Response to treatment of epiretinal neovascularization secondary to ischemic retinal vein occlusion in proliferative MacTel 2

To describe a case of unilateral epiretinal neovascularization (ERN) secondary to an old ischemic retinal vein occlusion (RVO) in a patient with bilateral proliferative macular teleangiectasia type 2 (MacTel 2; Toto stage 4) and its response to treatment as documented by multimodal imaging. Retrospective case report A 75-year-old woman with a six-year-history of MacTel 2 and the consecutive development of proliferative outer retinal neovascularization in both eyes over time presented with an ERN in addition to neovascularization of the optic disc, delayed filling of the retinal veins, peripheral capillary ischemia and intravitreal hemorrhage only in her left eye in September 2023. She was therefore treated with anti-vascular endothelial growth factor (anti-VEGF; aflibercept 2mg) intravitreally. The ERN responded well to a single intravitreal injection of anti-VEGF, while flow in the outer retinal proliferation persisted. Diagnosis and treatment with anti-VEGF were observed via optical coherence tomography angiography. We believe that the ERN formation was a reaction to ischemia of the inner retinal capillary plexus due to a preceding RVO. The herein presented case provides a new perspective on the development and treatment of ERN in MacTel 2.