Ocular perfusion pressure: distribution and its relationship with glaucoma

Background and Objectives: Glaucoma is the second largest causative factor for blindness globally. Despite this, its pathogenesis remains obscure owing to its multi-factorial nature. This study aimed to analyse the distribution of the ocular perfusion pressure (OPP) and assessed its relationship with patients diagnosed with glaucoma along with other noted risk factors. Methods: This cross-sectional study was conducted among 284 subjects above the age of 40 years screened during rural medical camps. All participants underwent a comprehensive eye examination, following which the intra ocular pressure (IOP) was measured using the Shiotz tonometer and blood pressure (BP) was recorded. The IOP of patient’s right eye was used to calculate mean ocular perfusion pressure (MOPP). Welsh’s t-test and Chi-square tests examined the relationship between MOPP and glaucoma diagnosis at p < 0.05 significance. Results: A significant decrease in the MOPP was observed among glaucoma patients (45.61±12.89 mm Hg) in comparison to normal subjects (p < 0.05). In addition, the mean of systolic perfusion pressure (SPP) was found to be significantly higher among subjects with glaucoma (101.55±27.72 mm Hg, p < 0.05). Similarly, Diastolic perfusion pressure (DPP)on average was significantly higher in subjects with Glaucoma (51.85±17.45mm Hg,p< 0.05). The odds of having glaucoma was 3.284024 (Confidence Interval: 1.4250892-7.567802) times more when diabetes was involved. Conclusion: Low mean values of OPP, SPP and DPP are all independent risk factors for glaucoma, thereby providing further evidence of the vascular mechanism involved in multi-factorial pathogenesis of glaucoma