Abstract
Abstract: :
Purpose: To explore the relationship between visual field performance and the pulsatile component of ocular blood flow in patients with diabetes mellitus. Methods: Patients were selected from a diabetic eye clinic and were excluded if there was a history of previous ocular surgery, photocoagulation therapy, grade 2+ cataract or vitreous haemorrhage. Visual field analysis (Zeiss Humphrey VFA II, SITA 24-2 program) and pneumatonometry (Ocular Blood Flow Analyzer, Paradigm Medical Ind, Utah, USA) were performed on one randomly selected eye of each patient. Systemic heart rate and arterial pulse pressure were also measured. Results: 51 consenting patients were recruited: mean age 59.9 y, SD 11.1 y; 38 male, 13 female. Of these, 10 had no retinopathy, 25 had background retinopathy and 16 had pre-proliferative or proliferative retinopathy. For the group, pulsatile ocular blood flow was significantly correlated with visual field mean defect: r = 0.305, p = 0.031. A simple correlation was not found between pulse amplitude and visual field mean defect: r = 0.182, p = 0.205. Stepwise multiple regression analysis found pulsatile ocular blood flow to be significantly correlated with visual field mean defect and arterial pulse pressure (p = 0.012). Stepwise multiple regression analysis found pulse amplitude to be significantly correlated with visual field mean defect, intraocular pressure, arterial pulse pressure and heart rate (p = 0.035). Factorial analysis found no significant difference in pulsatile ocular blood flow or pulse amplitude when the patients were divided into groups depending on retinopathy grade. Conclusion: Deteriorating visual performance in diabetes mellitus, as shown by increased visual field mean defect, is significantly associated with reduced pulsatile ocular blood flow. This may be due to a causative or consequential factor in the mechanism of visual loss.
Keywords: 331 blood supply • 387 diabetes • 624 visual fields