In this clinical trial, two groups of patients with primary open angle glaucoma (intraocular pressure [IOP] between 21 and 30 mm Hg) are included. Each group contains 44 patients who are older than 16 years. Exclusion criteria include the use of topical and systemic carbonic anhydrase inhibitors and IOP > 30 mm Hg. One group will randomly receive 2% dorzolamide eye drops three times a day and the other group will randomly receive 0.005% latanoprost eye drops once a day. Examinations include manifest refraction using an auto-refractometer (average of three readings), best-spectacle corrected visual acuity with full-correcting glasses using Snellen chart, IOP measurements using Goldmann Applanation tonometer, slit lamp biomicroscopy of cornea and anterior chamber, non-dilated funduscopy, and automated perimetry (Humphrey perimetry). Central corneal thickness (CCT), anterior chamber depth (ACD), and lens thickness (LT) will be measured using IOLMaster. The measurements by IOLMaster as well as refraction will be repeated after the instillation of cyclopantolate eye drops.
Two weeks after the initiation of anti-glaucoma medications, all above mentioned examinations will be repeated at least 2 hours after the use of drops. To evaluate the long-term effects, these measurements will be performed 6±1 weeks afterwards. The participants will have an access to the examiner whenever they have blurred vision. A statistical analysis will be used to compare the study groups in terms of any significant differences in refraction, CCT, ACD, and LT as well as to find any correlation between the use of each medication and blurred vision.