Sickle cell retinopathy and other chronic complications of sickle cell anemia: A clinical study of 84 Sub-Saharan African cases (Cameroon).

OBJECTIVE: Sickle retinopathy is a severe complication of sickle cell disease than can lead to blindness. We aim to describe the epidemiology of sickle retinopathy in homozygous sickle cell (SS) African patients and to analyze its association with non-ophthalmologic disease complications of sickle cell anemia. METHODS: We conducted a nested study within the CADRE cohort in Cameroon. Eighty-four consecutive SS outpatients, aged 10 years and older, with no visual symptoms, underwent an ophthalmologic examination. Mean age was 23±10 years. Clinical and biological features were compared between patients with and without sickle retinopathy. We compared the prevalence of the clinical complications and main biological characteristics in patients with and without sickle retinopathy using a univariate logistic regression. The same analysis was used to compare the patients with non-proliferative sickle retinopathy to those with proliferative sickle retinopathy. Statistical analyses were done using the R software (version 3.1.2). RESULTS: Fifty-two patients (62%) displayed sickle retinopathy, among them 23 (27%) had a non-proliferative sickle retinopathy, and 29 (35%) had proliferative sickle retinopathy. Patients with proliferative sickle cell retinopathy had a mean age of 28±11 years. Sickle retinopathy was associated with higher hemoglobin level (P=0.047) and fewer leg ulcers (P=0.018). Proliferative SR was associated with increasing age (P=0.008) and male sex (P=0.025) independently of the hemoglobin level. CONCLUSIONS: Sickle retinopathy is particularly frequent in sub-Saharan sickle cell SS patients, which advocates for early systematic screening.

[Prevalence and risk factors for sickle retinopathy in a sub-Saharan comprehensive Sickle Cell Center]. / Prévalence et facteurs de risque de la rétinopathie drépanocytaire dans un centre de suivi drépanocytaire d'Afrique subsaharienne.

INTRODUCTION: Retinopathy is a chronic complication with severe functional consequences in patients with sickle cell disease. Its prevalence is not well known in sub-Saharan Africa because of the absence of screening. We report here the results of a routine screening for sickle retinopathy in a Comprehensive Sickle Cell Center in Sub-Saharan Africa. METHODS: Screening of sickle retinopathy was carried out in all sickle cell patients aged 10 and over, followed between 2010 and 2012. Retinopathy was screened by dilated indirect fundoscopic examination and retinal angiography, if necessary. The gender, age and hematological parameters of patients with sickle retinopathy were compared with those of controls randomly selected from the cohort of sickle cell patients without retinopathy followed during the same period. RESULTS: The overall prevalence of sickle cell retinopathy was 8.8% (142/1604): 12.4% (91/731) in SC, 5.2% (38/734) in SS, 9.4% (5/53) in Sß°-thalassemia patients and 9.3% (8/86) in Sß+-thalassemia patients. Proliferative retinopathy was more common in SC patients (P<0.01). High levels of hemoglobin or of hematocrit were associated with retinopathy in all patients and with proliferative retinopathy in SC patients. In SS or Sß0thalassemia patients, high leukocyte count was associated with proliferative retinopathy. Low fetal hemoglobin level was associated with retinopathy in all groups. CONCLUSION: The prevalence of sickle cell retinopathy is high and negatively associated to the level of fetal hemoglobin. The efficiency of a routine screening for sickle cell retinopathy must be assessed in Africa as well as the benefit of phlebotomy and hydroxyurea therapy as a preventive treatments.