A 75 year old patient presents with deterioration of vision. On examination the pupillary reflex is observed to be sluggish and the Intraocular pressure is normal. Optic disc evaluation shows a large and deep cup and primarily shows paracentral scotomas. The most likely diagnosis is:

B i.e. Normal Tension Glaucoma - Primary open angle glaucoma (POAG) or chronic simple glaucoma (CSG) is commonest type of glaucoma that presents with bilateral, adult onset increased KW (>21 mm Hg), open angle (on gonioscopy), optic nerve damage (large & deep cup = cupping) and visual field defects (scotomas). Thin cornea is a known risk factorQ. - All features of POAG in a patient with normal/low intraocular tension (i.e. 21 mm Hg) suggest the diagnosis of normal tension glaucoma (NTG) or low tension glucomaQ. Glucoma patients may have sluggish/absent papillary reflexQ.