Glaucoma is the second leading cause of blindness among seniors in Canada. It is often associated with an elevated intraocular pressure (IOP), but its exact mechanism is still largely unknown. Some studies have shown a link between glaucoma and changes in the amount of oxygen in the veins of the eye. The study aims to compare the amount of oxygen in ocular veins among three different groups using a spectrophotometer. This instrument is linked to a camera and can measure the quantity of oxygen in the veins using different characteristics of the blood inside.

The groups of the study are: patients without glaucoma, patients suspected of glaucoma and patients newly diagnosed with glaucoma. The drug the investigators are using, Travoprost 0.004%, will only be administered to the groups suspected or diagnosed with glaucoma. Travoprost 0.004% is already approved for use in Quebec and is part of standard care. Ten patients will be recruited into each group for a total of 30 patients in this study. All patients for the suspected or diagnosed groups will be recruited from the Jewish General Hospital. Subsequently all testing will be done at the École d'optométrie, Université de Montréal

Inclusion Criteria:

• good systemic health
• irido-corneal angle open
• intraocular pressure more than 18 mmHg

Exclusion Criteria:

• having cardiovascular problem
• Hypertension or diabetes
• under systemic medication for high blood pressure
• had an ocular surgery in the past

6 month