The purpose of this randomized, double-masked, parallel-group, multicenter study is to evaluate ocular surface effects after the administration of travoprost with SofZia® preservative system or Xalatan once daily for 12 weeks.

Inclusion Criteria:

• 18 years of age or older.
• Diagnosis of primary open-angle glaucoma (with or without pseudoexfoliation or pigment dispersion) or ocular hypertension in at least one eye (study eye).
• Use of BAK (benzalkonium chloride) containing intraocular pressure (IOP) lowering medication for a minimum of one year, including latanoprost (Xalatan®) monotherapy for at least 6 months prior to Visit 1.
• IOP controllable and stable on the study medication alone (both eyes).
• Believed to have ocular surface disease (OSD).
• Tear Break-up Time (TBUT) of ≤ 6 seconds in the study eye.
• Willing and able to discontinue the use of any topical ocular medication other than the study medication or BAK free artificial tears for the duration of the study.
• Other protocol-defined inclusion criteria may apply.

Exclusion Criteria:

• Current use or use within the last 3 months of cyclosporine ophthalmic emulsion 0.05% (Restasis®), topical ocular steroids, or topical ocular non-steroidal anti-inflammatory drugs.
• Current use of punctual plugs.
• Women of childbearing potential not using reliable means of birth control.
• Women who are pregnant or lactating.
• Suspected or diagnosed with Sjogrens's syndrome.
• Current use of any brand of artificial tears containing BAK.
• Use of any systemic medications on a chronic basis not on a stable dosing regimen for at least 30 days prior to Visit 1, or an anticipated change in dosing regimen of medications during the course of the study.
• Intraocular conventional surgery or laser surgery in study eyes less than six months prior to Visit 1.
• Current use of contact lenses within 30 days of Visit 1.
• Participation in any other investigational study within 30 days prior to Visit 1.
• Other protocol-defined exclusion criteria may apply.

Adverse events were collected for the duration of the study: 11 July 2008 through 03 August 2009.

Patients were queried about any symptoms they may have experienced that would suggest an AE by asking, "Since your last visit, have you had any health problems?" This reporting group includes all patients who received test article.

The subjective nature of the OSDI may not be sensitive enough to detect the effects of preservatives on the corneal surface. The measurement and quantification of OSD remains a considerable clinical challenge (Pflugfelder and Baudoin, 2011).