Retinal changes in children and adolescents with sickle cell disease attending a paediatric hospital in Cairo, Egypt: risk factors and relation to ophthalmic and cerebral blood flow

Sickle cell disease (SCD) is characterised by occlusion of small blood vessels. This study aimed to assess retinal changes in patients with SCD and its correlation with time-averaged mean flow velocity (TAMV) in middle cerebral arteries (MCA) and ophthalmic arteries (OA). Sixty SCD patients (aged 318 years) attending a paediatric hospital in Cairo, Egypt, during March 2010 to November 2011, were compared with 30 healthy controls. All underwent clinical and fundus examination by indirect ophthalmoscopy, and assessment of TAMV in MCAs and OAs by transcranial Doppler, repeated 1 year later for those with conditional velocities. HbS/ was diagnosed in 32 patients and HbSS in 28; 50 patients had normal fundus and 10 had bilateral non-proliferative retinopathy. Risk factors for retinopathy included HbSS, age, previous stroke, non-compliant hydroxyurea (HU) therapy, frequency of sickling crises and HbS level. TAMVs were increased in MCAs, but not in OAs, in sicklers. TAMVs in MCAs and OAs increased with non-compliant HU therapy, previous stroke, age, frequency of sickling crises and level of HbS. No significant interhemispheric difference was found. Sickle retinopathy was correlated with TAMV in MCAs but not in OAs. A significant difference was found between initial and follow-up TAMVs in the MCAs, after 1 year of regular HU and transfusion therapy, in those with conditional velocities.