Optical Coherence Tomography Angiography in Stargardt Disease

Abstract

Purpose : To describe qualitative and quantitative vascular abnormalities in patients affected by Stargardt Disease (STGD) evaluated using optical coherence tomography angiography (OCTA)

Methods : Retrospective cross-sectional study. We included patients affected by STGD confirmed by the detection of pathogenic mutations in ABCA4 gene. After a complete ophthalmological examination and retinography, structural B-scan OCT and OCT angiography (RS-3000 Advance SD-OCT, Nidek; Gamagori, Japan) were performed. We assessed the vascular density of superficial capillary plexus (SCP, mm²), the vascular density of deep capillary plexus (DCP, mm²), foveal avascular zone area (FAZ, mm²), central retinal thickness (CRT, µm). Qualitative evaluations of the SCP, DCP and choriocapillaris (CC) layer were also performed

Results : Thirty-seven patients (74 eyes) with a diagnosis of STGD were evaluated (20 females, 17 males). The mean age was 39.5 ± 15.4 years (range 13-81). The mean BVCA (logMAR) was 0.59±0.38. Nineteen healthy subjects (38 eyes) were considered as a control group for comparison. Qualitative analysis of OCTA showed a rarefied vascular network pattern and capillary morphological abnormalities in most STGD eyes both in SCP (66%) and DCP (92%). We observed a rarefaction of perifoveal capillary network texture in 86% of affected patients. Irregular FAZ borders and increased FAZ area were observed in all STGD patients, while a pseudo-enlargement of FAZ was observed in 56% of eyes. Different degrees of choriocapillaris impairment were observed in all STGD eyes. The quantitative analysis did not show a statistically significant difference in the vascular density of the SCP between STGD patients and controls. A severe and statistically significant reduction of DCP vascular density and an increased FAZ area were found in STGD patients in comparison with controls (p<0.0001 in both cases). CRT was reduced in STGD patients in comparison with controls (p<0.0001). DCP vascular density was directly correlated with visual acuity (r=-0.37) and CRT (r=0.39)

Conclusions : Our study showed by means of OCTA significant vascular abnormalities in STGD patients in comparison with the controls: the most significant vascular abnormalities can be identified in the DCP and in the choriocapillaris. In STGD OCTA may provide useful information for diagnosis, prognostic assessment, and patients selection for clinical trials.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.