Objective: To compare clinical characteristics of patients suffering from neovascular age-related macular degeneration (nAMD) with mature and immature choroidal neovascularisation (CNV) as assessed by optical coherence tomography angiography (OCTA). To explore the effect of total anti-vascular endothelial growth factor exposure on the occurrence of mature CNV when correcting for potential confounders.
Methods and analysis: In this retrospective case series, we included 40 eyes of 36 patients with nAMD with CNV assessed by OCTA at the Manchester Eye Hospital between June 2016 and June 2017. A retinal specialist masked to patient information graded CNV depicted on OCTA scans. For statistical comparisons, we used t-tests, Fisher's exact tests and a mixed-effects logistic regression model.
Results: 18 patients (20 eyes) were treatment naïve, and the mean number of intravitreal injections (IVI) in the remaining eyes was 18.4 (range 2-71). The mean duration of nAMD was 19.3 months (range 0-87.4). 25 eyes (62.5%) exhibited mature CNV. Eyes with mature CNV did not differ from those with immature CNV regarding age (+2.8 years; p=0.288) or duration of disease (+9.4 months; p=0.061). However, they had a higher number of IVIs (+3.1; p=0.035). Among eyes with best corrected visual acuity over 25 letters, there was a strong association between the number of IVIs (0 vs 1-20: OR 68.01 [95% CI 1.30 to 3546.99; p=0.036], 0 vs >20 IVI: OR 380.01 [95% CI 2.60 to 55 464.89; p=0.019]) and maturity status when correcting for potential confounders.
Conclusion: Maturity status of CNV as assessed by OCTA may indicate treatment exposure of CNV in nAMD.
Keywords: neovascularisation; retina; treatment medical.