Inclusion Criteria:

1. Male or female, of legal age of consent.
2. Diagnosis of ocular hypertension (OHT) or glaucoma (incl. open angle glaucoma, chronic angle closure glaucoma, exfoliative glaucoma, pigmentary glaucoma or pseudophakic glaucoma) and requiring administration of IOP lowering eye drops.
3. Written informed consent has been obtained.
4. The patient can understand all study instructions, and is willing and able to comply with the schedule of visits and treatment.
5. Patient has been administering latanoprost eye drops as monotherapy in affected eye(s) for at least 12 weeks according to the approved product labeling.
6. Patient’s Day 0 IOP > 18 mm Hg in the proposed study eye/s on established latanoprost therapy.
7. Patients who have used COMBIGAN® Ophthalmic Solution in the past must not have been discontinued from using this medication due to adverse events or due to lack of efficacy.
8. Day 0: negative urine pregnancy test for females of childbearing potential.

Exclusion Criteria:

1. .Uncontrolled systemic disease (e.g., hypertension, diabetes).
2. .Females who are pregnant, nursing, or planning a pregnancy, or females of childbearing potential who are not using a reliable means of contraception. A female is considered of child-bearing potential unless she is post-menopausal, without a uterus and/or both ovaries, or has a tubal-ligation.
3. .Known allergy or hypersensitivity to the study medication or components.
4. .Anticipated alteration of existing chronic therapy with agents which could have a substantial effect on IOP (including, but not necessarily limited to systemic adrenergic agents including beta-adrenergic blocking agents [e.g., propanolol, metoprolol, nadolol, timolol and atenolol]), substantial interaction with study medications, or interaction with study outcomes.
5. .Corneal abnormalities that would preclude accurate IOP readings with an applanation tonometer.
6. .Any other active ocular disease other than glaucoma or ocular hypertension (e.g., uveitis, ocular infections, or severe dry eye). However, patients with chronic mild blepharitis, cataract, age-related macular degeneration, or a background diabetic retinopathy can be enrolled at the discretion of the investigator.
7. .Required chronic use of other ocular medications during the study other than the study medications. Occasional use of artificial tears or topical decongestants and/or antihistamine is acceptable. Use of these within 24 hours of a scheduled study visit is prohibited.
8. .Ocular surgery within the past 3 months.
9. .Current enrolment in an investigational drug or device study or participation in such a study within 30 days of entry into this study.
10. .Patient has a condition or is in a situation which in the investigator's opinion may put the patient at significant risk, may confound the study results, or may interfere significantly with the patient's participation in the study,
11. .Day 0 - Significant ocular irritation.