Switching From Preserved to Preserved-free Treatments for Glaucoma.

The study protocol comprises 5 visits: baseline, month 3, month 6, month 9, month 12. At baseline a clinical evaluator will perform a complete ophthalmologic evaluation to confirm diagnosis. The following examinations will be done in the following sequence: anterior segment examination, Shirmer test, Break-up time test. Thereafter, a confocal evaluator will perform confocal microscopy of the central and the peripheral cornea. Finally, contact measurements will be done in the following order: IOP (which will be measured at 3 pm), pachimetry (only at baseline visit) and gonioscony (only at baseline visit). A 15 minutes interval will elapse between two consecutive tests.