Pulsatile ocular blood flow in diabetic retinopathy

Purpose: To assess circulatory properties of eyes with progressive stages o f diabetic retinopathy, Methods: The intraocular pressure, pulse amplitude (PA) and pulsatile ocula r blood flow (POBF) were measured with a pneumatonometer (OBF Labs UK Ltd). The eyes were grouped: (a) normal control, n=26, (b) diabetes with no obse rvable diabetic retinopathy (NDR), n=18, (c) mild to moderate non-prolifera tive diabetic retinopathy (NPDR), n=20, and (d) very severe pre-proliferati ve and proliferative diabetic retinopathy (PPDR/PDR), n=12, Results: The PA and POBF values were lower than normal values in the earlie st stage (NDR). The POBF increased but was still below normal levels at the NPDR stage, and then increased to an above normal level in the PPDR/PDR st age of diabetic retinopathy. The PA was at normal levels in these later two stages. Conclusion An initial decrease in pulsatile ocular blood flow is present wi th the onset of diabetes where no diabetic retinopathy has yet occurred. Su bsequently, the pulsatile ocular blood flow increases with the severity of the retinopathy.