Novel Manifestation of Retinal Hemangioblastomas Detected by OCT Angiography in von Hippel-Lindau Disease

To elucidate the clinical characteristics of atypical retinal vascular proliferation in patients with von Hippel-Lindau (VHL) disease using OCT angiography (OCTA).Prospective, observational study.Fifty-seven consecutive patients with a diagnosis of VHL disease who visited Kyoto University Hospital between January 2019 and March 2022.Retinal hemangioblastomas (RHs) were assessed using multimodal imaging including OCTA. Retinal hemangioblastomas were classified into 2 phenotypes: nodular and flat. Nodular RHs were defined as typical RHs that were globular, well-circumscribed tumors, often accompanied with dilated feeder arterioles and draining venules. Flat RHs lacked a protruded red or colored mass, had variable and indistinct borders, and were not accompanied with feeder and draining vessels.The prevalence, distribution, and description of atypical flat RHs.Among 57 consecutive patients with VHL disease, 37 patients (64.9%) showed RHs in at least 1 eye. Bilateral RHs were seen in 23 patients (62.2%). Among 58 eyes of 37 patients with RHs, typical nodular RHs were detected in 54 eyes. Nodular RHs were seen mainly in the peripheral retina and occasionally in the peripapillary region, and they showed exudative changes in some cases. Flat RHs were detected in 7 eyes (12.1%). Four eyes showed only flat RHs, and 3 eyes showed both types in the same eye. Most flat RHs appeared as retinal hemorrhages or faint flat abnormal retinal vessels in the inner retina on the fundus examination, often within the macula area or peripapillary. In all eyes with flat RHs, OCTA showed abundant blood flow in the lesions. OCT revealed that flat RHs were seen mainly between the retinal nerve fiber layer and the ganglion cell layer, and occasionally within the inner nuclear layer. During a mean follow-up period of 20.4 ± 15.0 months, no flat RHs accompanied exudative change, tractional retinal detachment, or progression in size.Patients with VHL disease can demonstrate 2 distinct types of RHs: the classic nodular type and an atypical flat type. OCT angiography can be useful in improving the detection of atypical flat RHs, which can be difficult to detect clinically.Proprietary or commercial disclosure may be found after the references.