Clinical characteristics and treatment outcomes of bilateral myopic macular neovascularization in high myopic patients

To evaluate the clinical features and treatment outcomes of bilateral myopic macular neovascularization (mMNV). This single-centre retrospective study included patients with bilateral high myopia who were newly diagnosed with unilateral mMNV (first eye) between January 2008 and July 2020. Patients who presented with mMNV or macular atrophy suggestive of previous mMNV in the fellow eye (second eye) were excluded. Patients were classified into unilateral or bilateral groups based on mMNV development in the second eye during follow-up of >36 months. Ninety-three patients were included with the mean age of 55.4 ± 13.1 years and 71 (76.3%) were female. The mean baseline spherical equivalent was -13.0 ± 5.5 diopters. Of total, 21 (22.6%) developed mMNV in the second eye during the mean follow-up period of 95.1 ± 38.9 months; the cumulative probabilities were 16.2% at 5 years and 28.9% at 10 years after the first eye mMNV development. The uninvolved second eyes of the unilateral group had shorter axial length (AL) and greater subfoveal choroidal thickness than the eyes with mMNV. The unilateral group showed a greater interocular difference in AL than the bilateral group (p < 0.001). The presence of lacquer cracks in the second eye was identified as a significant risk factor for the second eye mMNV development (HR = 5.64, 95% CI: 1.59-20.08, p = 0.008). In the bilateral group, the second eye showed less vision improvement after anti-VEGF treatment, but the final visual acuity and cumulative probability of fovea-involving mMNV-related chorioretinal atrophy did not differ between the eyes. Approximately 30% of bilateral high myopic patients with unilateral mMNV are estimated to develop mMNV in the second eye over a period of 10 years. The presence of lacquer cracks in the second eye was a significant risk factor. The first and second eyes showed comparable treatment outcomes.