Screening for glaucoma in high-risk populations using optical coherence tomography

Abstract

Objective: To estimate the diagnostic accuracy of Stratus optical coherence tomography (OCT) for glaucoma screening in high-risk populations.

Design: Cross-sectional evaluation of a diagnostic test for screening.

Participants: Three hundred thirty-three community-based volunteer participants with risk factors for glaucoma.

Methods: The optic nerve and peripapillary retinal nerve fiber layer (RNFL) of participants' eyes were scanned using the Stratus OCT. Based on an ophthalmologic examination and frequency doubling perimetry, eyes were classified into 4 categories: normal, possible glaucoma, probable glaucoma, and definitive glaucoma.

Main outcome measures: The sensitivities, specificities, positive and negative likelihood ratios of the RNFL, optic disc parameters, and their combinations were calculated.

Results: The right eyes were retained for analyses. After excluding eyes with missing data or with poor quality scans, the data of 210 right eyes were analyzed. Six eyes had definitive glaucoma. Combining the best performing optic nerve head parameters (cup diameter or cup/disc vertical ratio or cup/disc area ratio) and RNFL parameters (superior average or inferior average or overall average) using AND-logic resulted in a sensitivity of 67% (95% confidence interval [CI], 24%-94%), specificity of 96% (95% CI, 92%-98%), a positive likelihood ratio of 17.08 (95% CI, 7.06-41.4), and a negative likelihood ratio of 0.35 (95% CI, 0.11-1.08).

Conclusions: When adequate quality scans may be obtained, the Stratus has moderate sensitivity and high specificity for definitive glaucoma. Specificity is increased when parameters from both the optic nerve head and RNFL scans are combined.