Primary objective of this study is to study the efficacy of travoprost without preservatives in the treatment of glaucoma patients and to monitor the ocular surface.

This is a prospective study including patients visiting the outpatient glaucoma clinic of the University General Hospital of Alexandroupolis for their standard evaluation. Study population is already under treatment with a travoprost preparation without preservatives. They will be fully informed about the procedure and the purpose of the study and a written consent will be obtained. For every patient included in the study intraocular pressure will be measured using a Goldman applanation tonometer, according to the standard way of practice at our clinic. Also, Tear Break-Up-Time (BUT), conjunctival hyperemia grading and Schirmer testing will be used to assess the ocular surface state. Visual field tests and OCT RNFL measurements will also be obtained. The above measurements will be repeated 6 months after the initial examination.

Inclusion Criteria:

• Patients with glaucoma treated with travoprost without preservatives.

Exclusion Criteria:

• Co-administration of another anti-glaucoma preparation with or without preservatives, Sjogren's syndrome, poor eyelid occlusion of any etiology.

Adult glaucoma patients already under treatment with travoprost without preservatives.