EFFECT OF DICLOFENAC ON PROSTAGLANDIN LIBERATION IN THE RABBIT AFTER PHOTOREFRACTIVE KERATECTOMY

BACKGROUND: An analyses of the concentration of arachidonic acid metab olites and the infiltration of leukocytes in the aqueous humour of rab bits after excimer laser keratectomy was performed. The ability of top ical diclofenac to block prostaglandin E-2 liberation into the aqueous humour was also investigated. METHODS: Photorefractive keratectomy wa s performed on both eyes of 60 New Zealand rabbits. Prostaglandin E-2, 6-keto prostaglandin F-1 alpha and thromboxane B-2 were detected by r adioimmunoassay and leukocytes were counted in the aqueous humour for 120 hours postoperatively. Topical diclofenac was instilled (1 drop/4h ) in six animals and prostaglandin E-2 was analyzed in the aqueous hum our 16 hours postoperatively. RESULTS: The prostaglandin E-2 concentra tion in the aqueous humour increased from 13 in control animals, to 25 1 pg/100 mu l at 16 hours after treatment (p<0.05). A statistically si gnificant elevation in the aqueous concentration of 6-keto prostagland in F-1 alpha could not be demonstrated. Thromboxane B-2 and leukocytes could not be detected at any time point. Topical diclofenac (1 drop/4 h) reduced the levels of prostaglandin E-2 in the aqueous humour below 10 pg/100 mu l, 16 hours postoperatively. CONCLUSION: Topical diclofe nac (1 drop/4h) inhibited prostaglandin E-2 release into the aqueous h umour.