Modern diagnostic possibilities for peripapillary neovascular membranes. Report 1. OCT diagnostic signs

Peripapillary subretinal neovascular membranes (SRNVMs) develop due to neovascular age-related macular degeneration (nAMD), retinal angioid streaks, inflammatory diseases, congenital optic disc anomalies, and other causes. Diagnosis of peripapillary SRNVMs relies on multimodal imaging, with optical coherence tomography (OCT) being the main method. Objective. The study aimed to identify differential diagnostic signs of peripapillary SRNVMs of various etiologies according to OCT data. Materials and methods. We examined 48 patients with active peripapillary SRNVMs. All patients underwent OCT, including OCT angiography. Quantitative and qualitative characteristics were evaluated. Results. In nAMD, peripapillary SRNVMs presented as fibrovascular retinal pigment epithelium (RPE) detachment (p=0.05), with a “double-layer” sign and drusen in one-third of cases (p=0.017). Subfoveal choroidal thickness in patients with nAMD did not differ significantly from the age-related norm (p=0.473 and p=0.384 for the study and fellow eyes, respectively); the inner choroidal surface had a smooth profile (p=0.033), and the Bruch membrane was preserved (p=0.033). In angioid streaks, OCT visualized a thin choroid with folding of the inner surface (p<0.0001) and ruptures of the Bruch membrane (p<0.0001). In the area of peripapillary SRNVM, choroidal thickness was lower than in patients with nAMD (p=0.024) and pachychoroid spectrum diseases (p<0.0001). In pachychoroid-related SRNVMs, choroidal thickness in the SRNVM area and subfoveally, both in the study and fellow eyes, significantly exceeded the values observed in SRNVMs of other etiologies (p<0.0001). RPE changes mainly presented as a shallow local detachment (p=0.02) with a saw-tooth contour and no defects. Subretinal hyperreflective material in the SRNVM area was also absent (p=0.02), but isolated subretinal fluid predominated in pachychoroid neovasculopathy (p=0.004), whereas a combination of subretinal and intraretinal fluid was more prevalent in chronic central serous chorioretinopathy. Conclusion. To correctly determine the type of peripapillary SRNVM, it is necessary to pay primary attention to the condition of the choroid and Bruch membrane, the presence of drusen and subretinal hyperreflective material in the SRNVM area and subfoveally, presence of fluid in the SRNVM area, and the condition of the fellow eye.