Glaucoma Open angle glaucoma 2012-09-10T05:17:24Z A type of glaucoma defined by an open, normal appearing anterior chamber angle and raised intraocular pressure, HP:0012108 SNOMEDCT_US:77075001 UMLS:C0339573 Primary open angle glaucoma Evidence of optic nerve damage can include s optic disc abnormalities (Vertical cup:disk ratio over the 97. 5th percentile in the normal population), visual field defects. The role of increased intraocular pressure (IOP) in glaucoma is debated, but an IOP exceeding the 99. 5th percentile of the normal population may be considered to support the diagnosis.