5596911 RETINAL AND MACULAR AFFECTION IN EGYPTIAN SICKLE CELL DISEASE PATIENTS USING SPECTRAL DOMAIN OCT AND OCT-ANGIOGRAPHY: A SINGLE CENTER STUDY

Abstract

Background: Sickle vasculopathy results from a complex interaction between sickles erythrocytes, white blood cells, platelets, activated endothelium, vasoactive factors and inflammation. Improved life expectancy of sickle cell disease (SCD) patients in recent years has led to emergence of more disease-related complications as ocular complications. Sickle maculopathy, an emerging subtle complication, characterized by local macular thinning secondary to ischemia is not always evident by indirect ophthalmoscope. In an earlier study of an Egyptian SCD cohort using flourscein angiography, we detected proliferative sickle retinopathy (PSR) in 32.5% of enrolled patients; youngest being 15 years old. Discrepancies in reported prevalences among pediatric SCD patients are attributed to different definitions of retinopathy, examining methods used, examiner’s ability, patients’ age and treatment modalities. Spectral domain- Optical Coherence Tomography (OCT) and Optical Coherence Tomography Angiography (OCT-A) are more recent non- invasive tools that allow for early detection of signs of PSR. Aim: This study aimed to assess for retinopathy and maculopathy among an Egyptian cohort of SCD patients using SD-OCT and OCT-A. Methods: This prospective observational cross-sectional study, conducted in Pediatric Hematology Unit, Cairo University Children Hospital, included 80 Egyptian steady state SCD patients (aged 10 years or more) and 20 unrelated healthy age and sex matched subjects as control group. Informed consents were given willingly by all subjects/ guardians before enrollment in the study. SD-OCT (Optovue OCT machine) and OCT-A (Optovue Octa machine) were performed for all enrolled subjects at Opthalmolgy Department, Cairo University. Results: All subjects had normal slit lamp examination. No statistically significant difference was found in best corrected visual acuity (BCVA) of RT eye, Lt eye, slit lamp bio-microscopy or indirect ophthalmoscopy between SCD and control groups (p= 0.059, 0.057, 0.159 & 0.159 respectively). Using SD-OCT, SCD patients had significantly lower mean Rt macular thickness than control group (218.05±19.13 vs 232.1±14.55 micrometer with p-value =0.003). Twelve SCD patients (15%) showed evidence of retinopathy by OCT-A. There was a significant relationship between OCT-A findings and both Rt and Lt macular thickness by SD-OCT (p-value <0.0001 and <0.0001 respectively). OCT-A findings well correlated with Rt BCVA, Lt BCVA, slit lamp bio-microscopy and indirect ophthalmoscope (p-value <0.0001 for all). SCD patients having abnormal OCT-A findings or with macular abnormalities by SD-OCT showed statistically significant higher mean transfusions/ lifetime and longer duration of Deferiprone chelation therapy (p=0.011, 0.014, 0.028 and 0.038 respectively). No significant difference was noted among SCD patients with abnormal vs normal OCT-A findings regarding their studied demographic, clinical or hematologic characteristics. Conclusion: Sickle retinopathy and maculopathy are subtle disease related complications that might affect SCD children and adolescents. SD-OCT and OCT-A are non-invasive useful tools for early timely detection of these complications thus minimizing the risk of sight- threatening retinopathy. Keywords: Retinopathy- Sickle- Egyptian- SD-OCT- OCT-A