The purpose of this study is to compare the efficacy and safety of the preservative-free fixed tafluprost-timolol combination to those of tafluprost and timolol alone. This study will enroll patients who have ocular hypertension or glaucoma and who are using timolol or prostaglandin.

The study medication period is 6 months, but the primary evaluation of efficacy is done at 3 months.

Inclusion Criteria:

• Aged 18 years or more
• A diagnosis of ocular hypertension or open-angle glaucoma and prior use of timolol or prostaglandin.
• Meet specific IOP level at visit 1 (screening), visit 2 (run-in) and visit 3 (baseline).
• Meet specific visual acuity score
• Are willing to follow instructions
• Have provided a written informed consent

Exclusion Criteria:

• Females who are pregnant, nursing or planning pregnancy
• IOP of 35 mmHg or greater
• Diagnosis of angle-closure glaucoma or secondary glaucoma other than capsular or pigmentary glaucoma in either eye
• Suspected contraindication or hypersensitivity to study medications tafluprost or timolol (e.g. asthma, low pulse)or to wash-out medication brinzolamide
• Glaucoma filtration surgery or any other ocular surgery (including ocular laser procedures) within 6 months prior to Screening
• Use of contact lenses at Screening or during the study
• Presence of any abnormality or significant illness that could be expected to interfere with the patient safety or study parameters
• Current participation in another clinical trial within the last 30 days