According to the World Health Organization (WHO), glaucoma is the leading cause of blindness in the world, second only to cataracts, and is considered the principal cause of irreversible blindness worldwide[1] The histological hallmark of glaucoma is accelerated loss of retinal ganglion cell layer (GCL) [2] Loss of GCL layer results in thinning of the retinal nerve fiber layer (RNFL) [3] topographical changes to the optic nerve head and a reduction in visual field sensitivity, which can ultimately result in visual impairment and blindness. Glaucomatous damage to the optic nerve head and RNFL can be quantified by different techniques.

In this study we have compared different diagnostic techniques i.e peripapillary RNFL loss Vs perimacular GCL thinning Vs VF. We concluded that VF remains the gold standard for diagnosing glaucoma and the peripapillary RNFL thickness on OCT remains the diagnostic test of choice for glaucoma suspect participants i.e. preperimetric glaucoma patients (before perimetry changes occurs). The diagnostic ability of perimacular GCL parameters is similar to that of peripapillary RNFL parameters in perimetric glaucoma i.e mild defect participants.