To investigate the impact of recombinant human epidermal growth factor (rh-EGF) on the epithelial recovery and the tear film stability after trans-epithelial corneal collagen crosslinking in patients with progressive keratoconus.

A randomized controlled clinical trail was designed.Consecutive 66 patients (37 males and 29 females) with an average age of (21.27±3.80) years old diagnosed with primary progressive keratoconus and hospitalized in Xiamen Eye Center Affiliated to Xiamen University from October, 2016 to January, 2017 were enrolled and treated with unilateral enhanced transepithelial corneal crosslinking surgery by iontophoresis, and the patients were randomly divided into control group and experimental group according to random number table method, with 33 patients 33 eyes in each group.The eyes in the control group were treated with carboxy-methylcellulose sodium lubricant eye drops and the eyes in the experimental group were treated with rh-EGF eye drops.The ocular surface disease index (OSDI) questionare, slit lamp examination, Schirmer Ⅰ test, corneal fluorescein sodium staining scoring, non-contact tonometry, uncorrected visual acuity, best corrected visual acuity, bulbar conjunctival congestion scoring, lacrimal sevretion test, non-invasive break-up time of tear film (NIBUT), as well as tear meniscus height analysis were performed before surgery, and on day 1, day 3, day 5, day 7, day 14 and day 28 after surgery.This study followed the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Xiamen Eye Center Affiliated to Xiamen University (No.2016-ME-003).

On day 7 after surgery, the OSDI values were increased in both groups than the preoperative value, while the value in the experimental group was significantly lower than that in the control group (P<0.05). There were statistically significant differences in the overall corneal epithelial staining score values between the two groups at different time points (F_group=16.701, P<0.01; F_time=454.418, P<0.01). The corneal epithelial staining score in the experimental group on day 3 and day 5 after surgery were significantly lower than those in the control group (1.79±0.65 vs. 2.70±0.68; 0.91±0.46 vs. 1.55±0.51) (both at P<0.01). The conjunctival congestion score in the experimental group was significantly lower than that of the control group on day 3 and day 5 after surgery (both at P<0.05). There were statistically significant differences in the overall NIBUT values between the two groups at different time points (F_group=13.084, P<0.01; F_time=34.383, P<0.01). The NIBUT values were significantly decreased rapidly on day 7, day 14 and day 28 after surgery in both groups (all at P<0.01), but gradually recovered.The NIBUT of the experimental group on day 7 and day 14 after surgery were significantly higher than those of the control group ([8.18±2.26]seconds vs. [5.93±2.33]seconds; [9.49±1.95]seconds vs. [7.52±2.27]seconds) (both at P<0.01). No statistical differences were found in the tonometry value, visual acuity, value of Schirmer I test as well as tear meniscus height at any time point before or after surgery between the two groups (all at P>0.05).

Recombinant human epidermal growth factor has positive effects in the patients received enhanced transepithelial corneal crosslinking surgery, presenting with promotion of epithelial healing, relief of post-operative discomfort, and the recovery of tear film stability.

Recombinant human epidermal growth factor; Keratoconus; Corneal collagen crosslinking; Corneal epithelial defect; Tear film