Prevalence and risk factors for the development of physician-graded subretinal fibrosis in eyes treated for neovascular age-related macular degeneration

Purpose: To assess the prevalence and incidence of and risk factors for subretinal fibrosis (SRFi) in eyes with neovascular age-related macular degeneration (nAMD) that underwent vascular endothelial growth factor inhibitor treatment for up to 10 years.

Methods: A cross-sectional and longitudinal analysis was performed on data from a neovascular age-related macular degeneration registry. The presence and location of SRFi were graded by the treating practitioner. Visual acuity, lesion characteristics (type, morphology, and activity), and treatment administered at each visit was recorded.

Results: The prevalence of SRFi in 2,914 eyes rose from 20.4% at year interval 0-1 to 40.7% at year interval 9 to 10. The incidence in 1,950 eyes was 14.3% at baseline and 26.3% at 24 months. Independent characteristics associated with SRFi included poorer baseline vision (adjusted odds ratio 5.33 [95% confidence interval 4.66-7.61] for visual acuity ≤35 letters vs. visual acuity ≥70 letters, P < 0.01), baseline lesion size (adjusted odds ratio 1.08 [95% confidence interval 1.08-1.14] per 1000 µm, P = 0.03), lesion type (adjusted odds ratio 1.42 [95% confidence interval 1.17-1.72] for predominantly classic vs. occult lesions, P = 0.02), and proportion of active visits (adjusted odds ratio 1.58 [95% confidence interval 1.25-2.01] for the group with the highest level of activity vs. the lowest level of activity, P < 0.01). Conclusion: Subretinal fibrosis was found in 40% of eyes after 10 years of treatment. High rates of lesion activity, predominantly classic lesions, poor baseline vision, and larger lesion size seem to be independent risk factors for SRFi.