TOPICAL DICLOFENAC TREATMENT PRIOR TO EXCIMER-LASER PHOTOREFRACTIVE KERATECTOMY IN RABBITS

PURPOSE: This study sought to determine whether pre- and posttreatment with topical diclofenac sodium 0.1% eye drops suppresses corneal infl ammation after 193-nanometer excimer laser corneal ablation more effec tively than does posttreatment alone. METHODS: Eight rabbits were divi ded into four groups. Animals in group I were treated with topical dic lofenac every half hour for 2 hours prior to photorefractive keratecto my; treatment was continued every hour for 3 hours after the ablation. Group II animals, used as controls, were treated with the diclofenac vehicle according to the same schedule. The third group (III) received diclofenac topically only after the excimer laser ablation. The fourt h group (IV) consisted of normal corneas from these same animals. At 3 hours after ablation, prostaglandin E2 (PGE2) levels were measured in the corneas and leukocytes were quantified. RESULTS: Treatment with t opical diclofenac significantly reduced levels of PGE2 compared to tre atment with the vehicle (p = .024). Presurgical treatment with topical diclofenac did not result in greater suppression of PGE2 than did pos ttreatment alone (5.72 +/- 0.91 pg/mL versus 5.79 +/- 1.29 pg/mL). Sim ilarly, there was a significant inhibition of leukocyte invasion in th e diclofenac treated corneas (I vs II: p = .019, III vs II: p = .024), but no statistically significant difference between pretreatment and posttreatment alone groups (I vs III: p = .72). CONCLUSIONS: Topical a dministration of diclofenac reduces the release of PGE2 and the migrat ion of polymorphonuclear leukocytes in the rabbit cornea 3 hours after 193-nanometer excimer laser ablation. However, pretreatment of the co rnea, starting 2 hours prior to laser surgery, does not seem to offer advantages over postablation treatment in this animal model.