Detecting glaucoma progression using optic nerve volume scans with three-dimensional spectral-domain optical coherence tomography

Abstract

Purpose : To determine whether three-dimensional (3D) spectral-domain optical coherence tomography (SD-OCT) neuroretinal rim measurements detect glaucoma progression earlier than current standard of care clinical testing i.e., disc photography (DP), visual field (VF) testing, and two-dimensional (2D) retinal nerve fiber layer (RNFL) thickness measurements.

Methods : In this 5-year prospective longitudinal cohort study, 124 eyes of 124 open angle glaucoma patients had yearly DP, VFs, SD-OCT RNFL thickness scans, and optic nerve volume scans (Spectralis, Heidelberg Engineering, Heidelberg, Germany) which were performed on the same day. From high-density optic nerve volume scans, custom-built software calculated the minimum distance band (MDB) thickness, a 3D neuroretinal rim parameter, which quantifies the amount of tissue in the neuroretinal rim. Patients were classified as glaucoma progressors or non-glaucoma progressors using event-based analysis. Progression by DP and VF were determined when 3 masked glaucoma specialists unanimously concurred. Progression by RNFL and MDB thickness were determined if there was change greater than test-retest variability. Kaplan-Meier curves were constructed to analyze time-to-progression data.

Results : Global MDB neuroretinal rim thickness detected glaucoma progression earlier either DP (23 versus 44 months; P<0.001) or global RNFL thickness (23 versus 33 months; P<0.001). Global MDB thickness also detected progression slightly earlier than visual fields (23 versus 32 months), but the difference was not statistically significant (P=0.15).

Conclusions : High-density 3D SD-OCT neuroretinal rim measurements detected glaucoma progression approximately 1-2 years earlier compared to current clinically available structural tests (i.e., DP and 2D RNFL thickness measurements).

This is a 2021 ARVO Annual Meeting abstract.

 

Comparison of event-based progression analysis using Kaplan-Meier curves for visual field (VF) testing, global two-dimensional (2D) retinal nerve fiber layer (RNFL) thickness, global three-dimensional (3D) neuroretinal rim thickness, and disc photography (DP). The global 3D neuroretinal rim thickness detected glaucoma progression significantly earlier than current clinically available structural tests [i.e. global RNFL thickness and DP (P<0.001)].