Distribution of ocular perfusion pressure and its relationship with intraocular pressure in patients with primary open angle glaucoma in Enugu, South East, Nigeria

Abstract

Background: Ocular perfusion pressure (OPP) has been suggested as a possible risk factor for the development and progression of primary open angle glaucoma (POAG). Aim: To determine the distribution of OPP and its relationship with intraocular pressure (IOP) in Nigerian patients with POAG.
Patients and Methods: A descriptive and comparative survey was adopted. A total of 120 subjects, 60 newly diagnosed POAG and 60 non‑glaucomatous (NG) subjects, aged 40 years and above, who attended the ophthalmic clinic of University of Nigeria Teaching Hospital Enugu were recruited over a six‑month period in 2019. All the subjects had ocular examination, blood pressure and IOP measurements. Statistical package for social sciences software version 25 was used for data analysis. Chi‑square test, independent samples t‑test, and Mann‑Whitney U test were used for comparison while Pearson correlation and simple linear regression were used to ascertain the relationship. A P value of <0.05 was considered significant.
Result: The mean age of the participants was 57.9 + 11.9 years. The mean OPP was found to be significantly lower in the POAG subjects (Right eye, R = 43.6 ± 12.6, Left eye, L = 41.9 ± 13.3) mmHg compared with the NG group (R = 53.9 ± 10.9, L = 53.7 ± 10.9) mmHg (p < 0.001 for both eyes). A significant inverse relationship was observed between OPP and IOP in POAG subjects (p < 0.001), while there was none in NG subjects. Conclusion: OPP was lower in POAG subjects than in NG subjects. The observed relationship suggests that reduced OPP may play a role in the development of POAG.