Comparison of Efficacy and Safety of Two Commercial Artificial Tears Between 0.18% and 0.3% Sodium Hyaluronate for Corneal Epithelial Healing in Pterygium Excision with Conjunctival Autograft Transplantation: A Study Protocol for a Randomized Controlled Trial

PURPOSE: To compare the efficacy, safety, and rate of healing on the corneal epithelial defect after pterygium surgery through the application of either 0.18% or 0.3% sodium hyaluronate (SH). METHODS: A randomized, double-blind clinical trial was performed on patients who had pterygium surgery. Eighty-six patients were randomized to 2 groups that would receive either 0.18% SH or 0.3% SH. Measurements of area of the corneal epithelial defect using ImageJ freeware were performed. All corneal epithelial defects were measured immediately after the operation (Day 0) and for the next 3 days. RESULTS: The mean and SD of the area of corneal epithelial defect measured on postoperative Day 0, 1, and 2 were 9.13 ± 3.09 mm(2), 5.61 ± 3.26 mm(2), and 3.39 ± 2.70 mm(2) for 0.18% SH group, and 8.96 ± 3.17 mm(2), 4.03 ± 1.99 mm(2), and 1.55 ± 1.23 mm(2) for 0.3% SH group. There was no statistically significant difference of the initial area of the corneal epithelial defect on Day 0 between 0.18% and 0.3% SH group (p = 0.802). The area of the defects in the 0.3% SH group was significantly smaller than that of the 0.18% SH group on both Day 1 and Day 2 (p = 0.007, p < 0.001), respectively. Similarly, the 0.3% SH group exhibited a statistically significant higher (p < 0.001) rate of healing of the corneal epithelial defect over days 0 and 1 (4.94 ± 2.16 mm²/day) when compared to that of the 0.18% SH group (3.53 ± 1.66 mm²/day). CONCLUSION: With two commercial artificial tears, the corneal epithelial wound healing after pterygium surgery was faster in the 0.3% SH group than that of the 0.18% SH group. Superiority of 0.3% SH may be supported by the presence of epsilon-aminocaproic acid in this drug preparation. No significant adverse effects were exhibited during the short-term follow-up.