Optical Coherence Tomography Angiographic Changes before Development of Exudative Age-related Macular Degeneration in Eyes with Non-exudative Neovascularization

Abstract

Purpose :
To determine the incidence of fellow eye involvement in patients presenting with unilateral typical Age related macular degeneration (tAMD) or polypoidal choroidal vasculopathy (PCV) and to evaluate the patterns of Optical Coherence Tomography Angiography (OCT-A) changes before the onset of exudative change, especially focusing on non-exudative neovascularization.

Methods : Data for this study was taken from a prospective, observational cohort study involving Asian patients with exudative AMD in the Asian AMD Phenotyping Study. Patients presenting with unilateral exudative AMD were included. The contralateral eye was evaluated for presence of non-exudative neovascularization based on multimodal imaging which included ICGA, spectral domain optical coherence tomography (SD-OCT) and OCT-A.
The difference between the incidence of those with non-exudative CNV and those without was analyzed using Log-rank test and qualitative analysis of OCT-A images.
Main outcome measures: The difference between the incidence of those with non-exudative CNV and those without as analyzed using Log-rank test and qualitative analysis of OCT-A images.

Results : We included 95 fellow eyes of 95 patients who presented with unilateral exudative AMD. Non-exudative neovascularization was present in 19% eyes [8 (22.9%) and 10 (19.0%) fellow eyes with tAMD and PCV, respectively, 8 on OCT-A, 5 on ICG-A and 5 on both OCT-A and ICGA]. Development of exudative change was noted in 6 fellow eyes (6.3%). Four eyes developed exudation from previously noted non-exudative neovascularization and 2 eyes arose exudative change from de novo. The period between diagnosis and fellow eye involvement was shorter in eyes with non-exudative neovascularization than those without (P = 0.0083, Log Rank test). In all eyes whose OCT-A images were available immediately before the onset of exudative change, there was an increase in the size of network vessels compared to baseline.

Conclusions : The presence of non-exudative neovascularization significantly predisposes to the development of exudative change, supporting the importance of monitoring non-exudative neovascularization with multimodal imaging including OCT-A and ICGA.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.