Evaluation of retinal tissue and vascular changes in sickle cell disease

ABSTRACT Evaluation of Retinal Tissue and Vascular Changes in Sickle Cell Disease Purpose: In patients with sickle cell disease, retinal tissue and vascular structure were evaluated by optical coherence tomography angiography in the early period, before the clinical findings of retinopathy were revealed. The diagnostic value of the data obtained and its place in prognosis were investigated. Methods: 50 eyes of 25 patients with sickle cell disease were included in the study. 50 eyes of twenty-five healthy individuals were determined as the control group. The best corrected visual acuity (BCVA) of the patient group was determined and full ophthalmologic examinations were performed. Optical coherence tomography angiography examination (OCTA) was performed. The same was done for the control group. In the vascular retinal segment where the superficial and deep capillary plexus are evaluated together, foveal avascular zone (FAZ) in mm2 and capillary density (FAZ Fractal Dimension) in 1 mm radius area around FAZ in % was automated analyzed in the OCTA. In superficial and deep capillary plexus, vascular density was measured in six areas including central retina, fovea, parafovea, upper, lower, nasal, temporal quadrant. All the imaging parameters obtained were also analyzed for the control group. Results: 16 (64%) of the patients were female and 9 (36%) were male, and the mean age was 17.6 ± 9.921 (4-44). 24 of the patients had Hb-SS and one had HbSβThal genotype. In all patients, BCVA was full in Snellen chart and 0 in logMAR. Anterior segment biomicroscopic examinations were normal, intraocular pressure values were within normal limits. There was a statistically significant difference between the two groups in the temporal quadrant retinal thickness (p = 0.023) and was thinner in the sickle cell disease group. In the sickle cell disease group, there was a positive correlation between temporal quadrant retinal thickness and foveal retinal thickness, central retinal thickness, and deep capillary plexus foveal capillary density (p <0.05). Negative correlation was detected with flow area in choriocapillary plexus (p <0,05). A positive correlation was observed between the temporal quadrant retinal thickness with foveal retinal thickness, central retinal thickness, and foveal capillary density in the superficial capillary plexus in the control group. (p <0,05). There was a negative correlation between FAZ area, FAZ FD value, non flow area in the superficial capillary plexus and flow area in the choriocapillary plexus. (p <0,05). No statistically significant difference was observed between the two groups in terms of vessel densities in the superficial and deep capillary plexus. There was no statistically significant difference between the two groups in terms of FAZ area. Conclusions: Sickle cell disease is a hemoglobinopathy that causes vascular changes in the peripheral and central retina. OCTA is a new imaging method that may have value in the stage before the clinical examination findings appear in the retina, especially in the imaging of central retinal changes and early diagnosis. Non invasive, detailed imaging of the retinal vasculature in layers are important advantages. However, new studies are needed to determine the diagnostic value of sickle cell disease retinopathy. Keywords: Optical coherence tomography angiography, sickle cell disease retinopathy, temporal quadrant retinal thickness