Modern diagnostic possibilities for peripapillary neovascular membranes. Report 2. Differential diagnostic features

Hemangiomas of the optic nerve head (ONH) is a rare hamartoma that in some cases requires differential diagnosis with peripapillary subretinal neovascular membranes (SNMs). OBJECTIVE: The study aimed to identify the clinical and tomographic differential diagnostic signs of ONH hemangiomas and juxtapapillary SNMs. MATERIAL AND METHODS: The study included 61 patients aged 22-90 years: 14 eyes with ONH hemangiomas and 58 eyes with SNMs of various etiologies (neovascular age-related macular degeneration, angioid streaks, pachychoroid neovasculopathy, and chronic central serous chorioretinopathy). In addition to standard ophthalmic examination, all patients underwent optical coherence tomography (OCT) and OCT angiography (OCT-A) using the OCT-2 Spectralis system (Heidelberg Engineering, Germany). RESULTS: ONH hemangiomas were detected in younger patients (46±17 years), whereas SNMs were found in older patients (65-76 years). Hemangiomas were located juxtapapillary, with no preferred side relative to the ONH, whereas SNMs were located predominantly temporal to the ONH and were often bilateral. Retinal thickness at the lesion site was significantly greater in hemangiomas (962±336 µm vs 424-563 µm in SNMs). Subfoveal choroidal thickness in hemangiomas corresponded to the age norm, whereas in SNMs it varied depending on the etiology. OCT showed that ONH hemangiomas were characterized by a "honeycomb-like" intraretinal structure, absence of edema over the lesion, and an intact Bruch's membrane; SNMs were characterized by intraretinal edema, pigment epithelial detachment, and accumulation of intraretinal and subretinal fluid. OCT-A showed that vessels in ONH hemangiomas were located in the superficial or deep retinal capillary plexus, whereas in SNMs they were located at the level of the avascular retinal layers. CONCLUSION: ONH hemangiomas are unilateral lesions detected in young patients and primarily affecting the inner retinal layers with formation of a "honeycomb-like" structure. SNMs are more often a bilateral process involving the outer retinal layers and associated with age-related or pathologic choroidal changes. An important differential diagnostic feature is the level of localization of the pathologic vessels on OCT-A. Therefore, comprehensive diagnostics, including ophthalmoscopy, OCT, and OCT-A, are important for diagnosis and for choosing the correct treatment strategy.