Abstract
PURPOSE: To assess glaucoma specialists' detection of optic nerve head (ONH) rim tissue that is thin by optical coherence tomography (OCT) criteria. DESIGN: Reliability analysis. METHODS: Five clinicians marked the disc margin (DM) and rim margin (RM) on stereophotographs of 151 glaucoma or glaucoma suspect eyes obtained within 3 months of OCT imaging. The photo and OCT infrared image for each eye were co-localized and regionalized into 12 sectors relative to the axis between the Bruch membrane opening (BMO) centroid and the fovea. For each clinician, the distance from BMO centroid to their DM (DM radius) and RM (RM radius) was used to generate sectoral rim width (RW) (DM radius-RM radius) and cup-to-disc ratio (CDR) (RM radius/DM radius) estimates. OCT minimum rim width (MRW) was determined by sector. Among all eyes, for each OCT MRW suspicious sector (<5% of OCT normative database), we determined each clinician's detection (clinician CDR ≥ 0.7). RESULTS: Clinicians most commonly failed to detect OCT suspicious rim tissue in the nasal sectors. Among 502 sectors with suspicious OCT MRW, all 5 clinicians rated CDR ≥ 0.7 in only 29.5% and all 5 clinicians rated CDR < 0.7 in 21%. OCT suspicious rim thickness was most common (32% of eyes) in the nasal and inferior sectors. MRW vs clinician RW discordance was greatest nasally, while BMO vs clinician DM discordance was greatest temporally. CONCLUSIONS: Clinicians most commonly failed to detect OCT suspicious rim thickness nasally where suspicious rim tissues were also most common.