Prevalence of pre-perimetric primary open angle glaucoma in hypertensives of North India

Systemic hypertension is alleged to increase the risk of glaucoma. As clinically Primary Open angle Glaucoma (POAG) is diagnosed only after approximately 40% of ganglion cell loss has occurred, therefore this study was commenced with an aim to determine the prevalence of pre-perimetric glaucomatous damage and its association with systemic hypertension using optical coherence tomography (OCT).

A total of 680 study participants were enrolled in this cross-sectional study. Among them 340 patients were of systemic hypertension (Group 1) and 340 patients without hypertension (Group 2). All patients underwent detailed history, ocular and systemic examination including slit lamp examination, fundus examination by +90 D lens, Humphrey field analyser for field charting and OCT for nerve fiber analysis. For glaucomatous nerve damage.

Group 1 and Group 2 had Male: Female ratio of 1:8 and 1:9, respectively (P = 0.809). Maximum participants 48.8% and 54.4% in Group 1 and Group 2, respectively, were in age group 50-59 years. Statistically significant difference was seen in the percentage of pre-perimetric glaucomatous patients between the two groups (P < 0.001). On OCT analysis between pre-perimetric glaucomatous eyes and healthy eyes significant difference in thickness was seen in temporal inner macula, inferior outer macula, temporal outer macula, superior outer macula and nasal outer macula. Significant difference in volume was seen for inferior temporal and nasal outer macula (P < 0.001).

In hypertensives, glaucomatous optic nerve damage starts much earlier before the obvious clinical signs of POAG appear, as compared to normotensive individuals.