Correlation between ocular perfusion pressure and ocular pulse amplitude in glaucoma, ocular hypertension, and normal eyes

Abstract

BackgroundThe purpose of this study was to investigate the correlation between ocular perfusion pressure and ocular pulse amplitude in glaucoma, ocular hypertension, and normal eyes.MethodsNinety eyes from 90 patients were included. Thirty patients had been recently diagnosed with glaucoma and had no previous history of treatment for ocular hypotension, 30 had elevated intraocular pressure (IOP) without evidence of glaucoma, and 30 had normal IOP (<21 mmHg) with no detectable glaucomatous damage. Goldmann applanation tonometry (GAT), dynamic contour tonometry (DCT), blood pressure measurement, pachymetry, Humphrey visual field, and routine ophthalmic examination was performed in each patient. Ocular perfusion pressure was calculated as the difference between mean arterial pressure and IOP. The ocular pulse amplitude was given by DCT. The Pearson correlation coefficient was used to compare the glaucomatous and ocular hypertensive groups, and comparisons with the normal IOP group were done using the Spearman’s rank correlation coefficient.ResultsMean IOP by DCT was 22.7 ± 4.3 mmHg in the glaucoma group, 22.3 ± 2.8 mmHg in the ocular hypertension group, and 14.3 ± 1.6 mmHg in the control group. Mean IOP by GAT was 19.0 ± 5.1 mmHg for glaucoma, 22.4 ± 2.1 mmHg for ocular hypertension, and 12.9 ± 2.2 mmHg for controls. Mean ocular pulse amplitude was 3.4 ± 1.2 mmHg in the glaucoma group, 3.5 ± 1.2 mmHg in the ocular hypertension group, and 2.6 ± 0.9 mmHg in the control group. Mean ocular perfusion pressure was 46.3 ± 7.9 mmHg in the glaucoma group, 46.3 ± 7.9 mmHg in the ocular hypertension group, and 50.2 ± 7.0 mmHg in controls. No significant correlation between ocular perfusion pressure and ocular pulse amplitude was found in any of the groups (P = 0.865 and r = −0.032, P = 0.403 and r = −0.156, P = 0.082 and ρ = −0.307 for glaucoma, ocular hypertension, and normal eyes, respectively).ConclusionThere is no significant correlation between ocular perfusion pressure and ocular pulse amplitude values in glaucoma, ocular hypertension, or normal eyes. IOP values measured by GAT correlate with those measured by DCT.

Increase intra ocular pressure

“…For instance, a study by Klein BE et al demonstrated that BMI is positively associated with IOP, suggesting that obesity may contribute to elevated eye pressure, potentially due to increased episcleral venous pressure and resistance to aqueous outflow [13] . Similarly, the relationship between height and IOP, as highlighted in our results, is supported by findings from other research, such as the work by Hepsen IF et al, which posited that taller individuals tend to have deeper anterior chambers and, consequently, different IOP dynamics [14] . Age as a correlate of IOP further enriches the discussion.…”

Evaluation of ocular pulse amplitude in non-arteritic anterior ischaemic optic neuropathy

“…Kynigopoulos et al reported that low OPA was related to functional and structural damage in primary open angle glaucoma [21]. In contrast, the results of a study by Figueiredo et al, showed significantly lower mean OPA in the control group than in the patients with glaucoma or ocular hypertension [22]. …”

Choroidal changes after cardiopulmonary bypass

“…Ocular perfusion pressure (OPP) is defined as arterial blood pressure minus IOP. 15 Many factors, such as vascular resistance, blood oxygen levels and hypothermia, might affect OPP. 16,17 It was shown that retinal blood flow remains unchanged despite large alterations in OPP 18,19 .…”