Fluctuations in Retinal Thickness in Patients with Neovascular Age-Related Macular Degeneration Treated with Anti-Vascular Endothelial Growth Factor Agents

Abstract

Purpose : Improvement in retinal thickness after anti-vascular endothelial growth factor (VEGF) treatment for patients with neovascular age-related macular degeneration (nAMD) is poorly correlated with functional visual outcome. As current measures of retinal thickness fail to account for fluctuations in retinal thicknesses over time, here we hypothesize that larger variability in retinal thicknesses in nAMD eyes have poorer visual acuity (VA) up to 12 months after initial intravitreal injections of anti-VEGF agents.

Methods : We performed a retrospective, non-comparative, non-randomized cohort study of 203 patients with treatment-naïve nAMD at the Cleveland Clinic Cole Eye Institute. Central subfield thickness (CST) was measured from spectral domain optical coherence tomography (OCT) scans in patients over a 12 month period at 3 month intervals from January 1^st, 2012 to October, 31^st, 2019. For each patient, the standard deviation (SD) of the CST was calculated to represent variability in retinal thickness. Patients were excluded if they had maculopathies unrelated to nAMD that would interfere with analysis. Baseline demographics and VA were also recorded at each visit and then statistically compared to the SD of CST utilizing a linear mixed-effects regression model.

Results : Mean CST SD for the cohort was 45 ± 41 μm (mean ± SD). Baseline CST was 331 ± 92 μm and the mean final CST was 270 ± 59 μm (p < 0.001). Mean number of injections was 8.3 ± 2.6. The mean baseline VA was 61 ± 18 ETDRS letters with a final VA at 12 months of 65 ± 18 ETDRS letters (p = 0.013). Linear mixed effects regression modeling demonstrated that CST SD had a significant negative association with VA at 12 months (p = 0.001) when adjusting for baseline variables and injections.

Conclusions : Our study suggests that increases in variation in retinal thickness in patients with nAMD undergoing treatment with anti-VEGF agents is associated with poorer VA outcome. Further analysis will elucidate whether other OCT parameters and morphological features can provide further insight into functional visual outcome.

This is a 2020 ARVO Annual Meeting abstract.

 

An effects plot of CST SD and 12 month VA utilizing the mixed effects model. The shaded area represents the pointwise confidence band for the fitted values and the rug plot at the bottom of the graph shows the location of the CST SD values.