Early wound healing of laser in situ keratomileusis–like flaps after treatment with human corneal stromal stem cells

PURPOSE: To use a well-established organ culture model to investigate the effects of corneal stromal stem cells on the optical and biomechanical properties of corneal wounds after laser in situ keratomileusis (LASIK)–like flap creation. SETTING: School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom. DESIGN: Experimental study. METHODS: The LASIK-like flaps were produced in sheep corneas. The flap beds were treated with corneal stromal stem cells and were then replaced and allowed to heal for different periods of up to 3 weeks in organ culture. The optical transmission of the cornea, the force required to detach the flap, and the presence of myofibroblasts near the flap bed were measured. RESULTS: Corneal stromal stem cell–treated flap beds were statistically significantly more transparent after 3 weeks in culture than the untreated controls. At 3 weeks, the mean force necessary to detach the flap was more than twice the force required for the respective control samples. Concurrently, there were 44% activated cells immediately below the flap margin of the controls compared with 29% in the same region of the corneal stromal stem cell–treated flaps. CONCLUSIONS: In this system, the presence of corneal stromal stem cells at the wound margin significantly increased the adherence of LASIK-like flaps while maintaining corneal transparency. It is postulated that this is achieved by the deposition of extracellular connective tissue similar to that found in the normal cornea and by the paucity of activated keratocytes (myofibroblasts), which are known to scatter a significant amount of the incident light. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.