Abstract
Abstract: :
Purpose: Unilateral corneal stem cell deficiency may be managed by autologous stem cell transplantation. Iatrogenic stem cell deficiency in the donor eye may result from harvesting too much tissue. We describe a technique to minimize this surgical complication by harvesting multiple small 1.0mm corneal stem cell buttons and securing them to the recipient bed with fibrin glue (Tisseel). We modified our earlier protocol (1446/B257 ARVO 2004) to maximize the adhesiveness of the donor graft to the recipient cornea by creating a lamellar dissection in the recipient bed to promote graft adherence. Methods: Following anesthesia , the corneal epithelium of 8 left rabbit eyes was removed by mechanically scraping with a #66 blade. A 180–degree superior peritomy was performed. Then a #66 blade was used to make a partial thickness 2 mm wide scleral tunnel incision into clear cornea. A 1.0 mm skin punch was used to create a partial thickness lamellar bed at the 10:00, 12:00, and 2:00 positions. Three 1.0 mm donor buttons were obtained from the corresponding positions on the right eyes using a similar techinque. Tisseel (Baxter Healthcare Corp) adhesive was used to affix the donor buttons. A drop of the thrombin component was placed on the donor, and a drop of the fibrinogen was used on the recipient and the two surfaces were brought into contact. The glue was allowed to settle for 5 minutes prior to the placement of a bandage contact lens. Post–operative evaluation included assessment of the location and number of remaining grafts and photographic documentation of the epithelial defect. Results: Twenty–four grafts were affixed to 8 recipient de–epithelialized corneas with Tisseel. At post–op day 1, all 24 grafts remained. At post–op day 3, 19 grafts remained affixed. A total of 18 grafts remained at day 5. In five rabbits, all 3 buttons remained for the duration of the experiment. In each of the remaining three, only 1 graft was affixed on day 5. In two of these rabbits, the 12:00 position grafts remained. In one of these, the 10:00 position graft remained affixed. The pattern of epithelialization seemed to be a wave front from the limbus centrally. Finally, there appeared to minimal epithelial migration from the donor grafts. Conclusions: Compared with the results of our previous study, lamellar dissection of the recipient bed greatly promotes graft adherence. Furthermore, Tisseel appears to be a feasible method for affixing 1.0mm limbal grafts to a lamellar recipient bed. Further study is warranted to evaluate the mechanism of corneal epithelialization in the setting of Tisseel.
Keywords: cornea: epithelium • conjunctiva • anterior segment