Changes in the retrobulbar hemodynamic parameters after decreasing the elevated intraocular pressure in primary open-angle glaucoma patients

Abstract

Introduction Ocular blood flow (OBF) disturbances could be involved both in the pathogenesis and in progression of glaucomatous damage. Objective The aim of the study was to compare the retrobulbar hemodynamic parameters in the ophthalmic artery (OA), central retinal artery (CRA) and short posterior cilliary arteries (SPCA) after decreasing the elevated intraocular pressure (IOP) in primary open-angle glaucoma (POAG) patients by using color Doppler imaging (CDI). Methods We examined 60 patients (21 male and 39 female) with diagnosed and treated POAG. Thirty-nine patients had increased IOP (>25 mm Hg). Peak-systolic velocity (PSV), end-diastolic velocity (EDV), Pourcelot resistance index (RI), and pulsatility index (PI) were assessed in the OA, CRA, and SPCA. IOP was measured both with the Goldmann Applanation tonometer (GAT) and with the Dynamic Contour tonometer (DCT), three times respectively. Ocular pulse amplitude (OPA) was measured using DCT. Results The retrobulbar parameters between the baseline and after IOP reduction showed no difference in measurements. After Bonferroni correction (p<0.0056, alpha/9) statistical significance was recorded only in the following retrobulbar hemodynamic parameters; DCT (29.8±6.2 vs. 15.5±5.0), GAT (33.8±9.0 vs. 15.0±6.6) and OPA measurements (4.3±1.0 vs. 3.0±1.6), as compared to the baseline. There was no correlation between the changes in IOP measured with either DCT or GAT and changes in the hemodynamic parameters (p>0.05 for all). Pearson correlation coefficient (95% CI) showed very good correlation for IOP measurements between DCT and GAT: at baseline 0.83 (0.71 to 0.90) and at the end 0.71 (0.55 to 0.83); p<0.0001 for both measurements, but without any difference between them (p>0.05). Conclusion There was a lack of correlation between the changes in IOP measured with either DCT or GAT and the changes in the hemodynamic parameters.