Changes in the morphological and functional patterns of the ocular surface in patients treated with prostaglandin analogues after the use of TSP 0.5%® Preservative-Free Eyedrops: A prospective, multicenter study

Aim: To investigate and compare the effects of topical benzalkonium chloride-preserved prostaglandins (PGAs) on the ocular surface in patients with primary open-angle glaucoma before and after 3 months of treatment with additional 0.5% preservative-free tamarind seed polysaccharide single-dose eyedrops (TSP®, Oftagen, Pisa, Italy). Methods: This was a prospective, longitudinal, multicenter study. From 5 different Italian glaucoma centers, 10 glaucomatous patients were recruited in each center. All the patients were treated with a PGA with preservative for at least 1 year. Preservative-free artificial tears 3 times per day were prescribed. The participants were subjected to clinical and instrumental evaluation at baseline, after 1 month and after 3 months of treatment. All patients were examined with a digital corneal confocal laser scanning microscope (HRT II Rostock Cornea Module). Results: After 3 months of TSP 0.5% treatment, an improvement of some ocular signs and symptoms was found. The percentage of conjunctival hyperemia decreased from 67 to 13%. Schirmer's test and breakup time significantly changed from the baseline after 3 months. Confocal microscopy showed a significant increase in conjunctival goblet cells. Conclusion: Artificial substitutes, in particular TSP 0.5%, might protect the ocular surface hence giving higher compliance, adherence and quality of life to the patients.