Abstract
INTRODUCTION: This study aimed to compare the effect of two preservative-free (PF) artificial tears, one containing carboxymethylcellulose (CMC) (control group) vs another containing hyaluronic acid and hydroxypropyl guar (HA + HP-guar) (study group), on the healing of the corneal epithelium and the ocular discomfort after bilateral photorefractive keratectomy (PRK) surgery. METHODS: A total of 68 patients that were scheduled to have PRK to correct myopia were randomized into two groups: 34 patients (68 eyes) in the study group and 34 patients (68 eyes) in the control group. Ocular examinations were performed on postoperative days 1, 4, 7, 30, and 90, evaluating the diameter of the de-epithelized cornea, the fluorescein staining using the Oxford scale, the tear film osmolarity and stability (tear breakup time), and the pain using visual analog scale (VAS). RESULTS: On postoperative day 4, 97% of the study eyes vs 84.4% of the control eyes were completely re-epithelized (p = 0.01). Less ocular pain was observed on postoperative day 3 in the study group (5.0 (3.0-6.0) vs 6.0 (3.5-7.0), p = 0.03). No differences were observed beyond postoperative day 7 in the healing of the corneal epithelium, non-invasive Keratograph breakup time (NIKBUT), and the self-perceived ocular discomfort between the two groups. CONCLUSION: The current study shows faster healing of the corneal epithelium and less ocular pain and discomfort in the first days after PRK with the use of topical lubricants containing HA + HP-guar compared to conventional CMC artificial tears, probably due to the different trophic effect of the aforementioned tears on the corneal epithelial cells. TRIAL REGISTRATION: EudraCT No. 2020-003488-25.