Ocular manifestations of sickle cell disease at the University Teaching Hospital, Lusaka, Zambia

Abstract

Background: Sickle cell disease (SCD) is an autosomal recessive haemoglobinopathy occurring due to a defect in the beta chain of the haemoglobin molecule. Its effects on the eye have been reported in the adnexa, anterior and posterior segments. An overall sickling prevalence in Zambia varies between 4.5-16.8% in a population of 13 million people but ocular manifestations have not been documented. Objective: To assess the pattern of ocular manifestations in sickle cell disease patients at the University Teaching Hospital (UTH), Lusaka, Zambia. Study design: Hospital- based prospective consecutive case series. Setting: Hospital wards and haematology clinic. Methodology: All patients aged between 6 to 61years reporting for routine follow up in the haematotology clinic and those admitted in medical wards during the period of the study were examined. A questionnaire was administered to extract information from patients reporting to the health facility. Examination of the eyes was done using slit lamp biomicroscope. The posterior segment was examined with an indirect ophthalmoscope and slit lamp biomicroscope. Results: Ocular abnormalities were found in 69.15% of the 94 subjects studied. All had HbSS with a female to male ratio of 1.8:1. Blindness was found in 1.09% of eyes examined, and was due to retinal detachment. Anterior segment findings included: conjuctival sickle sign 38 (40.43%); jaundice 18 (19.35%), iris atrophy 2 (2.13%); and cataract 2 (2.13%). Posterior segment findings included: vessel tortuosity 41 (44.09%); black sun burst 4 (4.30%); angiod streak 1 (1.08%); schisis 1 cavity2 (2.15%); macular hole1 (1.08%); epiretinal membranes membranes1 (1.08%). Retinal detachment was found in 1 (1.08%) patient. There was statistically significant association of ocular manifestation with age above 26 years (p=0.013). Conclusion: HBSS was the only genotype of SCD in this study. People originating from the Northern and Eastern regions had the highest prevalence of SCD. With regard to ocular manifestations of SCD, the prevalence was high but most of the manifestations were not causing visual impairment. Both men and women were equally affected. The prevalence increased with age.