Choroidal Changes in Eyes with Exudative AMD Before and After Anti-VEGF Therapy Imaged with Swept-Source OCT

Abstract

Purpose : Swept-source optical coherence tomography (SS-OCT) was used to investigate choroidal changes after anti-vascular endothelial growth factor (anti-VEGF) therapy in eyes with exudative age-related macular degeneration (eAMD) that contained three types of macular neovascularization (MNV).

Methods : Treatment-naïve eyes with eAMD undergoing anti-VEGF therapy were included. SS-OCTA images (PLEX® Elite 9000; Carl Zeiss Meditec, Inc, Dublin, CA) were obtained at the first treatment and after anti-VEGF injections. Mean choroidal thickness (MCT) and choroidal vascularity index (CVI) measurements in both 5mm and 11mm foveal centered circles were obtained from the 12X12mm scans. If the choroidal signal was blocked from overlying retinal pigment epithelial detachments (PEDs) or hemorrhage, then these areas were excluded from the CVI measurements. If more than 10% of the 5mm circle region was blocked, then these eyes were excluded from the CVI analysis.

Results : A total of 41 treatment-naïve eAMD eyes from 37 patients were included: 24 eyes with type 1 MNV, 4 eyes with type 2 MNV, and 13 eyes with type 3 MNV. All eyes had two visits that included the day of the first treatment and the first visit after treatment. Seven eyes were excluded from the CVI analysis. For all eyes, the MCT and CVI decreased in both the 5mm and 11mm circles after treatment (P<0.05) compared with the first treatment visit. In eyes with both type 1 and type 2 MNV, the decrease in the MCT within the 5mm (P<0.05) and 11mm circles (P<0.05) were statistically significant, but in eyes with type 3 MNV, the decrease in the 5mm circle MCT was not significant (P=0.32), while there was a significant decrease in the 11mm circle after treatment (P<0.05).

Conclusions : Due to the decrease in the central MCT observed in eyes with type 1 and type 2 MNV, but not type 3 MNV, we propose that at baseline, the type 1 and type 2 MNV lesions serve as high-volume arteriovenous shunts between the choroidal arterial and venous circulations. Anti-VEGF therapy causes a decrease in exudation and a decrease in flow within the arteriovenous shunt that would exist in any type 1 or type 2 MNV while this type of central choroidal arteriovenous shunt would not exist in the intra-retinal type 3 MNV.

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