Optical coherence tomography angiography of choroidal neovascularization in four inherited retinal dystrophies

Abstract

Purpose: To demonstrate the clinical utility of optical coherence tomography (OCT) angiography (OCT-A) in inherited retinal dystrophies complicated by choroidal neovascularization (CNV). Methods: Optical coherence tomography angiography and structural OCT were performed using a 70-kHz spectral domain OCT system using the split-spectrum amplitude-decorrelation angiography algorithm. Semiautomated image processing software was used to segment and measure the CNV. Results: Four participants were enrolled to study the following inherited retinal dystrophies complicated by CNV: choroideremia, EFEMP1-related retinopathy, Best vitelliform dystrophy, and adult-onset vitelliform dystrophy. Interpretation of fluorescein angiography was difficult because of abnormal retinal architecture but suggested the presence of CNV. Structural OCT revealed subretinal or subretinal pigment epithelium fibrovascular tissue, within which flow signal was observed on OCT-A. The CNV morphology varied from dense capillary networks in active lesions to asymptomatic large caliber loops. Baseline CNV vessel areas ranged from 0.07 mm 2 to 0.98 mm 2. After treatment with intravitreal bevacizumab, the CNV in choroideremia decreased in the vessel area then rebounded, whereas the one in EFEMP1-related retinopathy remained largely unchanged. Conclusion: Optical coherence tomography angiography enables morphologic characterization and quantification of CNV in patients with retinal dystrophies despite distorted retinal architecture, can assess response to treatment, and may facilitate differentiation between active and regressed lesions.