effect of anterior stromal puncture using Q-switched Nd:YAG laser on corneal wound healing

ABSTRACT

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 NdYAG laser. Twenty one New Zealand male rabbits weighing 2-2.5 kg and 3 months old were classified into three main groups. The control group did not received any treatment [n=3 rabbits]. The rest of the animals [n= 18 rabbits], corneal epithelium was injured by syringe needle and blade 15 and divided into[A] Normal healing group which was divided into three subgroups [n=3 rabbits each], and the animals were left for normal healing for1 day, 1 week, and 4 weeks respectively, [B] Laser treated group divided into three subgroups [n=3 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 1 day, 1 week, and 4 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]. The present results of corneal total protein showed increment in the percentage change in normal healed groups after 1 day, 1 week and 4 weeks by values of 93%, 68% and 39%. In Q-switched Nd YAG laser treated group the results showed better improvement in corneal protein than normal healed group with percentage changes of 58%, 29%, and 7.5% respectively. In SDS- PAGE, a protein band at 110 KD appeared in the migrating epithelium for both normal healed group and Q-switched NdYAG laser treated group with changes in the peaks intensities at middle and low molecular weight regions. Moreover, after 4 weeks the peak at 110 KD disappeared in the wounded epithelium treated with Q-switched NdYAG. After four weeks, the OSI in laser treated corneas showed pronounced balance between antioxidative capacity and oxidative capacity. Anterior stromal puncture by Q-switched NdYAG laser is an effective, simple, safe and promising procedure to treat recurrent corneal erosion than normal healing