Co-relation of spontaneous venous pulsations and ocular perfusion pressure in subjects with primary open angle glaucoma (POAG), normal tension glaucoma (NTG) and ocular hypertension (OHT) as compared

Introduction: Alteration in ocular perfusion pressure and increased venous resistance are known to be associated with glaucoma. Examination of spontaneous venous pulsations can be a surrogate method for assessing the circulation status of optic nerve head and retina. This study is aimed at assessing the prevalence of the spontaneous venous pulsation (SVP) over the optic disc in patients with open angle glaucoma and its co relation to ocular perfusion pressure. Aim: To analyze the co relation between the presence of spontaneous venous pulsations and ocular perfusion pressure in POAG, NTG, OHT and controls. Materials and Methods: This cross sectional, prospective study. Study period was conducted from September 2013 to June 2015. The study included 334 eyes of 167 patients, (52 patients POAG, 35 each in NTG, OHT and 45 in control group). Spontaneous venous pulsations (SVP) were observed on dilated fundus examination using slit lamp bio microscopy (frequency observed for 20sec) by two ophthalmologists who confirmed each other's findings. Blood pressure was measured in all these patients and ocular perfusion pressure was analysed. Statistical analysis: Data was analysed using SPSS 16.0 software. Univariate analysis was done. Results: SVP was absent in 64.4% of POAG (P<0.001) 15.7% of NTG (P=0.871), 10.3% of OHT (P=0.252) and 16.67% of controls. Correlation of mean ocular perfusion pressure and absence of SVP did not show any statistically significant association. Systolic perfusion pressure showed statistically significant co relation to absence of SVP in NTG (p=0.002), OHT (p=0.03). Diastolic Perfusion pressure and absence of SVP was significant in OHT group (p=0.03). Conclusions: Spontaneous Venous Pulsation has a predictive value as a surrogate method of assessing ocular blood flow, probably an indicator of vascular resistance in the pathogenesis of open angle glaucoma.