The association of ocular blood flow with haemorheological parameters in primary open‐angle and exfoliative glaucoma

Purpose: To evaluate the ocular blood flow velocities and haemorheological parameters in patients with primary open‐angle glaucoma (POAG), exfoliative glaucoma (XFG) and exfoliation syndrome (XFS) and to compare their results with those of healthy controls. Methods: Twenty‐five patients with POAG (group 1), 25 patients with XFG (group 2), 25 patients with XFS (group 3) and 25 healthy controls (group 4) were included in the study. Ocular blood flow velocities of ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (SPCAs) were measured using colour Doppler imaging (CDI). Haemorheological parameters (erythrocyte elongation and aggregation index, aggregation amplitude, aggregation half‐life, plasma viscosity, haematocrit) were measured in venous blood samples of all patients. Results: The peak systolic velocity (PSV) and end‐diastolic velocity (EDV) values were lower and resistive indices (RI) were higher for the OA, CRA and SPCA of glaucomatous (groups 1 and 2) patients compared with those of controls (group 4) (PSV: OA, 40.4 ± 11.3 versus 52.6 ± 12.8 cm/second, p < 0.001; CRA, 12.9 ± 2.9 versus 15.3 ± 4.2 cm/second, p = 0.02; SPCA, 21.7 ± 6.6 versus 26.6 ± 8.3 cm/second, p = 0.013) (EDV: OA, 10.3 ± 4.3 versus 14.2 ± 5.1 cm/second, p < 0.001; CRA, 3.7 ± 1.1 versus 4.5 ± 1.3 cm/second, p = 0.025; SPCA, 5.2 ± 1.8 versus 7.7 ± 3.2 cm/second, p = 0.001) (RI: OA, 0.75 ± 0.05 versus 0.66 ± 0.07, p < 0.001; CRA, 0.73 ± 0.08 versus 0.68 ± 0.10, p = 0.223; SPCA, 0.70 ± 0.10 versus 0.63 ± 0.11, p = 0.004). There were no statistically significant differences between the haemorheological parameters of glaucomatous and non‐glaucomatous patients. The reduction in ocular blood flow velocities in groups 1, 2 and 3 were not associated with changes in haemorheological parameters. Conclusion: Our results suggest that impairment of the retrobulbar blood flow in POAG and XFG is not associated with alterations in haemorheological parameters.