Choroidal Vascularity Index, Retinal Vascularity and Hemoglobin Levels in Pediatric Sickle Cell Maculopathy

Purpose: To evaluate the choroidal vascularity index (CVI) in pediatric patients with sickle cell disease (SCD) and its associations with retinal thickness and vasculature. Methods: This is a retrospective case series of children with sickle cell disease (SCD) and healthy age matched controls. CVI was measured using an automated machine learning algorithm. Retinal assessments included total retinal thickness along with vessel density (VD). Results: A total of 184 eyes from 92 pediatric SCD patients (55.4% male) were included. Eyes with low CVI had significantly lower median VD in the inferotemporal quadrant compared to eyes with higher CVI (14.8 vs 22.2; p = 0.009). Eyes with lower CVI had higher median retinal thickness in the nasal perifovea (322 μm vs 316 μm; p = 0.003) and the inferior perifovea (293 μm vs. 290 μm; p = 0.0028). Eyes with low CVI had significantly lower mean Hgb level (9.3 vs 10; p = 0.009). The mean CVI in the control group was 69%,which was significantly higher than the CVI in the studied population with a mean CVI of 54%, p < 0.001 Conclusion: In pediatric SCD patients, there was a significant decrease in CVI when compared to healthy age matched controls. Decreased CVI was associated with a loss of retinal VD in the inferotemporal macular quadrant as well as lower Hgb levels. These findings suggest a role of choroidal ischemia in the pathogenesis of sickle cell maculopathy and a potential for CVI to serve as a biomarker for systemic disease activity.