Inclusion Criteria:  Greater than 18 years old. Have been diagnosed and treated for bilateral open-angle glaucoma or ocular hypertension in both eyes. Currently and for at least 30 days prior to screening, are being treated with a stable dose of latanoprost ophthalmic solution or prostaglandin analog for which there is a documented and positive treatment response with either agent maintained within both eyes. Have best corrected visual acuity (BCVA) via Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity (VA) score +0.6 logarithm of the minimum angle of resolution (logMAR) or better in each eye. At Visit 1, have IOP on prostaglandin or prostaglandin analog single therapy ≤ 21mmHg, at Visit 2, have diurnal IOP between 22 and 30 mmHG, inclusive for each eye. In the Investigator's judgment, are able to safely discontinue current ocular hypotensive medication during the washout period. Willing and able to avoid wearing contact lenses from Visit 1 (Screening) and for the duration of the trial. Willing and able to self-administer or have an able person available on a daily basis to assist with administration of study medication. Female subjects must either be incapable of pregnancy because of bilateral oophorectomy, hysterectomy, or bilateral tubal ligation, or be post-menopausal (have been amenorrheic for at least 2 years) or must use an effective (e.g., double-barrier) method of birth control for the duration of the study. Female subjects of childbearing potential must have a negative pregnancy test and not be nursing. Willing and able to comply with all study procedures.  Exclusion Criteria:  Causes of glaucoma other than primary open-angle glaucoma, including:  narrow angles (3 quadrants with less than Grade 2 according to Shaffer anterior chamber angle grading system) and subjects with angle closure clinically significant peripheral anterior synechiae congenital glaucoma a history of angle closure in either eye aphakic glaucoma traumatic glaucoma neovascular glaucoma pigmentary glaucoma pseudoexfoliative glaucoma drug-induced glaucoma Using a multi-drop treatment (other than prostaglandin or prostaglandin analog) for IOP-lowering medications. Advanced glaucoma or subjects with a cup/disc ratio greater than 0.8. Have undergone incisional IOP-lowering surgeries a placement or removal of minimally invasive glaucoma implant (MIG) in either eye. Have undergone non-incisional IOP-lowering surgeries within the past 6 months. Used anti-vascular endothelial growth factor (anti-VEGF) within 12 months of screening. Used intraocular, periocular or topical corticosteroids within 60 days of screening. Have received laser surgery for glaucoma (selective laser trabeculoplasty [SLT] or argon laser trabeculoplasty [ALT]) within 6 months of screening. Have uveitis, iritis or congenital aphakia. Are unwilling to discontinue current glaucoma medication within 30 days of the randomization (Visit 2). Have had intraocular or periocular surgery within the past 3 months. Are non-responsive to topical prostaglandins, prostamides or prostaglandin analogs in the Investigator's judgement. History of previous complicated cataract surgery, or previous refractive keratotomy in either eye. Used miotics and oral/topical carbonic anhydrase inhibitors within 5 days of screening. Have any known hypersensitivity to any components of the formulation or latanoprost. Have participated in a clinical trial for IOP-lowering investigational product or exposure to an IP within the prior 30 days. In the judgement of the Investigator, have previous or currently active clinically significant systemic or ocular disease in either eye that could affect study outcome.