The association of lower ocular perfusion pressure with glaucoma severity independent of intraocular pressure.

Purpose

To investigate the relationship between systemic hypertension, ocular perfusion pressure (OPP), and intraocular pressure (IOP) with glaucoma severity, with a secondary analysis on the impact of antihypertensive medication.

Design

Cross-sectional observational study.

Methods

A total of 75 patients (75 eyes) with primary open-angle glaucoma (POAG) were included. One eye per patient was randomly selected for analysis. All participants underwent comprehensive ophthalmic examination and a single time-point systemic blood pressure (BP) measurement. Data on antihypertensive medication usage were also collected. Glaucoma was staged as early, moderate, or advanced. Key variables included systolic/diastolic blood pressure (SBP/DBP), mean arterial pressure (MAP), IOP, and estimated OPP. Analysis of variance and Pearson's correlation were used. A sub-group analysis compared hemodynamic parameters between patients on antihypertensive medication and those who were not.

Results

The mean age was 53.99 ± 6.53 years. While mean IOP did not differ significantly across glaucoma stages ( P = 0.71), mean OPP (57.59 to 50.65 mmHg), diastolic perfusion pressure (DPP), DBP, and MAP all decreased significantly with increasing glaucoma severity ( P < 0.001). In a sub-group analysis, patients on antihypertensive medication ( n = 42) had a significantly lower mean OPP (53.21 ± 5.98 mmHg) compared to those not on medication (57.85 ± 5.89 mmHg; P = 0.002), despite having similar in-office SBP.

Conclusions

Lower OPP, DPP, DBP, and MAP were significantly associated with advanced glaucoma severity. Patients on antihypertensive medication had lower mean OPP, suggesting they may be at higher risk for perfusion-related damage not captured by in hospital BP readings. This highlights the importance of considering the hemodynamic effects of medication in glaucoma management.