Comparison of Structural, Functional, Tonometric, and Visual Acuity Testing for Glaucoma

Purpose To determine the diagnostic accuracy of potential screening tests for moderate to advanced glaucoma. Design Prospective diagnostic test accuracy study. Participants The study enrolled a consecutive series of patients aged ≥50 years who presented to a glaucoma clinic in South India without ever having received automated visual field testing. Methods All participants underwent 8 index tests: OCT of the peripapillary retinal nerve fiber layer, optic disc photography, Moorfield’s Motion Displacement Test (MDT), frequency doubling technique perimetry, noncontact tonometry, pneumatonometry, presenting visual acuity, and best-corrected visual acuity. Participants also underwent stereoscopic photographs and Humphrey visual fields, which were used by 2 ophthalmologists to arrive at the reference standard diagnosis of moderate to advanced glaucoma. Main Outcome Measures Sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio. Results A total of 217 people were enrolled; 321 eyes from 180 participants had all tests performed. Of these, 127 eyes (40%) were classified as having moderate to advanced glaucoma. Among the 8 tests, OCT best optimized sensitivity (84%, 95% confidence interval [CI], 76–90) and specificity (75%, 95% CI, 68–81). Moorfield’s Motion Displacement Test was the best perimetric test, with a sensitivity of 91% (95% CI, 85–96) and specificity of 53% (95% CI, 44–61). Pressure and vision tests were not sensitive (e.g., sensitivity of 16%, 95% CI, 9–23 for noncontact tonometry and 23%, 95% CI, 15–31 for best-corrected visual acuity). Moorfield’s Motion Displacement Test identified 16 of 127 eyes (13%) with glaucoma that were not captured by OCT, but also had false-positive results in 65 of 194 eyes (34%) without glaucoma that OCT correctly classified as negative. Conclusions OCT had moderate sensitivity and fair specificity for diagnosing moderate to advanced glaucoma and should be prioritized during an initial assessment for glaucoma.