The Effect of Anterior Stromal Puncture Using Q-Switched Nd:YAG Laser on Corneal Wound Healing

Abstract Introduction: Recurrent corneal erosion occurs when the wounded corneal epithelium failed to adhere to the underlying stroma. Therefore, this work aimed to assess the effect of treatment of corneal injury using Q- switched Nd:YAG laser. Method: Twenty one New Zealand male rabbits weighing ۲-۲.۵ kg and ۳ months old were classified into three main groups. The control group: did not received any treatment (n=۳ rabbits). The rest of the animals (n= ۱۸ rabbits), corneal epithelium was injured by syringe needle and blade ۱۵ and divided into:(A) Normal healing group: which was divided into three subgroups (n=۳ rabbits each), and the animals were left for normal healing for۱ day, ۱ week, and ۴ weeks respectively, (B) Laser treated group: divided into three subgroups (n=۳ rabbits each) and subjected to anterior stromal puncture using Q-switched Nd: YAG laser on corneal sub-epithelium or superficial stroma, and the animals were left for ۱ day, ۱ week, and ۴ weeks respectively. After the demonstrated periods, the corneas were isolated for estimation of total protein content, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), total antioxidative capacity (TAC), total oxidative capacity (TOC) and oxidative stress index (OSI).Results: The present results of corneal total protein showed increment in the percentage change in normal healed groups after ۱ day, ۱ week and ۴ weeks by values of ۹۳%, ۶۸% and ۳۹%. In Q-switched Nd: YAG laser treated group the results showed better improvement in corneal protein than normal healed group with percentage changes of ۵۸%, ۲۹%, and ۷.۵% respectively. In SDS- PAGE, a protein band at ۱۱۰ KD appeared in the migrating epithelium for both normal healed group and Q-switched Nd:YAG laser treated group with changes in the peaks intensities at middle and low molecular weight regions. Moreover, after ۴ weeks the peak at ۱۱۰ KD disappeared in the wounded epithelium treated with Q-switched Nd:YAG. After four weeks, the OSI in laser treated corneas showed pronounced balance between antioxidative capacity and oxidative capacity.Conclusion: Anterior stromal puncture by Q-switched Nd:YAG laser is an effective, simple, safe and promising procedure to treat recurrent corneal erosion than normal healing. Keywords: Q-Switched Nd YAG lasers wound healing corneal protein