Risk factors for visual impairment in patients with sickle cell disease in London.

Purpose: Dramatically improved health care in recent years has increased the life expectancy of patients with sickle cell disease (SCD) as well as the prognosis for its ocular complications. We sought to identify risk factors for visual impairment in patients with SCD in London 4 decades after Goldberg's seminal studies. Methods: Patients 16 years and older with SCD (genotypes HbSS, HbSC, HbS beta-thalassemia) attending hematology and ophthalmology services were offered ocular examination. Retinopathy was graded according to the Goldberg classification. Visual impairment was defined as corrected distance visual acuity of 20/40 or poorer. Results: In total, 182 eyes of 182 patients (mean +/- SD age, 37.2 +/- 12.8 years; female, 65.9%) were included. Women were significantly older than men (mean +/- SD age, 38.8 +/- 13.1 vs 34.2 +/- 11.8 years; p = 0.0174). There was no difference in mean age of each genotype group (p>0.15). Risk factors for sight-threatening proliferative sickle retinopathy (PSR) were age over 35 years (odds ratio [OR] 2.01; 95% confidence interval [CI] 1.05-3.89; p = 0.0359) and HbSC genotype (OR 4.06; 95% CI 2.07-7.98; p<0.0001). Although visual impairment was related to the presence of sight-threatening PSR (OR 7.23; 95% CI 1.50-35.0; p = 0.0138), it was not related to hemoglobin genotype (p>0.50). Conclusions: We present the largest study of ocular findings in SCD in the United Kingdom. Sight-threatening PSR is a risk factor for visual impairment, but hemoglobin genotype status is not.