Abstract
Purpose :
To analyze the vascular density (VD) and fractal dimension (FD) of the superficial capillary plexus (SCP) and the deep capillary plexus (DCP) in patients with SCD imaged with OCTA and to compare the findings according to their genotype.
Methods :
Consecutive patients referred for ophthalmological examination in the context of SCD were prospectively included between November 2017 and October 2018. Patients underwent a complete ophthalmological examination, including 3x3 mm OCTA performed using Heidelberg Spectralis OCT2 beta angiography module ( Heidelberg Engineering GmbH,Germany). VD of the SCP and DCP were computed using ImageJ software (NIH, Bethesda, Maryland, USA). Skeletonized images were used for computing FD using Fractalyse(ThéMA) software.
Results :
One hundred and ten eyes of 57 patients, of which 50 eyes (51.81%) with HbSS SCD, 45 eyes (40.90%) with HbSC SCD and 15 eyes (13.63%) with HbS-Beta thalassemia were included. At the level of the SCP, in the HbSS group both VD and FD were significantly lower compared to the HbSC group (VD: 30.89% vs 34.36%, p =0.009; FD: 1.57 vs 1.61, p<0.001). Moreover, VD differed significantly in the SCP between HbSC and HbS-Beta thalassemia group (VD 34.36% vs 30.04%, p = 0.015). In the DCP, in the HbSS group both VD and FD were significantly lower compared to the HbSC group (VD: 23.34% vs 25.55%, p =0.04; FD: 1.56 vs 1.60, p<0.001). A significant difference was found between HbSS and HbS-Beta thalassemia in terms of FD in the DCP (p=0.02).
Conclusions :
The HbSS genotype of sickle cell patients presents a significantly lower VD and FD in both capillary plexa, suggesting, by means of OCTA, a more severe macular involvement than in HbSC and the HbS-beta thalassemia genotype.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.