Keywords: Sickle Cell Retinopathy, Optical Coherence Tomography (OCT), safety-net hospital, sickle cell disease

Background: Sickle Cell Disease (SCD) is an inherited hemoglobinopathy characterized by abnormal hemoglobin S. This leads to the “sickling” of red blood cells under low oxygen conditions. These sickled cells are prone to causing vaso-occlusion, resulting in a range of complications, including pain crises, stroke, and organ damage.

Sickle Cell Retinopathy (SCR) is a common ocular complication of SCD, particularly in patients with the HbSC and HbS/β+-thalassemia genotypes. SCR can progress to Proliferative Sickle Cell Retinopathy (PSCR), characterized by neovascularization, which can lead to vitreous hemorrhage, retinal detachment, and ultimately vision loss if left untreated. Early detection and management of SCR are crucial to prevent severe visual impairment in affected individuals.

Objective: This study aims to identify risk factors associated with the early occurrence and progression of Sickle Cell Retinopathy (SCR) observed in Optical Coherence Tomography (OCT) in patients diagnosed with Sickle Cell Disease (SCD). 

Methods: A retrospective cohort analysis will be conducted to determine the prevalence of SCR in patients with sickle cell disease. Using OCT imaging collected at routine screening in patients with SCD, we will identify the diagnosis of SCR and the time from SCD diagnosis to SCR diagnosis. The study will utilize existing medical records from 32 patients who were followed in the pediatric and adult hematology clinic at Harbor-UCLA Medical Center. Data will be collected on demographic characteristics, clinical features, laboratory findings, and ophthalmologic examinations. Using the Cox proportional hazards model, risk factors that are significantly associated with the early development of SCR will be identified. The analysis will include univariate Cox models to assess the crude association between each risk factor and the time to onset of SCR, followed by multivariate Cox models to adjust for potential confounders and identify independent predictors of early SCR occurrence.
                                                           
Results & Conclusions: Data analysis is currently ongoing. We anticipate that the patients with a history of smoking, a history of previous sickle cell crises, and advanced age will exhibit decreased time to onset of SCR diagnosis and increased rate of SCR progression. With this data, identifying risk factors can inform future guidelines for SCD management and screening to prevent vision loss in patients living with SCD. For future studies, it would be useful to compare the prevalence of SCR and vision loss to other healthcare facilities and uncover specific barriers that are causing disparities among healthcare settings.