Early Rate of Optical Coherence Tomography Angiography Changes is Associated with Normal Tension Glaucoma Progression Risk

Abstract

Purpose : Currently, the causal and temporal relationships between the degeneration in retinal vasculature and glaucoma remain ill-defined. This study evaluated the early rate of changes in optical coherence tomography angiography (OCTA) metrics in a cohort of normal tension glaucoma (NTG) eyes, and their relationships to the subsequent risk of glaucoma progression.

Methods : Three hundred and thirty-four eyes from 167 NTG patients with a follow-up period of ≥24 months were included. A swept-source OCT was used to acquire OCTA images of the peripapillary region with a scan area of 3mm x 3mm centered on the optic disc. An automated customized program was used for quantitative analysis to compute the circumpapillary vessel density (cpVD) after the removal of retinal arterioles and venules from the raw OCTA images. Early longitudinal changes of OCTA metrics from baseline to 1 year were determined for each eye. The relationship between the rate of OCTA metrics decay determined from 3 time points (0, 6, and 12 months) in the first year of follow-up to the subsequent risk of glaucoma progression was evaluated. We further attempted to define cut-off values of rate of OCTA decay in the early follow-up phase that would stratify eyes into high risk of glaucoma progression in the subsequent follow-up period.

Results : Twenty-seven eyes (8.08%) developed visual field deterioration over a mean follow-up period of 35.58 ± 5.56 months. Each 1% elevation of the annual rate of cpVD decay in the first year of follow-up was associated with more than 40% risk of glaucoma progression (RR [CI], Temporal cpVD: 1.46 [1.02-2.09]; Nasal cpVD: 1.64 [1.21-2.21]; Global cpVD: 1.48 [1.09, 2.01]) (Table). The Kaplen-Meier curves illustrate that NTG eyes with faster rates of cpVD decay the were associated with significantly higher risk of glaucoma progression, compared to eyes with slower rates of cpVD decay.

Conclusions : This study demonstrated the significant associations between early changes in cpVD as measured by OCTA and the subsequent risk of NTG progression. The findings provided evidence to support the prognostic value of retinal vasculature analysis and a novel perspective for such interpretation in the clinical settings.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.

 

Quantification of OCTA Capillary Metrics in NTG eyes.