Experimental Study On Homoharringtonine Inhibiting Haze After Laser Subepithelial Keratomileusis In Rabbits

Objective To investigate the therapeutic effect of Homoharrin- gtonine (HHT) on corneal haze formation after laser subepithelial keratomileusis (LASEK) in rabbits.Methods This study was a prospective, randomized animal experiment. Forty-eight New Zealand white rabbits were underwent -10.0 diopters laser subepithelial keratomileusis(LASEK) . All eyes were randomLy divided into 4 groups by self-control , group A:1mg/mL HHT during operation treating group ,group B: 0.1mg/mL HHT after operation treating group,group C:0.1% fluorometholone (FML) after operation treating group,group D: balanced salt solution (BBS) after operation treating group as control group. And there were twenty-four eyes in each group . Partâ… :After the operation , corneal epithelium healing time , ocular objective sign and corneal haze grades were periodicly observed and evaluated by slit lamp microscope . Partâ…¡: Histopathologic examinations were made with light microscope when1,2week,1,2,3,and 6 month after the operation ,and with transmission electron microscope when 1,3,and 6 month after the operation .Results1. The time of reepithelialization were insignificant differences among all groups (P>0 05).2. Corneal ha??rades after surgery were significant differences among all groups (P<0.05),and were significant differences at different observation time point postoperatively (P<0.05), and the role of time factor do not differ with the difference of group(P>0.05). 3. Pairwise comparisons at different observation time point of outcomes showed that at 1 month and 2 months after the operation ,the Corneal haze grades was significantly less in group A, group B and group C, comparing with group D (P< 0.05), but there were no significant difference among the other three groups(P>0.05). For the rest observation time point , there were no significant difference among the four groups(P>0.05) .4. Light microscopy and transmission electron microscopy examination revealed that the structure of the epithelial layer in each group was intact. And the anterior stromal proliferative reactions among group A,group B and group D were apparently weaker than that in group D ,which suggested that both HHT and FML have inhibitive effect on corneal haze formation after laser subepithelial keratomileusis in rabbits. The more excessive epithelial hyperplasia and subepithelia collagen proliferation was found in group D,and that were inhibited in the other three groups , especially in the group A .Conclusion Homoharringtonine could inhibit rabbit corneal haze formation after LASEK by inhibiting the proliferation of corneal stroma fibroblastic and the synthesis of collagen fib??,which were similar to FML . The effect of high concentration, short-term administration method is similar to that of low concentration, long-time administration method. Homoharringtonine is a promising medicine to inhibit corneal haze after laser subepithelial keratomileusis for clinical in future,and this experimentation maybe offer an effective experimental evidence .