Comparative study of refractive error patterns in leukemia patients and controls in Lagos, Nigeria

Abstract

Aim: To compare the ocular status of leukemics with controls in two tertiary hospitals. This paper focuses more on refractive status as other ocular findings have been reported elsewhere in detail. Materials and Methods: Forty newly diagnosed Patients with Leukemia were recruited and compared with 40 age/sex matched controls (non-leukemics) (80 eyes in each arm). Ocular statuses, including refraction, were assessed. Results: The leukemia was of both acute and chronic variety. Lymphoid, myeloid and bi-phenotypic expressions were seen. Cases presented with various forms of leukemic retinopathy, such as Retinal infiltrates, Roth Spots, perivascular sheathing, Retinal vascular tortuosity, intraretinal hemorrhages and cotton wool spots. None of these were found in controls 54(67.5%) eyes of cases had hypermetropia, (1+Diopter or more) as compared with only 6 of (7.5%) of controls. Patients with leukemia were twenty-five times more likely to develop hypermetropia (OR 25.6, 95% CI 9.8-66.5, p<0.0001). It is postulated this may be due to choroidal infiltration and thickening, with consequent hyperopic shift. Contrarily, there were thrice as many myopes in the control group. Conclusion: This study suggests that hypermetropia is highly likely to develop in patients with leukemia patients and may serve as a marker of disease. A larger study to include axial length measurements, choroidal thickness and central retinal thickness may help to elucidate the mechanism of the hyperopic shift.