In patients with early visual field damage, the 24-2 Humphrey Field Analyzer test is sufficient to diagnose progression of open-angle glaucoma. According to findings published in Ophthalmology, the addition of a 10-2 test is only prudent for following patients who have a higher perceived risk for glaucoma in the central visual field.
The investigators of this prospective longitudinal study sought to assess whether the 10-2 Humphrey Field Analyzer test could detect a higher proportion of abnormal visual fields compared with the conventional 24-2 test in patients with early visual field damage.
The study included 97 individuals with early open-angle glaucoma and 65 healthy controls. All participants underwent both a 24-2 and 10-2 test every 4 months; only 1 eye was analyzed for each participant. To compare equivalent visual field areas, only the 12 test locations of the 24-2 program that correspond to the central 10 degrees of the visual field were included in the final analysis. The primary study outcome was overall performance of the 2 tests across 4 pointwise criteria: investigators performed both total deviation and pattern deviation analyses for test locations at the 5% and 2% probability levels. For each criterion, overlap for the 24-2 and 10-2 tests were reported for patients who were correctly identified with glaucoma. Finally, repeatability of abnormal results for both tests, 1 test, or neither test was determined in 2 follow-up visual field examinations.
For the 4 criteria, the area under the receiver operating characteristic curve ranged from 0.88 to 0.93 in the 24-2 test and 0.91 to 0.94 in the 10-2 test; although the 10-2 test area under the receiver operating characteristic curve for all analyses were slightly higher than the 24-2 test, the difference was not significant. However, sensitivity of the 24-2 test across all criteria was higher than the 10-2 test and was significant in all but the pattern deviation analysis at 5%. Overlap in patients with glaucoma as identified in both test programs was higher in total deviation analysis vs pattern deviation analysis; similarly, overlap was higher at the 5% probability level vs the 2% probability level. The greatest overlap was reported for total deviation analysis at the 5% level, which found abnormal results in 90% of participants in either the 24-2 or 10-2 test and 86% with abnormal results in both tests. The least amount of overlap was reported for pattern deviation analysis at the 2% level, in which 75% of participants had abnormal results for either test, and 60% had abnormal results in both tests. Spatial concordance of visual field defects was performed by quadrant for both total deviation and pattern deviation analyses at the 5% probability level. Total deviation analysis results ranged from 70% (inferior temporal quadrant) to 87% (superior temporal quadrant), and pattern deviation analysis results ranged from 74% (inferior nasal quadrant) to 87% (superior temporal quadrant). Over the follow-up period, test results were repeatable in 55% (pattern deviation analysis) to 70% (total deviation analysis) of patients with glaucoma.
Limitations of the study include the retrospective nature and not having a true independent reference standard for glaucoma, which may result in selection bias.
The authors suggest that they found little evidence that adding the 10-2 test could detect additional defects over the conventional 24-2 test in patients with early glaucoma. They added that the 10-2 test should be reserved for follow-up in select patients who demonstrate higher risk for disease progression in the central visual field.
Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
West ME, Sharpe GP, Hutchinson DM, et al. Utility of 10-2 visual field testing in glaucoma patients with early 24-2 visual field loss. Ophthalmol. [published online September 6, 2020]. doi: 10.1016/j.ophtha.2020.08.033