Incidence and risk factors of second eye involvement in myopic macular neovascularization

Purpose: To report the cumulative incidence and risk factors of second eye involvement after diagnosis of myopic macular neovascularization (MNV) in the first eye. Design: Retrospective analysis of longitudinal data from a tertiary hospital in the Netherlands. Participants: Patients with high myopia (spherical equivalent [SE] ≤ − 6 diopters [D]), of European ethnicity, who were diagnosed with active MNV lesion in 1 eye between 2005 and 2018. Fellow eyes were free of MNV or macular atrophy at baseline, and data were collected on the SE, axial length, and presence of diffuse or patchy chorioretinal atrophy and lacquer cracks. Methods: Incidence rate and 2-, 5-, and 10-year cumulative incidences were calculated; hazard ratios (HRs) of second eye involvement were analyzed for potential risk factors using Cox proportional hazard models. Main outcomes measures: Incidence of second eye involvement after onset of myopic MNV in the first eye. Results: We included 88 patients over a period of 13 years with a mean age of 58 ± 15 years, mean axial length of 30 ± 1.7 mm and SE −14 ± 4 D at baseline. Twenty-four fellow eyes (27%) developed a myopic MNV during follow-up. This resulted in an incidence rate of 4.6 (95% confidence interval [CI], 2.9–6.7) per 100 person-years and a cumulative incidence of 8%, 21%, and 38% at 2, 5, and 10 years, respectively. Mean time until MNV development in the fellow eye was 48 ± 37 months. Patients aged < 40 years at the initial presentation had a 3.8 times higher risk of bilateral myopic MNV (HR, 3.8; 95% CI, 1.65–8.69; P = 0.002). The presence of lacquer cracks in the second eye seemed to increase risk, but this did not reach statistical significance (HR, 2.25; 95% CI, 0.94–5.39; P = 0.07). Conclusions: Our study of high myopes of European descent shows very similar incidence rates for second eye myopic MNV compared with Asian studies. Our findings substantiate the importance for clinicians to monitor closely and create awareness, especially in younger patients. Financial Disclosure(s): The authors have no proprietary or commercial interest in any materials discussed in this article.