Severe vision loss secondary to retinal arteriolar occlusion after multiple intravitreal brolucizumab administrations

Purpose: To describe a case of unilateral retinal arteriolar occlusion following multiple intravitreal brolucizumab injections for neovascular age-related macular degeneration (nAMD). Observations: A 92-year-old Caucasian woman presented with blurry vision in her left eye (OS) after receiving the third dose of intravitreal brolucizumab. At the time of presentation, visual acuity (VA) was 20/40 in her right eye (OD) and had decreased from 20/150 to count finger (CF) at 1-foot OS. On examination, there was no evidence of active inflammation in the anterior chamber OU. Dilated fundus examination showed no vitritis in OD and 1+ vitreous cells OS, flame-shaped hemorrhage at the superior optic disc margin, and retinal whitening surrounding the proximal portion of the supero-temporal branch of the central retinal artery. There were drusen in OS and retinal pigment epithelial (RPE) changes in the maculae of OU. Intra-arteriolar greyish deposits were seen OS. Fluorescein angiography (FA) showed hyper-fluorescence in the maculae corresponding to fibrovascular pigment epithelial detachments (PED) OU. No peri-vascular leakage was noted OU. Delayed filling of multiple arterioles in early and late phases OS was observed on FA. The patient was diagnosed with retinal arteriolar occlusion associated with repeated intravitreal brolucizumab administrations. Conclusion: Retinal arteriolar occlusion with severe vision loss, possibly secondary to inflammatory responses, can occur after subsequent intravitreal brolucizumab injections, even if no inflammation occurred after initial administrations. Vaso-occlusive disease should be considered as a potential ocular complication, with acute as well as delayed onset, following intravitreal brolucizumab therapy.