Scanning Laser Doppler Flowmeter Study of Macular Retinal Blood Flow of Healthy Volunteers and ERM patients

Abstract

Abstract: : Purpose:To compare the inter– and intraocular differences of capillary perfusion, and the intraocular regional differences of retinal blood flow in the macular area of healthy volunteers and idiopathic epiretinal membrane (ERM) patients.Methods:Tissue blood flow in the macula was examined in both eyes of 20 healthy volunteers (Experiment 1) and 20ERM patients before and after surgery (Experiment 2) with the Heidelberg retina flowmeter (HRF, Heidelberg Engineering Gmbh, Heidelberg, Germany). Blood flow measurements were made in a 10 x 2.5 degree area superior and inferior to the macula. The mean blood flow (MBF) was calculated by an automatic full–field perfusion image analyzer program. The MBF in the right and left eyes and in the superior and inferior macular areas of the same eye was compared. In ERM patients, blood flow was examined before and 1, 3, 6, and 12 months after vitrectomy.Results:Experiment 1:The ratios of the MBF in the right eye to the left eye were 1.00, and 1.03, respectively. The ratio of the MBF in the superior macular area to the inferior area was 1.01 for the right eyes, and 1.04 for the left eyes. Experiment 2: The ratios of MBF in the superior area before and 1, 3, 6, and 12 months after surgery were 0.73, 0.51, 0.76, 0.88, and 1.01, respectively. The ratios of MBF in the inferior area at each period were 0.70, 0.52, 0.75, 0.93, and 0.98, respectively.Conclusions:Because no significant differences were found in the MBF between the two eyes and between the superior and inferior macular areas in the same eye of healthy volunteers, interocular (e.g., affected eye vs. fellow eye) and intraocular (superior vs. inferior macular areas) comparisons of MBF can be made to determine if changes in retinal perfusion have occurred. Eyes with ERM showed abnormal hemodynamics in the macula that gradually improved after vitrectomy to a status comparable with the MBF of the normal fellow eye.

Keywords: imaging/image analysis: clinical • blood supply • vitreoretinal surgery