Abstract
Abstract: :
Purpose: To identify alterations of retinal capillary blood-flow in the papilomacular area in preclinical diabetic retinopathy using the Heidelberg scanning laser Doppler flowmeter (HRF - Heidelberg Engineering, Dossenheim, Germany). Methods: Eleven eyes from eleven patients with type 2 diabetes and no lesions visible on fundus photography (level 10 of Wisconsin grading) and 10 eyes from 10 healthy subjects of similar age range were examined with the HRF. Intravisit reproducibility of retinal capillary blood-flow measurements was assessed in normal subjects and in type 2 diabetic patients comparing different measurement areas and different analysis procedures: 10x10 pixels box with original software, 10x10 pixels box with SLDF software, and whole scan analysis with SLDF software. Results: Intravisit reproducibility for the whole scan analysis in the papilomacular area was 3.6%, 4.9% and 4.6% for volume (VOL), flow (FLW) and velocity (VEL), respectively. Using this method, mean and SD values for retinal capillary blood-flow are of 13.25±2.87, 214.58±55.30 and 0.74±0.17, for VOL, FLW and VEL for healthy eyes, comparing with 18.55±7.00, 334.88±169.57 and 1.11±0.52 in eyes with preclinical diabetic retinopathy (p<0.001). Conclusion: The HRF shows acceptable reproducibility when using the whole scan analysis in the papilomacular area. Retinal capillary blood VOL, FLW and VEL were particularly increased in 5 of the 11 diabetic eyes examined, with values over the mean+2SD of the control population, suggesting that these eyes are at risk.
Keywords: 387 diabetes • 430 imaging/image analysis: clinical • 460 macula/fovea