10-2 testing offers limited benefits over 24-2 testing in patients with POAG

10-2 testing offers limited benefits over 24-2 testing in patients with POAG


Glaucoma


This prospective study tested whether 10-2 testing was better at detecting abnormal visual fields than 24-2 testing in the central 10 degrees of patients with early glaucomatous visual field changes.

Study design

Researchers administered 10-2 and 24-2 testing to 97 patients with primary open-angle glaucoma (POAG) and 65 healthy controls and analyzed the central 12 test locations of the 24-2 test. They compared total deviation and pattern deviation at 2% and 5%. They also performed 2 pairs of follow-up tests, each performed 4 months apart. Outcome measures were area under the receiver operating characteristic curve (AUC), sensitivity at identically matched specificity for the 4 criteria, overlap of abnormal visual fields for both tests, and repeatability of findings in the follow-up tests.

Outcomes

Median mean deviation was −2.31 in the patients with glaucoma. The AUCs for the 24-2 and 10-2 were not significantly different for any of the 4 criteria. The sensitivity of the 24-2 test was higher for all criteria except for pattern deviation analysis at 5%. Regardless of test type, patients with an abnormal field had overlap between 60% and 86%, depending on the criterion. By quadrant, concordance ranged from 70% to 87%. Test results were repeatable in 55% to 70% of patients.

Limitations

When comparing the tests at equal specificity, the number of abnormal test locations required for an abnormal 24-2 test is limited (range 1–3). The 2 tests can be compared only at relatively high specificity because the receiver operating characteristic curve of the 24-2 test lacks granularity. Since the study inclusion criteria included an abnormal 24-2 test, the fact that 10-2 does not offer diagnostic advantage only applies to individuals with existing defects on 24-2. Last, it is possible that the 12 test locations of the 24-2 test are not precisely comparable with the 10-2 test areas.

Clinical significance

These findings suggest that the addition of 10-2 testing in patients with early visual field loss with 24-2 testing has little additional benefit in identifying additional defects. To maximize resources, it might be better to reserve 10-2 testing for following patients with a higher risk of progression in central visual field.

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