Macular capillary blood flow velocity by blue-field entoptoscopy in diabetic and healthy women during pregnancy and the postpartum period.

Abstract

To study macular capillary blood flow velocity in diabetic and healthy women during pregnancy and the postpartum period. A prospective study of 46 pregnant women with insulin-dependent diabetes and 11 healthy pregnant women was performed. Macular capillary blood flow velocity was measured by blue-field entoptic simulation. Diabetic retinopathy was graded from colour fundus photographs. In diabetic women, the macular capillary blood flow velocity was 0.94+/-0.27 mm/s (mean +/- SD) during the first trimester, 1.00+/-0.28 mm/s during the third trimester and 1.03+/-0.24 mm/s 3 months postpartum, compared with values of 0.71+/-0.20, 0.77+/-+/-0.20 and 0.82+/-0.19 mm/s, respectively, in healthy women (P=0.0026 between groups). Diabetic women with no or very mild retinopathy had lower macular capillary blood flow velocities than those with more severe retinopathy (P=0.0164), but higher velocities than healthy women (P=0.0167). An increase temporally from the first trimester to the postpartum period was observed in diabetic women (P=0.0294) but not in healthy (P=0.2449) women. According to our study macular capillary blood flow velocity is higher in diabetic than in healthy women during pregnancy and the postpartum period. Further, capillary blood flow velocity seems to depend on the grade of retinopathy in pregnant diabetic women. These data support the concept that capillary hyperperfusion may play a role in the development of diabetic retinopathy during pregnancy.