Abstract
Abstract: :
Purpose: To study the distribution of areas of low flow and the inter-eye and intra-eye blood flow relationships in a random sample of older individuals. Methods: Blood flow measurements were performed in both eyes of 240 subjects from a sample of 251 subjects (age 60-88 years, mean 70.5 years) participating in a population based study. 13 subjects with glaucoma, 6 with migraine and 6 under glaucoma medications were excluded form the analysis. Heidelberg retina flowmeter was used to record capillary perfusion in the superotemporal and inferotemporal peripapillary region in both eyes. Pixel by pixel analysis was done in an area adjacent to the optic disc, with a minimum of 1600 pixels. The percentage of pixels with no flow (0 pixels), mean flow, and 10, 25, 50, 75, 90 percentiles of flow values were calculated. Correlation analysis was done between right and left eyes, between superior temporal (ST) and inferior temporal (IT) flow values and between IOP, perfusion pressure (PP) and blood flow parameters. Results: IOP and PP were not significantly correlated with any of the blood flow parameters. Correlations between eyes (LE and RE) and between ST and IT. Conclusion: In normal individuals older than 60 years of age, there is a correlation in most of blood flow parameters in ST and in IT between the right and left eyes as measured with the HRF. Interestingly, there is no correlation in the low blood flow values between ST and IT in the same eye. Thus, there may be more differences in blood flow among the different regions of an eye than between two eyes of an individual. There may be a central regulatory mechanism that accounts for the observed association in blood flow in the same location between the two eyes of an individual.
Keywords: 331 blood supply • 309 aging • 432 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)