Impact of Residual Subretinal Fluid Volumes on Treatment Outcomes in a SRF-tolerant Treat & Extend Regimen

Abstract

Purpose : To investigate associations between residual subretinal fluid (SRF) volumes, quantified using artificial intelligence (AI) and treatment outcomes in a SRF-tolerant treat and extend (T&E) anti-VEGF regimen in neovascular age-related macular degeneration (nAMD).

Methods : In this post-hoc analysis, patients enrolled in the prospective, multicenter FLUID study and randomized in a SRF-tolerant T&E regimen were examined by spectral-domain optical coherence tomography (SD-OCT) imaging and tested for best-corrected visual acuity (BCVA) over a 24 months follow-up. Validated AI-based image analysis tools were used to quantify SRF and intraretinal fluid (IRF) volumes on SD-OCT. 375 visits of 98 patients of the SRF tolerant arm were divided into two subgroups: Extended intervals despite residual SRF, and visits with extension without fluid. BCVA change at the follow-up visit was compared between the groups. The associations of SRF volumes in the central 1mm and 6mm as well as treatment intervals with BCVA change were estimated using generalized linear mixed models.

Results : At visits with extended intervals despite residual SRF an increase in SRF was associated with a significant BCVA reduction at the next visit in the central 1mm (-0.138 letters/nl SRF; p=0.014) and the total 6mm (-0.024 letters/nl SRF; p=0.049). Visits with extended intervals despite residual SRF had significantly higher SRF volumes in the central 6mm (p=0.002) at the following visit, and showed a trend in the central 1mm (p=0.061). A statistically significantly negative association between increased treatment interval and change in BCVA was found for residual SRF in 1 and 6mm (-0.250 and -0.233 letter/week interval, respectively, both p<0.001).

Conclusions : A fully automated quantitative analysis of extended visits despite residual SRF demonstrated increasing SRF volumes associated with BCVA loss at the following visit. This association contributes to our understanding of the quantitative impact of residual SRF volumes on visual function and highlights the importance of precise and quantitative measurements of fluid volumes as the field determines the most efficacious regimens for individualizing treatment for nAMD with anti-VEGF therapies.

This is a 2021 ARVO Annual Meeting abstract.