Type 4 macular neovascularization in eyes with diabetic retinopathy

PURPOSE: To report recently described type 4 macular neovascularization (T4MNV) in eyes with diabetic retinopathy (DR). METHODS: A retrospective analysis including nine eyes with DR (and without any features of age related macular degeneration or AMD) that displayed T4MNV with optical coherence tomography (OCT) and OCT angiography (OCTA). RESULTS: The mean age of the patients was 64 years, and the mean duration of diabetes mellitus was 20 years. All patients displayed unilateral T4MNV with an average visual acuity of 20/500 in the affected eye. Seven of the nine patients (77.8%) were diagnosed with proliferative DR, and the remaining exhibited severe non-proliferative DR. Central posterior hyaloid fibrosis was detected in 7/9 eyes (77.8%) and showed flow on OCTA in 4/9 eyes (44.4%). All 9 eyes showed subretinal hyperreflective material (SHRM) on OCT corresponding to Type 2 (and Type 1) MNV on OCT and OCTA. Drusen were not detected in any of the 9 affected or fellow eyes. CONCLUSION: T4MNV can occur in eyes with long-standing DR without signs of AMD. It is possible that early identification of T2MNV and timely anti-VEGF intervention may potentially mitigate progression to T4MNV, but this requires validation with prospective analysis. Early recognition of T4MNV imaging features is important in counseling patients about the poor visual prognosis.