Abstract
Purpose :
Fabry disease (FD) is an X-linked recessive hereditary lysosomal storage disorder which results in the accumulation of glycosphingolipids in various organs including the eye. Ocular manifestation of FD include cornea verticillata and conjunctival and retinal vascular abnormalities. The purpose of this study was to analyze the retinal vasculature using swept-source optical coherence tomography angiography (SS OCTA) in patients with FD.
Methods :
Images (a 3x3 and 6x6 mm cube centered on the fovea) were acquired in 16 eyes of 8 healthy individuals and 28 eyes of 14 patients with FD using a SS OCTA device (central wavelength 1060 nm; A-scan rate of 100,000 scans per second). The data analysed were taken from one eye only of each subject. En face images of the retinal vasculature were generated from the superficial and deep capillary plexus (SCP/DCP). Quantitative analysis of the vessel density (VD) and vessel length density (VLD) was performed manually. Vessel density was assessed as the ratio of the retinal area occupied by vessels. Vessel length density was measured as the total length of the skeletonized vessels using 1-pixel centreline extraction of the blood vessels.
Results :
Among the patients with FD the mean age was 47 (±14 SD) years with 43% male and in the healthy individuals 29 years (±5 SD) with 25% male. The mean VD of the SCP in FD-group was 0.47 (3x3mm) / 0.46 (6x6mm), the VLD of SCP was 25.30 (3x3mm) / 19.89mm-1 (6x6mm), the VD of DCP was 0.46 (3x3mm) / 0.47 (6x6mm) and the VLD of DCP was 25.56 (3x3mm) / 21.07mm-1 (6x6mm). In the control group the mean VD of SRL was 0.49 (3x3mm) / 0.48 (6x6mm), the VLD of SCP was 25.87 (3x3mm) / 20.85mm-1 (6x6mm), the VD of DCP was 0.50 (3x3mm) / 0.49 (6x6mm) and the VLD of DCP was 27.01 (3x3mm) / 21.94mm-1 (6x6mm). There was a statistically significant reduction in both VD and VLD of DCP in FD group (p<0.05) compared to controls. Further there was a statistically significant reduction of VLD of SCP in 6x6mm cubes.
Conclusions :
Swept-source OCTA of the microcirculation in eyes of patients with FD can be used to quantitatively demonstrate alterations in the superficial and deep capillary plexus compared to healthy eyes. The reduction of the capillary network in the deep capillary plexus could be clinically significant and future longitudinal studies may use these metrics to evaluate changes over time and its correlation to disease severity.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.