Comparison of the goblet cells' density and the quality of tears in treatment with sodium hyaluronate 0.1% benzalkonium chloride preservative-free eye drops for patients with glaucoma and dry-eye syndrome: A double-blind randomized clinical trial

This study aims to compare the efficacy of benzalkonium chloride (BAK) on different goblet cells densities and to enhance the quality of tears in patients with glaucoma and dry-eye syndrome treated with preservative-free and preserved sodium hyaluronate (SH) 0.1% eye drops. In this double-blind, randomized clinical trial, we randomly assigned patients with glaucoma and dry-eye syndrome into two groups: group I, treated with SH 0.1% eye drops comprising BAK preservative (a positive comparator group); group II, treated with preservative-free SH 0.1% eye drops. We followed patients for 3 months after enrollment and assessed the quality of tears by examining symptoms and signs, including the Schirmer's test, tear film break-up time (TFBUT), Ocular Protection Index (OPI), and conjunctival impression cytology pre- and post-treatment. Any ocular discomfort was assessed by using the Ora Calibra Ocular. We enrolled 40 eyes from 20 patients with glaucoma and dry-eye syndrome. Each group comprised 20 eyes of 10 patients. We observed increased values of the mean TFBUT, OPI, and Schirmer's test pre- and post-treatment, with no significant difference between both groups. While the conjunctival impression cytology revealed similar results of goblet cells in both groups, we observed lower scale of the Ora Calibra Ocular. Both groups elicit a comparable improvement in the quality of tears as demonstrated by augmented results of the Schirmer's test, TFBUT, OPI, and Ora Calibra Ocular Score of patients with glaucoma and dry-eye syndrome.