OCT and OCTA complement glaucoma progression detection

Abstract

Purpose : To examine glaucoma progression detection by trend-based optical coherence tomography (OCT) and OCT angiography (OCTA) analysis.

Methods : Primary open-angle glaucoma (POAG) and glaucoma suspects eyes with at least 2-year and 4-visit of OCT/OCTA imaging were included. Peripapillary capillary density (CD) and retinal nerve fiber layer thickness (RNFL) were obtained from Angiovue 4.5x4.5mm² optic nerve head scans. Progression was defined as a negative slope of OCT/OCTA change in linear regression with a P-value smaller than the 5^th-percentile P-value derived from permutation analyses in a separate subset of healthy eyes. Visual field (VF) progression was assessed on VF mean deviation (MD) using the same method. Inter-instrument agreement on progression detection was compared using kappa(κ) statistics.

Results : From 147 eyes(96 subjects), OCTA and OCT identified 39(27%) and 36(24%) progressors, respectively. OCT and OCTA showed slight agreement (κ=0.16) for progression detection, with 14(10%) eyes categorized as progressors by both (Table 1). Similar results were observed in severity-stratified analyses (κ<0.20). Compared to progressors identified only by OCT, progressors identified only by OCTA had thinner baseline RNFL (71.8[65.7, 77.9] vs. 85.4[79.1, 91.7] µm), worse baseline VF (-5.6[-8.2, -2.9] vs. -2.2[-3.7, -0.8] dB), and thicker CCT (556[541, 570] vs. 526[503, 548] µm) (P<0.05). OCT progressors had faster VF (-0.36[-0.53, -0.19] vs. -0.16[-0.24, -0.09] dB/year; P<0.05) worsening than OCT non-progressors, with no difference in CD worsening rates. While OCTA progressors had faster VF (-0.39[-0.52, -0.25] vs. -0.15[-0.23, -0.07] dB/year; P<0.05) worsening than OCTA non-progressors, with no significant difference in RNFL worsening rates. VF progression was identified in 20(14%) eyes (Table 2). OCT and VF showed fair agreement (κ=0.22), with 10(7%) eyes categorized as progressors by both. OCTA and VF showed slight agreement (κ=0.11), with 8(5%) eyes categorized as progressors by both.

Conclusions : OCTA detected more progressors than OCT, and both detected more progressors than VF. OCT showed stronger agreement with VF than OCTA. Given the limited OCT/OCTA agreement, they may provide complementary information on glaucoma progression. Longer follow-up is needed to confirm the functional association of OCTA changes in glaucoma.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.

 

Agreement of OCT and OCTA on progression detection

 

Agreement of VF with OCT and OCTA on progression detection