Effect of diclofenac on prostaglandin liberation in the rabbit after photorefractive keratectomy.

BACKGROUND An analyses of the concentration of arachidonic acid metabolites and the infiltration of leukocytes in the aqueous humour of rabbits after excimer laser keratectomy was performed. The ability of topical diclofenac to block prostaglandin E2 liberation into the aqueous humour was also investigated. METHODS Photorefractive keratectomy was performed on both eyes of 60 New Zealand rabbits. Prostaglandin E2, 6-keto prostaglandin F1 alpha and thromboxane B2 were detected by radioimmunoassay and leukocytes were counted in the aqueous humour for 120 hours postoperatively. Topical diclofenac was instilled (1 drop/4h) in six animals and prostaglandin E2 was analyzed in the aqueous humour 16 hours postoperatively. RESULTS The prostaglandin E2 concentration in the aqueous humour increased from 13 in control animals, to 251 pg/100 microliters at 16 hours after treatment (p < 0.05). A statistically significant elevation in the aqueous concentration of 6-keto prostaglandin F1 alpha could not be demonstrated. Thromboxane B2 and leukocytes could not be detected at any time point. Topical diclofenac (1 drop/4h) reduced the levels of prostaglandin E2 in the aqueous humour below 10 pg/100 microliters, 16 hours postoperatively. CONCLUSION Topical diclofenac (1 drop/4h) inhibited prostaglandin E2 release into the aqueous humour.