The purpose of the study is to determine the relationship of the intraocular pressure patterns recorded during 2 sessions using Triggerfish, before and after elective laser peripheral iridotomy in angle closure glaucoma patients.

Inclusion Criteria:

• Diagnosis of primary angle closure (PAC) or primary angle closure glaucoma (PACG) with indication for laser peripheral iridotomy (PAC is defined by the presence of a partial or complete iridotrabecular contact in more than 2 quadrants with either raised intraocular pressure [i.e. more than 21 mmHg] and/or primary adhesion to the trabecular meshwork (peripheral anterior synechiae [PAS]; however, with normal optic disc and visual field. PACG is defined by the presence of iridotrabecular contact with either raised intraocular pressure and/or PAS, and evidence of glaucomatous optic disc and visual field)
• No intraocular pressure-lowering drug treatment or a 4-week wash-out period prior to study day 0 and throughout the study
• Aged ≥18 years, of either sex
• Not more than 6 diopters spherical equivalent on the study eye
• Not more than 2 diopters cylinder equivalent on the study eye
• Have given written informed consent, prior to any investigational procedure

Exclusion Criteria:

• History of acute angle closure glaucoma
• Secondary angle closure glaucoma
• History of ocular surgery within the last 3 months
• History of ocular laser treatment, including previous laser peripheral iridotomy
• Corneal or conjunctival abnormality precluding contact lens adaptation
• Severe dry eye syndrome
• Patients with allergy to corneal anesthetic
• Patients with contraindications for silicone contact lens wear
• Patients not able to understand the character and individual consequences of the investigation
• Participation in other clinical research within the last 4 weeks