Haematological factors associated with proliferative retinopathy in homozygous sickle cell disease.

Haematological indices were investigated in 261 patients with homozygous sickle cell disease, 29 of whom had developed proliferative sickle retinopathy (PSR). After allowing for age-related effects, male patients with high Hb (> 9 g/dl) and low HbF (< 5%) levels appeared to constitute a high risk group for PSR. This relationship was not evident in females, PSR being observed in patients with lower Hb and higher HbF levels than in the male group. PSR occurred in 14% of patients aged 40 years or over in this sample.