To evaluate safety and the ocular hypotensive effect of STN1012600 ophthalmic solution 0.002% alone or in combination with Timolol ophthalmic solution 0.5% for 52 weeks in subjects with open angle glaucoma or ocular hypertension.

Inclusion Criteria:

• 18 years of age or older.
• Diagnosis of OAG or OHT in both eyes, or one eye with OAG and the other with OHT.
• Corrected Visual Acuity of +0.60 logMAR (Decimal visual acuity 0.3) or better in each eye.

Exclusion Criteria:

• Presence of any active severe external ocular disease, inflammation, or infection of the eye and/or eyelids in either eye.
• History of severe ocular trauma in either eye.
• Any condition that prevents clear visualization of the fundus in either eye.
• Known allergy, hypersensitivity or contraindications to any components of the study medications or other study related procedures/medications.
• History of ocular surgery specifically intended to lower IOP in either eye.
• History of keratorefractive surgery in either eye.
• Females who are pregnant, nursing, or planning a pregnancy.
• Subjects with known or suspected drug or alcohol abuse.
• Participation in other investigational drugs or device clinical trials within 30 days prior to Screening.
• Any decision by the Investigator to terminate a subject in screening or declare any subject ineligible for any sound medical reason.