Severity of Proliferative Sickle Cell Retinopathy Associated With the Clinical and Laboratory Factors inPatients With Sickle Cell Homozygous Sickle Cell (SS) and Hemoglobin C (SC) Disease

Purpose:Sickle cell disease (SCD) is among the most common, life-threatening monogenic disorders in the world. Proliferative sickle cell retinopathy (PSCR) is the most frequent vision-threatening complication of sickle cell disease (SCD). We studied the relationship between the severity of sickle cell retinopathy in heterozygous (SC) or homozygous (SS) adult SCD patients and the clinical and laboratory data obtained during visits to a national SCD referral center. Methods:Retrospective longitudinal analysis included 942 SCD patients (313 patients with SC and 629 with SS disease) with ophthalmologic evaluations who were followed over a 19-year period by a multidisciplinary team in a referral center. Goldberg classification was used to gratuate PSCR. We identified patient and SCD characteristics associated with sickle cell retinopathy severity using multinomiallogistic-regression models. Results:Multivariate analysis associated severe PSCR forms (stages III-V) with older age (p = 0.032), pulmonary involvement (documented pulmonary hypertension with pulmonary arterial pressure ≥ 40 mm Hg, restrictive syndrome > 20%, or previous history of pulmonary embolism diagnosed by vascular imaging) (p = 0.029), deafness or tinnitus (p = 0.026), and no history of osteomyelitis (p = 0.013) for SC patients; and with older age (p < 0.001), male sex (p = 0.003), andacute pyelonephritis (p = 0.04) for SS patients. Conclusions:The model of severe PSCR versus no PSCR showed good calibration and discrimination for SC and SS patients. Analysis of this large SCD population enabled us to establish several significant associations between retinal features of PSCR and other clinical features of SCD. Awareness of the clinical and laboratory factors significantly associated with severe PSCR in patients with SC or SS SCD may contribute to improved preventive strategies. Prospective studies are needed to establish a clinical scoring system that can predict with acceptable sensitivityand specificity the risk of developing severe PSCR.