Optical coherence tomography angiography of ill-defined choroidal neovascularization with fluorescein angiography

Abstract

Background Optical coherence tomography angiography (OCTA) is used to diagnose choroidal neovascularization (CNV). It can detect blood flow at different levels using an en face platform and directly provides morphological identification of pathological microvascular lesions. CNV results in the growth of blood vessels from the choroid mediated by Bruch's in the subretinal pigment epithelium or subretinal area. Aims This study was done to study the morphological structure of ill-defined CNV with fundus fluorescein angiography (FFA) by OCTA. Patients and methods This prospective cross-sectional, nonrandomized, noninterventional study that was done on 48 eyes of 35 patients who were diagnosed to have CNV by FFA, OCT, and OCTA imaging was performed using Topcon Corp. On OCTA imaging, the fovea was used. After full history and complete ophthalmologic examination, FA, OCT, and OCTA was done for all patients after papillary dilatation with Mydrapid eye drops. Results OCTA was superior to FFA in detection of clear vascular network, the exact location, and classification of CNV. It showed a statistically significant difference (P=0.001). Occult CNV and CNV suspicious in FFA appeared mainly as type I that had more volumetric angiographic information of CNV in choriocapillaris. Conclusion OCTA is better at detecting the exact type and location of ill-defined CNV (occult type-I CNV) compared with FFA and for defining the vascular network with high accuracy. It was able to aid in making the diagnosis in cases where evidence of CNV is uncertain following FFA.