Exploring the Effects of a Preservative-free Ophthalmic Solution Containing Hyaluronic Acid 0.4% and Taurine 0.5% on the Ocular Surface of Glaucoma Patients Under Multiple Long-term Topical Hypotensive Therapy

At the screening visit all patients underwent comprehensive ophthalmological examination including best corrected visual acuity assessment, slit lamp evaluation, IOP measurement using Goldmann applanation tonometry, and indirect dilated ophthalmoscopy with a 90 diopters lens. Visual field testing using Humphrey 24-2 SITA-Standard program (Carl Zeiss Meditec, Inc., Dublin, CA 24-2 program) was performed only for those patients with the last exam older than 3 months.

Baseline visit was splitted in two visits scheduled 1 week apart 2 days, to evaluate ocular surface alterations by means of several tests.

To minimize the influence of each test on the subsequent test, we performed first the least invasive and then the most invasive test. During the first baseline visit patients were asked to fill two questionnaires, the Ocular Surface Disease Index (OSDI) and the Glaucoma Symptom Scale (GSS) and then underwent the Break Up Time test (BUT), corneal and conjunctival staining evaluation using Oxford Staining Scheme, and Schirmer I test after 15 minutes of rest. During the second baseline visit, patients underwent conjunctival Confocal Laser Microscopy with the Rostock Module of Cornea of the Heidelberg Retina Tomograph (HRT3, Heidelberg Engineering Gmbh, Heidelberg, Germany).

At the end of the second baseline visit patients were randomized in two groups with a 1:1 ratio according to a computer-generated randomization list.

Group 1 (HA0.4%+TAU0.5%) was asked to self-administer 1 drop four times/day of a preservative-free ophthalmic solution containing 750KDa HA 0.4% and TAU 0.5% in both eyes, while Group 2 (HA0.2%) was asked to self-administer 1 drop four times/day of a preservative-free ophthalmic solution containing only 750KDa HA 0.2%, in addition to the ongoing hypotensive therapy.