Abstract
Abstract: :
Purpose: To investigate the corneal healing effect of sodium hyaluronate (Na–Ha) in patients undergone photorefractive keratectomy (PRK). Methods: This was a randomized, single–masked, parallel–group study. Forty patients (age 29.4 ± 4.1 years, m± SD) with moderate myopia (–1.25 to –3.75 diopters) undergoing PRK were randomized into 2 treatment groups. Group 1 (20 patients) received non preserved 0.2% high molecular weight Na–Ha (HYALISTIL SIFI) t.i.d. starting the day of surgery for 90 days. Group 2 (20 patients) did not receive Na–Ha (control group). Corneal wound healing was assessed by slit lamp examination and fluorescein staining 3, 7, 30, 60 and 90 days after surgery scoring the degree of erosion on a 0 to 3 categorical scale. Corneal morphology was evaluated at the same times by confocal microscopy. Other parameters investigated were: haze, symptoms and tear film break up time (BUT). Results: A lower incidence of micro–erosions in the Na–Ha–treated group was observed after 7 and 30 days of treatment (p=0.022 and p=0.031, respectively, Wilcoxon test). A lower occurrence of burning was detected as well (p=0.001 and p=0.003, day 7 and 30, respectively, Wilcoxon test). Moreover, tear film BUT increased as from 30 days of administration of Na–Ha (p= 0.005 after 30 days, p=0.001 after 60 and 90 days, paired t test). Finally, at the end of the study (90 days after PRK) all treated patients (compared to 60% of the control group) were free of dry eye symptoms (McMonnies) (p=0.016, Wilcoxon test). Differences between groups for all other variables, including haze and epithelium morphology, were not statistically significant. Conclusions: Use of non preserved 0.2% hyaluronic acid (HYALISTIL SIFI) after PRK resulted in a more rapid recovery of the ocular surface, a reduction of clinical signs of micro–erosions and an improvement of tear film BUT.
Keywords: cornea: clinical science • cornea: epithelium • refractive surgery