The purpose of this study is to determine if location of laser peripheral iridotomy (LPI) that is the standard of care treatment for angle closure glaucoma is related to changes in post-operative intraocular pressure (IOP), endothelial cell count,anterior chamber angle morphology and onset of new visual disturbances.

Study hypothesis: Location of laser peripheral iridotomy affects occurrence of post-operative dysphotopsia symptoms, intraocular pressure, anterior chamber angle morphology and corneal endothelial cell count Study design: Multicenter randomized, prospective, single masked trial Trial setting: Hospitals Trial type: Treatment

Interventions: South Indian subjects aged 30 years or greater, with primary angle closure suspect (PACS) or primary angle closure/ primary angle closure glaucoma(PAC/PACG) will be randomized to either bilateral superior or nasal/temporal laser peripheral iridotomy. Subjects will undergo noninvasive testing and imaging studies to measure IOP, anterior chamber angle morphology and endothelial cell count and asked to answer a questionnaire at baseline and again at 2 weeks and 6 months after treatment Primary outcome measures: Occurrence of new self-reported general eye or dysphotopsia symptoms.

Secondary outcome measures: intraocular pressure, anterior chamber and anterior chamber angle morphology, endothelial cell count.

Inclusion Criteria:

• diagnosis of PACS or PAC/PACG in at least one eye

Exclusion Criteria:

• bilaterally pseudophakic
• prior iridotomy, iridoplasty, or incisional glaucoma surgery in either eye
• signs or symptoms consistent with acute angle closure at time of enrollment