Prospective, randomized, single masked, parallel study 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

Introduction: To compare the effects of a preservative-free (PF) ophthalmic solution containing hyaluronic acid (HA) 0.4% and taurine (TAU) 0.5% with those of a PF ophthalmic solution containing HA 0.2% on ocular surface signs, symptoms, and morphological parameters in glaucoma patients under multiple long-term topical hypotensive therapy. Methods: Eligible patients underwent evaluation of ocular surface parameters by ocular surface disease index (OSDI) and glaucoma symptom scale (GSS) questionnaires, breakup time test (BUT), Schirmer I test, corneal and conjunctival staining (Oxford scale), and conjunctival in vivo confocal microscopy (Heidelberg Retina Tomograph 3, Heidelberg Engineering GmbH, Heidelberg, Germany). After the baseline visit, patients were randomized to use a PF ophthalmic solution containing HA 0.4% and TAU 0.5%, QID, in both eyes (group 1) or to use a PF ophthalmic solution containing HA 0.2%, QID (group 2) in addition to the ongoing preserved hypotensive treatment. Follow-up visits were scheduled at 30 and 90 days. Results: Thirty-nine eyes of 39 glaucoma patients were included in the study. At baseline, results of study tests of both groups were similar. After 90 days in group 1 the BUT (p = 0.01), the Oxford score (p = 0.03), the conjunctival goblet cells (CGC) density (p = 0.0005) ,and the two questionnaires score significantly improved (OSDI, p = 0.003; GSS, p = 0.003) compared to baseline values, while in group 2 all these parameters did not differ from baseline (BUT, p = 0.39; Oxford score, p = 0.54; CGC density, p = 0.33, OSDI p = 0.65, GSS, p = 0.25). The BUT and the CGC density were statistically different between groups both at 30 and 90 days (p = 0.04 and p = 0.04, respectively). The Schirmer I test did not statistically change after 90 days in both groups. Conclusions: The PF ophthalmic solution with HA 0.4% and TAU 0.5% seems to improve CGC density and reduce signs and symptoms of dry eye in glaucoma patients under long-term multiple preserved hypotensive therapy.