairment involves components beyond the hardware or visual perimetry device, including stimuli, testing patterns, and algorithms. All components are important to consider when evaluating the validity of visual field assessment.
Conclusion 3.2: Because variability in the results of visual field assessment increases as the severity of visual field impairment increases, and given the learning curve in visual field testing, more than one visual field
test may be needed to characterize an individual’s visual field impairment accurately.
Conclusion 3.3: The Social Security Administration’s listing criteria for assessing mean deviation require a Humphrey Field Analyzer 30-2 test result, but this testing pattern is used less often now in routine practice. In many instances, however, the 24-2 testing pattern is functionally equivalent to the 30-2 testing pattern and may be sufficient for assessing mean deviation.
Perimetry outcomes can vary as a result of patient-related factors, differences in perimeters and how perimetry is performed, and systems-level factors. Patient-related factors include whether a patient possesses the mental and physical capacity to participate in the testing, the patient’s previous experience with perimetric testing, their use of alcohol and medications that may suppress the central nervous system, the presence of diseases such as diabetes or arthritis, the patient’s level of fatigue, and ocular conditions that may affect the ability to fixate. Perimetry results can also vary depending on choices made by examiners, including the type of perimeter used, the order in which the left and right eyes are tested, and whether patients are supervised and well positioned during the testing. With respect to systems-level factors, visual field testing using traditional perimeters such as the Humphrey Field Analyzer (static automated) and Octopus (semiautomated kinetic) requires oversight by experienced technicians, creating challenges for individuals with limited access to appropriately trained eye care providers. Expanding vision care to settings such as primary care, health clinics, and federally qualified health centers can improve access. Emerging cost-effective technologies, such as virtual reality headsets and tablet- and desktop-based systems, also show promise for improving accessibility. Virtual reality headsets offer high-resolution stimuli and built-in eye tracking, which can provide an accurate measure of fixation stability and thus improve test reliability. Tablets and desktop systems leverage widely available devices to facilitate home testing, but they face challenges that can impact reliability, such as uncontrolled lighting, inconsistent viewing angles, and reduced standardization of test conditions.
Based on its review of the literature, the committee reached the following conclusion:
Conclusion 3.4: Visual field testing with traditional perimeters such as the Humphrey Field Analyzer and Octopus requires oversight by experienced technicians who may be in limited supply, creating challenges for some populations with limited access to care. Emerging cost-effective technologies, such as virtual reality headsets and tablet- and
desktop-based systems, show promise for improving accessibility. With proper design and implementation, these tools may significantly expand access to visual field testing while maintaining reliability and validity, assuming studies demonstrate the ability to provide accurate, reproducible results even in an unsupervised setting and their suitability for determining SSA disability in the target population.
Evaluating New Perimetry Techniques
Validating a new perimetry technique requires a thorough assessment of its validity, reliability indices, and reproducibility, all aligned with its intended use in SSA disability determination. The ideal study assessing a new perimetry technique is designed so that it directly evaluates the technique’s intended use and target population—for this report, specifically to determine whether an individual meets the criteria for visual field loss in connection with SSA disability determination. Given that the committee’s review of the literature revealed no studies that directly examined a perimetry technique for this specific purpose, one could use correlation between the results obtained with a new technique and those obtained with a reference standard perimeter in eyes with moderate and/or severe functional loss as a proxy. As reference standards are typically the current “gold standard,” comparing new perimeters to the Humphrey Field Analyzer using a size III stimulus may generate useful evidence.
Determination of the acceptability of a perimetry technique needs to focus on its specific combination of testing algorithm, stimuli, and device rather than being based solely on the device itself. Also essential is to take the scope of evidence into account, including data from diverse populations and real-world settings, to ensure that the technique performs effectively across patients with various underlying clinical conditions. Risk of bias assessment is also important.
Based on its review of the literature and the committee’s expert assessment, the committee reached the following conclusions:
Conclusion 4.1: When assessing the acceptability of a technique for visual field assessment, the quality, relevance, and totality of the evidence are more important than the number of published studies available.
Conclusion 4.2: Sensitivity (in the sense of a test’s ability to identify correctly those with a qualifying disability) and specificity (a test’s capacity to identify correctly those without a qualifying disability) are important metrics for assessing a test’s internal validity. Both specificity and sensitivity need to be measured with sufficient precision to permit confident evaluation against the SSA criteria.
Many perimeters report statistics such as fixation losses and false-positive and false-negative results. While these reliability indices provide useful information about how a perimetry test was conducted, it is not always appropriate to treat them as fixed binary cutoffs. Instead, it is important to examine a test result that appears to have poor reliability to determine why poor reliability indices were measured and whether there is sufficient information for the assessment of disability.
Based on its review of the literature, the committee reached the following conclusion:
Conclusion 4.3: Test results that appear to have poor reliability indices need to be examined to determine whether the results may still be useful for identifying deficits that qualify for disability benefits by providing sufficient information for the determination of disability.
With intensities above 15–20 decibels (dB) on a Humphrey Field Analyzer perimeter or the equivalent on other instruments, the probability of an examinee responding to the stimulus plateaus. Therefore, further increases in brightness (decrease in dBs) have minimal impact on detectability, hindering accurate measurement of severe field loss. Variability in results may also arise from different levels of contrast. Research has shown that testing with contrasts greater than 15–20 dB does not enhance the ability to detect disease progression and can be excluded without loss of information.
Based on its review of the literature and the committee’s expert assessment, the committee reached the following conclusion:
Conclusion 4.4: Although SSA’s current criteria for visual disability require the ability to detect a stimulus corresponding to 10-dB contrast on a Humphrey Field Analyzer perimeter, it is likely that equivalent results can be achieved using a stimulus corresponding to a 15-dB contrast.
Special Topics in Visual Field Testing
Optical Projection Versus Screen-Based Stimuli
A strong and growing body of literature suggests the acceptable clinical performance of perimeters that do not use optical stimulus projection. While theoretically, the perception of projected and nonprojected stimuli that are otherwise similar should be the same, scientific evidence specifically evaluating the consistency of test results using different types of stimuli is limited.
Screen-based perimeters may become more acceptable and reliable for the average patient, as they are both cheaper than traditional perimeters
and based on common consumer electronics. Virtual reality perimeters, in particular, may be able to include eye tracking and adjust for fixation, which would make them far more reliable than traditional techniques. As these technologies develop, allowing their use for SSA disability determination would make perimetry easier, more available, and less costly for more people.
At present, however, these new technologies come with substantial uncertainties in performance. Luminance varies significantly among different screen-based perimeters, and stimuli may not be exactly the same as in traditional perimeters because of limitations in modern screen-based technology. Many screen-based perimeters are also not able to achieve the range of luminance (especially at the dim end) that is achieved in table-top perimeters.
Device manufacturers can mitigate these challenges in a variety of ways, such as by modifying the stimulus intensity, size, and duration. Different test patterns may also be feasible in the future. In theory, variations in these design factors could result in stimuli functionally equivalent to those presented by traditional perimeters. To best validate these perimeters for use in SSA disability determination, their performance in relevant classification tasks should be compared with that of currently accepted projection-based methods.
Based on its review of this evidence and the committee’s expert assessment, the committee reached the following conclusions:
Conclusion 5.1: The technology used to present stimuli and backgrounds during perimetry, such as optical projection or video screens, is unlikely to have a substantial effect on visual perception or test results. However, because perimeters using nonprojected visuals have been developed only relatively recently, evaluation studies of such perimeters will be most useful if they robustly report specific testing parameters and the technical details of the device.
Conclusion 5.2: The suitability of novel perimeters for SSA’s use in disability determination is affected by their performance relative to that of current methods; comparative validation studies, ideally using SSA-relevant classification tasks, will therefore be the best way to assess suitability.
Frequency Doubling Technology
Frequency doubling technology (FDT) is a specialized visual field–testing method that uses high-frequency flickering stimuli to assess the integrity of the visual field. It is typically used as a screening test, especially for early
or mild visual field impairment caused by glaucoma. Perimeters using FDT tend to be less expensive and easier to use than static automated threshold perimeters for both clinicians and examinees, and they tend to yield similar results in patients with early or mild glaucomatous impairment. Although results across studies regarding its sensitivity, specificity, and agreement of its results with those of static automated threshold perimetry are mixed, the differences are greatest in cases of severe impairment. FDT also gives very poor results in patients with cataracts, making it difficult to interpret results and potentially leading to results that may not reflect a true defect. Ultimately, more studies aimed at validating the use of FDT for diagnostic tasks such as those performed by SSA will be the most useful research.
Based on its review of the literature and the committee’s expert assessment, the committee reached the following conclusions:
Conclusion 5.3: Second-generation frequency doubling technology (FDT2) devices have demonstrated similarity to traditional perimeters in the measurement of visual field contrast sensitivity; however, most studies thus far have been conducted in individuals with mild to moderate visual impairment. Additional studies are needed to determine the suitability of these devices for assessing visual function in individuals with severe visual impairment.
Conclusion 5.4: Because of its portability and lower cost, frequency doubling technology is likely to be particularly useful in settings where patients have limited access to static automated threshold perimetry and other traditional perimeters.
Semiautomated Kinetic Perimetry
Semiautomated kinetic perimetry can be used to determine disability as defined by SSA; it can identify peripheral visual defects outside the central 30 degrees, a requirement for calculating visual field efficiency as defined by SSA. In addition, semiautomated kinetic perimetry adds value over manual kinetic perimetry because it requires less of a learning curve and operators require less technical expertise and training.
At the same time, kinetic perimetry (either manual or semiautomated) has limitations. First, the results of kinetic perimetry tend to be less concordant with those of static automated threshold perimetry methods when used to assess the central visual field; therefore, kinetic perimetry is more often used at the periphery. Moreover, to realize the full potential of kinetic perimetry for full-field and peripheral visual field assessment, an examiner needs experience and training beyond that required by static perimetry. A skilled technician can monitor for fixation loss, check for false negatives
or positives, and plot more complicated scotomas. In particular, ineffective monitoring of fixation can lead to overestimation of visual field performance. As a result, static automated threshold perimetry may be preferred if the patient presents with generalized constriction of the visual field and neither peripheral “islands of vision” nor ring scotomas are likely. Static automated threshold perimetry uses standardized algorithms to plot threshold contrast sensitivities automatically within the central 48–60 degrees of the visual field.
In addition, acquiring an Octopus perimeter (the most common platform capable of performing semiautomated kinetic testing) may be prohibitively expensive, and even where these devices are available, technicians adequately trained to use them may not be available. If Octopus perimeters were the only machines SSA considered acceptable for employing semiautomated kinetic strategies, then given the associated cost and training constraints, permitting semiautomated kinetic perimetry might yield only modest improvements in the availability of visual field testing. On the other hand, some clinics may have only an Octopus or other semiautomated kinetic perimeter, or an individual clinician may prefer using this form of perimetry.
Based on its review of the literature, the committee reached the following conclusion:
Conclusion 5.5: When administered by a skilled technician, semiautomated kinetic perimetry has sufficient accuracy in quantifying visual field efficiency for use by SSA in disability determinations.
Alternatives to Kinetic Perimetry for Visual Field Efficiency
While static automated threshold perimetry is available to measure peripheral vision, it may not suffice for measuring the full extent of the visual field, as required by SSA for the calculation of visual field efficiency. For most people seeking disability benefits, however, this limitation does not make much of a difference; a person found to qualify for disability benefits using a 60-degree perimeter likely would have a sufficiently constrained visual field to qualify and would not need additional testing with a perimeter to test further boundaries. Furthermore, static automated threshold perimetry is currently far more commonly available than semiautomated kinetic perimetry, and it can be performed with more consistency and less examiner bias than manual kinetic perimetry.
Allowing the use of static automated threshold perimetry for assessing visual field efficiency may yield uncertain or inadequate results in some scenarios. Since all of the current commercially available instruments and testing methods have their own limitations with respect to the clinical
information they provide, multiple tests with the same method or an array of methods may be required to provide a better understanding of the extent of visual field loss. For example, kinetic perimetry could be used to measure at the peripheral field, while static automated threshold perimetry could be used centrally.
Although static automated threshold perimetry is not a “one-to-one” substitution for kinetic perimetry, it usually can provide the data required to calculate visual field efficiency. However, there may be rare exceptions. It is theoretically possible that a ring scotoma, such as those seen in retinitis pigmentosa, could leave the entire visual field past 60 degrees unaffected. Using static automated threshold perimetry for measurement of visual field efficiency in such a person could yield a technical “false positive” that would result in approving that person for disability benefits. However, the committee believes that the overall disability experienced by such an individual with significant ring scotomas or midperipheral visual field loss is otherwise likely to provide sufficient evidence to result in a disability determination.
Use of a larger stimulus size can increase the reliability of static automated threshold perimetry at the periphery. The currently mandated size III Goldmann stimulus has resulted in increased intertest variability and lower sensitivity, especially at the periphery. A size V stimulus would be more feasible and reliable if static automated threshold perimetry were to be used to assess visual field efficiency.
Based on its review of the literature, the committee reached the following conclusions:
Conclusion 5.6: Despite the limitations of static automated threshold perimetry (SAP) in measuring peripheral field loss, this method can usually provide the data necessary to calculate the visual field efficiency of an applicant for SSA disability benefits.
- Visual field efficiencies calculated using SAP will generally be diagnostically equivalent to those calculated using currently approved manual (Goldmann) kinetic or semiautomated kinetic perimetry; applicants who qualify for benefits using one will almost always qualify using the other.
- Even in exceedingly rare scenarios in which a person qualifies for disability benefits based on SAP assessment of visual field efficiency whereas in fact, the regions of the peripheral visual field outside the region mapped by SAP have preserved vision to a degree that the true visual field efficiency would not meet SSA requirements, the overall disability experienced by the applicant is likely to provide sufficient evidence to result in a disability determination.
Conclusion 5.7: The use of larger stimuli, further diagnostic tests, and other clinical data can improve the diagnostic reliability of static automated threshold perimetry for the calculation of visual field efficiency.
Pediatric Considerations
Given the practical considerations involved in evaluating visual field in children across a range of ages and developmental statuses, there is particular value in increased flexibility in perimetry requirements for the pediatric population. Additionally, newer technologies have the potential to address challenges associated with performing perimetric examinations in children. For example, virtual reality–based platforms may be more comfortable for children, and they can include design features such as incorporation of game-like features and eye tracking to make the test more effective. Oculokinetic perimetry is another option for measuring visual field, especially in young children.
In contrast to adults with visual impairment, many children with visual impairment severe enough to qualify for SSA disability benefits have other comorbid health conditions. In evaluating perimetry for determining visual disability in children, it is important to allow flexibility in the requirement for formal visual field testing in children who are unable to comply with this requirement because of their developmental or health status.
Based on its review of the literature, the committee reached the following conclusion:
Conclusion 5.8: There is particular value in increased flexibility in perimetry requirements for children, given the practical considerations involved in evaluating visual field in this population across a range of ages and developmental and health statuses. Newer technologies, such as screen-based perimeters using perimetry methods that incorporate game-like features or oculokinetic perimetry, have the potential to address these challenges in pediatric perimetry and yield valid information for the identification of SSA-qualifying visual field loss.
