To evaluate ocular hypotensive efficacy and safety of Netarsudil (AR-13324) Ophthalmic Solution compared to Timolol Maleate Ophthalmic Solution.

Inclusion Criteria:

1. 18 years of age or older
2. Diagnosis of open angle glaucoma or ocular hypertension in both eyes
3. Post-washout intraocular pressure >20mmHg and <30mmHg in 1 or both eyes at 2 qualification visits
4. Corrected visual acuity equivalent to 20/200
5. Able to give informed consent and follow study instructions

Exclusion Criteria:

1. Clinically significant ocular disease
2. Pseudoexfoliation or pigment dispersion component glaucoma, history of angle closure or narrow angles
3. Unmedicated intraocular pressure ≥30mmHg
4. Use of more than 2 ocular hypotensive medications within 30 days of screening
5. Known hypersensitivity to any component of the formulation
6. Previous glaucoma surgery or refractive surgery
7. Ocular trauma within 6 months prior to screening
8. Any ocular surgery or non-refractive laser treatment within 3 months prior to screening
9. Recent or current ocular infection or inflammation in either eye
10. Used ocular medication in either eye of any kind within 30 days of screening
11. Mean central corneal thickness >620µm at screening
12. Any abnormality preventing reliable applanation tonometry of either eye
13. Clinically significant abnormalities in lab tests at screening
14. Known hypersensitivity or contraindication to beta-adrenoceptor antagonists
15. Clinically significant systemic disease
16. Participation in any investigational study within 60 days prior to screening
17. Used any systemic medication that could have a substantial effect in intraocular pressure within 30 days prior to screening
18. Women who are pregnant, nursing, planning a pregnancy or not using a medically acceptable form of birth control