Is 10-2 Testing Needed for Early VF Loss?
Ophthalmology, April 2021
The notion that testing the central visual field (VF) may give better diagnostic information than full-field testing begs the question of whether the 10-2 test should be done in addition to, or instead of, the 24-2 test. West et al. compared the ability of these tests to detect ab-normal VFs in patients with early glaucomatous damage. Their analysis, which included just the 12 central locations of 24-2 perimetry to ensure fair comparison, showed little evidence that 10-2 testing could identify damage not detected by 24-2 testing.
This prospective observational study included eyes of patients with open-angle glaucoma (n = 97) and healthy controls (n = 65). The median mean deviation of the 97 glaucomatous eyes was –2.31 dB. All patients underwent 10-2 and 24-2 VF testing. The criteria used to compare test performance were total deviation (TD) and pattern deviation (PD) analyses at the 5% and 2% levels. Also analyzed were two pairs of follow-up tests, each performed four months apart. For equitable comparison of the methods, only the 12 central locations of the 24-2 test were included in the analyses. Main outcomes were area under the receiver operating characteristic curve (AUC), sensitivity at identically matched specificity for each criterion, overlap of abnormal VFs with both tests, and replicability of the findings in two subsequent evaluations.
The AUC comparison revealed no significant difference for any of the specified criteria. The values ranged from 0.91 to 0.94 for the 10-2 test and from 0.88 to 0.93 for the 24-2 test. At matched specificity, the 24-2 test was significantly more sensitive for all criteria except PD at 5%. Among patients with an abnormal field detected by either test, 60% to 86% exhibited the abnormality with both tests. Within each quadrant, concordance was even better (70% to 87%). Reproducibility occurred in more than half the cases. The best repeatability was for TD at the 5% level (70% of patients); the poorest was for PD at 5% (55% of patients).
The authors recognize that 10-2 testing may be a valuable follow-up tool for advanced cases of glaucoma. However, the results of this study suggest that it may be unnecessary in early-stage glaucoma. Yet contradictions abound, and there is evidence that 10-2 tests detect abnormalities missed by 24-2 testing. Some investigators are modifying the 24-2 test to include more test sites in the central VF, but published data are sparse. Given the limited resources of many facilities and the need for frequent reliable testing to effectively monitor progression, the authors suggest reserving the 10-2 test for patients at high risk of progression in the central VF.
The original article can be found here.