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 (IRDs) complicated by choroidal neovascularization (CNV). Methods OCT-A and structural OCT were performed using a 70 kHz spectral-domain OCT system employing 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 IRDs complicated by CNV: choroideremia, EFEMP1-related retinopathy, Best vitelliform dystrophy, and adult-onset vitelliform dystrophy. Interpretation of fluorescein angiography was difficult due to abnormal retinal architecture but suggested the presence of CNV. Structural OCT revealed subretinal or sub-RPE fibrovascular tissue, within which flow signal was observed on OCT-A. CNV morphology varied from dense capillary networks in active lesions to asymptomatic large caliber loops. Baseline CNV vessel areas ranged from 0.07 to 0.98 mm2. Following treatment with intravitreal bevacizumab, the CNV in choroideremia decreased in vessel area then rebounded, while the one in EFEMP1-related retinopathy remained largely unchanged. Conclusions OCT-A enables the morphologic characterization and quantification of CNV in patients with retinal dystrophies despite distorted retinal architecture, can assess response to treatment, and may facilitate the differentiation between active and regressed lesions.

Optical Coherence Tomography Angiography Quantitative Assessment of Macular Neovascularization in Best Vitelliform Macular Dystrophy

“…[1][2][3][4][5][6][7][8][9][10][11] MNV has been previously described as a possible complication, especially in the early stages of VMD. 1,2,[10][11][12][13]25,26 In most cases, exudative manifestations due to MNV activity have been treated with anti-VEGF intravitreal injections, with positive outcomes. 11,25,26 The present study, based on OCTA assessment, revealed that MNV is actually a quite frequent manifestation of VMD, occurring in about two-thirds of cases overall.…”

Optical Coherence Tomography Angiography Imaging in Inherited Retinal Diseases

“…In later stages of CHM, choroidal neovascularization can develop, which can be difficult to detect on conventional angiogram. Patel et al demonstrated OCTA evidence of CNV with high flow signal in sub-RPE fibrovascular tissue [50]. Given the rarity of this disease and somewhat contradictory results in some of the above studies, additional OCTA studies enrolling larger number of patients are needed.…”

OCT-Based Velocimetry for Blood Flow Quantification

“…A different take on the amplitude decorrelation techniques consists of analyzing the properties of the members of the ensemble in Eqs. (8) and (9) instead of taking the ensemble average. This is in essence the principal component analysis (PCA) presented by Mohan et al [54] Experiments on phantoms showed the potential for flow velocity quantification of this method with a reduced number of data points.…”

“…Recently, OCTA became commercially available as a tool for qualitative, non-invasive, 3D visualization of the blood vessel network of the posterior eye. In research studies as well as in the daily clinical routine, OCTA is on the way to becoming an accepted imaging modality for the diagnosis of retinal vascular disorders including neovascularization [8,9] and retinal vein occlusion [10]. Current clinical implementations of OCTA provide an almost binary discrimination between static tissue and blood vessels with sufficient flow, and a very limited ability for flow velocity quantification.…”