Abstract
Purpose: :
This study assesses the efficacy of the pre-operative topical use of hypromellose gel 0.3% (GenTeal Gel, Novartis Ophthalmics, Basel, Switzerland) in enhancing the speed of re-epithelialization after LASIK within the first post-op week, as compared to control (no pre-op lubricant).
Methods: :
This study is a parallel two-group, assessor-masked study where patients scheduled for LASIK are randomized to either pre-op treatment with hypromellose gel 0.3% qid for five days prior to surgery, or no lubricant, with an n of 40 patients in each group, which is expected to provide 80% power to determine differences at alpha=0.05. The post-op LASIK patients will be evaluated on post-op day 1, and weeks one and four. They will be graded as to the number of clock hours of epithelial defect in the gutter of the flap, as determined by fluorescein staining. The number of clock hours of epithelial healing per hour in the immediate post-operative period will be calculated. In addition, the patients will rate the comfort level of their eyes at each gate, using the visual analog scale. Analysis of covariance will be used to analyze healing of the gutter.
Results: :
At this time, group one, no hypromellose gel pre-op, has an n of 21 at the day one post-op gate. Group two, with hypromellose gel pre-op, has an n of 26 at day one. The analysis of the average number of clock hours of healing of the gutter per hour post-op suggests faster healing in the pre-treated group (0.22 clock hours of gutter epithelial regeneration per hour vs. 0.19 in the untreated group.) Analysis of the subjective questions shows a trend to less "average" pain on day 1 post-op in group two (average "average" pain score 3.24 vs. 2.77 in the treated group.} Also, there was a trend to less "maximum" pain on day 1 post-op in group two. (Average "maximum" pain score 5.24 vs. 5.08 in the treated group.) As well, a majority of patients across both groups felt that the post-op use of hypromellose solution was associated with improved comfort. (range 67% to 79%) The statistical significance of these differences remains to be established.
Conclusions: :
Analysis of data to date suggests that the rate of re-epithelialization of the gutter around a LASIK flap during post-op day one may be increased by 5 days of pre-treatment with hypromellose 0.3% gel. Perhaps related, patients report less average and maximum post-op pain when pre-treated. We plan on completing patient enrollment, with statistical analysis as described above, with discussion by April 2009, for presentation at the 2009 ARVO meeting.
Clinical Trial: :
www.clinicaltrials.gov NCT00598689
Keywords: cornea: epithelium • refractive surgery: LASIK • wound healing