The purpose of this study is to evaluate the effect on 24-hour IOP reduction of netarsudil-latanoprost fixed combination in one eye compared to latanoprost alone in the contralateral eye, dosed daily, 1 drop at night (QD, PM) in adult subjects, at least 18 years of age, with open angle glaucoma (OAG) or ocular hypertension (OHT).

This will be a double-masked, paired-contralateral, descriptive study to evaluate the effect on 24-hour IOP reduction of netarsudil-latanoprost fixed combination in one eye compared to latanoprost alone in the contralateral eye, dosed daily, 1 drop at night (QD, PM) in adult subjects, at least 18 years of age, with open angle glaucoma (OAG) or ocular hypertension (OHT). Study medication will be administered for 14 consecutive days, although the total time of subject participation in the study (including washout from prior treatment, if necessary) may be up to 10 weeks.

Inclusion Criteria

• Diagnosis of OHT or mild-to-moderate OAG in both eyes (OAG in one eye and OHT in the fellow eye is acceptable) based on VF, OCT and dilated fundus examination within one year of the screening visit.
• Both eyes must qualify for the study with an IOP of ≥18 mmHg but ≤34 mmHg on history or at the screening visit
• Be able and willing to provide signed informed consent and follow study instructions
• Ability to cooperate with the examinations required for the study and be able to attend all study visits
• If a contact lens wearer, willing to remove contact lenses at least 24 hours prior to each of the study visits.
• Best-corrected visual acuity (BCVA) using ETDRS chart of +0.4 logMAR units (Snellen equivalent ~ 20/50) or better in each eye

Exclusion Criteria

Ocular:

• Subjects with narrow angles (3 quadrants with Grade 2 or less according to Shaffer Scale), angle closure or a history of angle closure, or peripheral iridotomy in either eye
• Severe glaucomatous damage
• Difference in IOP between eyes > 4 mmHg (unmedicated) at any baseline time point
• Use of more than two ocular hypotensive medications within 30 days of screening
• Chronic or recurrent inflammatory eye diseases in either eye
• Ocular infection or ocular inflammation in the past 3 months in either eye
• Ocular trauma other than corneal abrasion within the past 6 months in either eye
• Clinically significant retinal disease (e.g., severe diabetic retinopathy, exudative or severe non-exudative macular degeneration, macular edema, retinal vein or artery occlusion) in either eye
• Cornea pathologic changes preventing reliable measurement (e.g., scarring, opacity, edema, keratoconus) in either eye
• Myopia greater than -6.00D, or hyperopia greater than +2.00D in either eye
• Central corneal thickness less than 480 μm or greater than 620 μm in either eye
• Previous intraocular surgery other than routine uncomplicated cataract surgery in either eye
• Previous glaucoma intraocular surgery or glaucoma laser procedures (except SLT performed more than 6 months ago) in either eye
• Unilateral intraocular surgery or glaucoma laser procedures
• Previous corneal refractive surgery in either eye (eg, radial keratotomy, PRK, LASIK, corneal cross-linking, etc.)
• Severe dry eye in either eye
• Use of ocular medications in either eye within 30 days of screening, with the exception of IOP-lowering medications (which must be washed out according to the provided schedule), and lubricating drops for dry eye (which may be used throughout the study)
• Known hypersensitivity to any component of the formulation (eg, benzalkonium chloride, etc.), or to topical anesthetic

Systemic:

• Clinically significant systemic diseases which might interfere with the study
• Participation in any interventional study within 30 days prior to screening visit
• Changes of systemic medication that could have an effect on IOP within 30 days prior to screening, or anticipated during the study including, β-adrenergic antagonists, α-adrenergic agonists and antagonists, angiotensin converting enzyme (ACE) inhibitors, angiotensin II receptor blockers
• Recent change in medications that are known to affect IOP within 30 days prior to the screening visit and during the study including: systemic/inhaled steroids, calcium channel blockers, diuretics, and vasodilators
• Women of childbearing potential who are pregnant, nursing, planning a pregnancy, or not using a medically acceptable form of birth control. An adult woman is considered to be of childbearing potential unless she is one year post-menopausal or three months post-surgical sterilization. All females of childbearing potential must have a negative pregnancy test result at the screening examination and must not intend to become pregnant during the study
• Subjects with a known hypersensitivity or contraindications to any of the ingredients in the study medications