AI-based correlation of functional retinal testing with retinal fluid volumes and compartments in neovascular age-related macular degeneration

Abstract

Purpose : Microperimetry (MP) is emerging as a clinical endpoint in retinal disease. We aimed to investigate the spatial relation between retinal function and morphology on optical coherence tomography (OCT) imaging supported by deep-learning (DL)-algorithms, whilst assessing the inter- and intradevice repeatability of MP in neovascular age-related macular degeneration (nAMD).

Methods : 40 eyes of 40 patients, 20 with nAMD and 20 healthy controls completed two consecutive MP examinations on MP3 and MAIA after eligibility was confirmed with OCT (Spectralis, 97 B-scans). A DL-algorithm, The Fluid Monitor (RetInSight) quantified intraretinal, subretinal fluid (IRF, SRF) and pigment epithelial detachment (PED) after all OCT B-scans were superimposed with 45 stimuli from the MP grid. The impact of fluid on sensitivity was analyzed via multivariate mixed effect models. Repeatability was assessed with intraclass correlation coefficient (ICC), Bland-Altman plots and coefficient of repeatability (CoR) over stimuli with fluid.

Results : 7.200 MP stimuli were analyzed. Mean sensitivity in nAMD and controls was 23±6 and 29±2dB in MP3 and 20±6 and 25±3dB in MAIA, respectively. Overall sensitivity showed significant differences in nAMD compared to controls (p<0.001). IRF and PED had a significant negative effect on sensitivity with estimates of -3dB/nl (p<0.001) in MP3 and -1dB/nl in MAIA (p<0.004) and -2dB/nl (p<0.001) on both devices, respectively. SRF had no significant impact on function in MP3 (p=0.09), but reached significance in MAIA (-1dB/nl,p=0.002). Repeatability in MAIA was worse in stimuli over IRF (CoR ±8dB) compared to SRF, PED (both ±7dB) and comparable between all fluid compartments in MP3 with CoR ±7dB for both IRF, SRF and ±6dB for PED. ICC was excellent for intra, -and interdevice measurements with 0.93 and 0.94 for consecutive runs and 0.87 and 0.92 between devices.

Conclusions : DL allows for exact quantification of fluid volume together with point-wise topographic correlation to retinal function. Point-wise correlation showed significantly impaired sensitivity in nAMD compared to controls, with IRF and PED as important predictors of reduced function. Assessment of repeatability in MP enhances the trustworthiness of MP as a functional endpoint in clinical trials and provides clinical evidence for resolution of retinal fluid by compartment and volume.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.