Detecting progression in advanced glaucoma using macular and circumpapillary optical coherence tomography summary metrics

Abstract

Purpose : To test the hypothesis that macular ganglion cell metrics are more effective than circumpapillary metrics for detecting disease progression in eyes with advanced glaucoma.[1,2]

Methods : 32 eyes of 28 patients (66±15.1 yrs, range: 22 to 83 yrs) had a mean deviation (MD)≤-12 dB on a 24-2 visual field (VF). All eyes had at least 2 spectral domain (SD) optical coherence tomography (OCT) imaging sessions, 0.8 to 3.3 yrs apart, with 3.5mm circle scans of the disc placed in the same location by the commercial software and 30°x25° cube scans that included the macula. Progression was assessed with summary metrics including global and sectoral cpRNFL thicknesses, as well as global and hemi-macular ganglion cell layer (GCL), GCL plus inner plexiform layer (+) and GC complex (GCC) thicknesses (Table). The group results were analyzed with linear mixed model regression. Additionally, for a progression reference standard (RS), 3 experts evaluated each eye for progression using a custom one-page report, circle scans of the disc, and 24-2 and 10-2 visual fields.

Results : According to the group analysis, only the global cpRNFL metric showed significant change between visits (Table). None of the macular metrics showed significant change; due in part to the development of epiretinal membranes and/or poor segmentation as identified by post-hoc analysis of the b-scans. According to an analysis of individual eyes based upon a 5% one-tail cutoff (red line in Fig), none of the metrics did well. Only 3 of the eyes significantly progressed based on the global cpRNFL, while 2 of these 3 eyes also progressed based on the global and superior GCC metrics. According to the RS, 14 of the 32 eyes progressed, and the metrics missed 11 of these.

Conclusions : The relatively poor performance of the cpRNFL and macular metrics highlights the importance of careful inspection of the b-scan in order to use OCT for monitoring progression in eyes with advanced glaucoma.[3] 1. Lavinsky F et al. Ophthalmol. 2018; 2. Belghith A et al. IOVS. 2016; 3. Lee et al. Ophthalmol. Glaucoma. 2019

This is a 2020 ARVO Annual Meeting abstract.