Abstract
Purpose: :
Individuals with sickle cell disease (SCD) are at risk for developing proliferative retinopathy and vision–threatening complications. This study aims to determine the prevalence and age of onset of clinically significant retinopathy, and to suggest an appropriate timeframe for referral to ophthalmology.
Methods: :
We reviewed consecutive records from 1987 to 2005 retrospectively for children with SCD referred to the Ophthalmology Service at the Hospital for Sick Children, Toronto. Data obtained included age, sex, sickle cell genotype, and presence of systemic manifestations of SCD. The genotypes hemoglobin SS, SC, and SB–Thalassemia were considered separately for univariate and survival analyses.
Results: :
The hemoglobin SS group consisted of 163 patients. Over follow–up, 1 patient (0.06%) had PR (age at first eye findings 16 y), 23 patients (14.1%) had non–proliferative retinopathy (NPR), and 139 patients (85.3%) had no retinopathy. The hemoglobin SC group consisted of 73 patients. Over follow–up, 6 patients (8.2%) had PR (age at first eye findings: mean = 13.7y, median = 13y, range = 9–18y), 18 patients (24.7%) had NPR, and 49 patients (67.1%) had no retinopathy. The hemoglobin SB–Thalassemia group consisted of 27 patients. Over follow–up, no patients had PR, 3 patients (11.1%) had NPR, and 24 patients (88.9%) had no retinopathy. In all genotypes, the survival rates for time to retinopathy based on age, sex, and presence of systemic manifestations were not statistically significant. Both sex and presence of systemic manifestations had no statistically significant association with presence of retinopathy in any group (SS: p=0.2564 and p=0.1293; SC: p=0.5617 and p=0.7856; SB–Thalassemia: p=0.5350 and p=1.000, respectively).
Conclusions: :
Proliferative retinopathy is a rare event in the pediatric sickle cell patient population that is more common in the hemoglobin SC genotype. In this group, patients can demonstrate clinically significant retinopathy as early as 9 years and more commonly at an age of about 13 years. We recommend SC patients be referred for full ocular examination at age 9 years and be followed annually. For the hemoglobin SS and SB–Thalassemia genotypes, PR is more rare, and so patients can be referred for ocular examination at a later age (13–16 years) and followed biennially. Sex and presence of systemic manifestations do not seem to be associated with presence of retinopathy.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • retina