[Evaluation analysis of blood flow of peripapillary area in glaucoma patients using scanning laser Doppler flowmetry]

Abstract

Purpose: To evaluate capillary blood flow and velocity in retinal peripapillary area in primary open angle glaucoma (POAG), normal tension glaucoma (NTG), pseudoexfoliation glaucoma (PEXG) and age matched control group (C) using scanning laser Doppler flowmetry (Heildelberg Retina Flowmeter).

Material and method: One randomly selected eye of 17 POAG patients (mean age 59.3 +/- 2.6), 18 NTG patients (mean age 56.4 +/- 2.4), 17 PEXG patients (63.3 +/- 2.8) and 15 healthy subjects (mean age 55.8 +/- 3.8) underwent examination with scanning laser Doppler flowmetry. The measurements were performed at the superior and inferior temporal peripapillary retinal area. The measured parameters were capillary blood flow and velocity of the moving erythrocytes. Each image was analysed using the program AFFPIA. This software calculates the hemodynamic parameter flow of each pixel. Comparison of value obtained from patients and control participants were made using Student's t test.

Results: Scanning laser Doppler flowmetry results showed a significant reduction in blood flow at the superior and inferior temporal peripapillary area in POAG and NTG patients compared to control group (p < 0.04). The POAG and NTG patients had also significantly decreased velocity at the inferior temporal peripapillary retinal area compared to control group. No statistical difference was found between blood flow and velocity in POAG compared with NTG. When compared with the control participants, patients with PEXG showed significant decreases in the mean blood flow at the inferior temporal quadrant (p < 0.05), while the differences in the mean flow and velocity at the superior quadrant between those groups were not statistically significant.

Conclusions: Our findings indicate a reduction in ocular blood flow at the temporal peripapillary retinal area in patients with POAG and NTG compared to age matched control participants. The peripapillary retinal microcirculation is not significantly altered in patients with PEXG compare with POAG and JNC. The blood flow parameters in the capillaries are lower in JNC retinas, the difference however is not significant. Further clinical investigation is required having groups homogeneous with respect to stage of glaucoma and controlled for factors known to effect perfusion pressure.