Evaluation of Myopia as a Risk Factor for Glaucoma

Background Several factors including myopia has been attributed as a risk factor for the development of glaucoma. However the exact relationship between myopia and glaucoma still remains unanswered. Methods Subjects with any myopia (-1.0 diopter [D]) were identified by a standardized subjective refraction and categorized into low myopia (less than 2D) or moderate (greater than2D - 6D) and high myopia (greater than6D) over a period of 6 months. IOP was estimated using Goldman applanation tonometry. Anterior chamber angle assessment was done using Van herick technique in all patients and Gonioscopy in selected pateints. Glaucoma was diagnosed from characteristic visual field loss, combined with optic disc cupping and rim thinning. Result Of the 200 eyes of 100 patients enrolled on this study 18 % (36 eyes) had established glaucoma. While a large proportion of study group (84 %) had suspicious disc changes in the form of increased Cup Disc Ratio (CDR), notching and thinning of neuroretinal rim, 18 % had corresponding Visual field changes.10 % patients had IOP outside normal limits. Conclusions This study has confirmed myopia as a risk factor for glaucoma. Hence it is beneficial to screen patients with myopia at regular intervals for progression into glaucoma.