Choroidal Thickness and Visual Outcomes After 2 Years of Treat-and-Extend Protocol in Neovascular Age-Related Macular Degeneration

Abstract

INTRODUCTION: To investigate whether baseline subfoveal choroidal thickness (SFCT) is correlated with functional response to anti-vascular endothelial growth factor (VEGF) treatment in neovascular age-related macular degeneration (nAMD).
METHODS: We conducted a retrospective observational study using data from the national Retina Study Group database. The study included 82 eyes from 67 treatment-naïve patients diagnosed with typical nAMD. Included eyes received a loading dose of 3 anti-VEGF intravitreal injections (ranibizumab, bevacizumab or aflibercept) and were managed thereafter following a treat-and-extend (TAE) regimen. Subfoveal choroidal thickness (SFCT) measurements were obtained at baseline, 6, 12, and 24 months. We classified the eyes into thin, medium, and thick choroid groups based on the mean and one standard deviation of baseline SFCT measurements. The functional response was assessed through best-corrected visual acuity (BCVA) evaluations using the ETDRS scale.
RESULTS: The study found a significant decrease in SFCT and improvement in BCVA at the 24-month mark compared to baseline (p-value <0.001). Among the studied eyes, the mean baseline SFCT was 234.5 ±79.2 μm, decreasing by 9.2% over the 24-month period (p-value <0.001). The thin choroid group exhibited a smaller SFCT decrease compared to the thick choroid group (p-value <0.001). BCVA improved from a baseline value of 50.6 ± 17.8 to 59.4 ± 17.5 ETDRS letters after 24 months, corresponding to an overall gain of 8.8 ± 18.3 ETDRS letters (p-value= 0.001). Eyes with thinner choroids at baseline showed a higher gain on BCVA, +15.2 letters at 24 months, compared to medium and thick choroid groups (+7.8 and +5.9 letters at 24 months, respectively), although this difference did not reach statistical significance (p-value > 0.05).
CONCLUSION: Long-term anti-VEGF treatment in nAMD patients following a TAE regimen is associated with significant SFCT decrease and BCVA improvements. Thicker baseline choroids may be linked with poorer functional outcomes at 24 months. Further investigations with larger sample sizes are needed to validate this data and better understand the role of different anti-VEGF agents and treatment regimens in nAMD patients’ functional outcomes.