The Canadian Pseudoexfoliation Glaucoma Study 1 is a randomized clinical trial that aims to compare two initial treatment options - Selective Laser Trabeculoplasty (SLT) and Phacoemulsification (PHACO) - in newly diagnosed patients with pseudoexfoliation and need to lower the intraocular pressure. Patients with pseudoexfoliation and a recent decision to lower the intraocular pressure, who also have early asymptomatic lens opacification will be recruited and randomized to receive either SLT or PHACO. Patients will be followed for 2 years according to a target IOP protocol based on the Canadian Ophthalmological Society Glaucoma guidelines. Patients who do not achieve the target IOP with the initial randomization procedure will receive IOP lowering medications. The main outcome of interest will be the proportion of subjects who need IOP lowering medications after 2 years. Secondary outcomes include IOP reduction, time to need medications, patient reported outcomes in terms of visual function, and occurrence of adverse effects. To obtain longer follow-up information beyond two years, a chart review will be done 5 and 10 years after randomization.

Inclusion Criteria:

1. Pseudoexfoliation syndrome, detected at slit-lamp examination by exfoliative material on anterior capsule, pupil, or anterior chamber angle
2. Clinical decision to lower the IOP, as assessed by the investigator who is treating the subject, based on the presence of PXG or with IOP elevated enough to warrant treatment, even without clear evidence of optic nerve damage or visual field defect
3. Presence of asymptomatic early cataract

Exclusion Criteria:

1. Age less than 50 years old
2. Anterior chamber angle closure at gonioscopy, defined as pigmented trabeculum visible in less than 180º
3. Previous IOP lowering procedure such as trabeculoplasty, trabeculectomy, or minimally invasive glaucoma surgery
4. Previous use of IOP lowering medication for more than 6 months
5. Presence of ocular or systemic pathology or medication that could significantly influence the IOP, such as: uveitis, neovascular or traumatic glaucoma, corneal pathology influencing tonometry, use of oral steroids
6. IOP at baseline visit higher than 36 mmHg
7. Visual field damage at baseline visit with mean deviation worse than -15 dB
8. Not able or willing to provide voluntary, informed consent to participate in the study