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Purpose To investigate the effect of acute and chronic exposure to IR on rabbit corneal and lens metalloproteinase‐2 (MMP‐2), MMP‐9 and glycosaminoglycans (GAGs) and the influence of COX inhibition. Methods Fourteen (14) New Zealand rabbits were used totally. Chronic exposure to IR included 4 month irradiation of 3 rabbits, whereas 3 animals were the control group. Regarding acute exposure, 8 rabbits were used, diclofenac sodium eye drops 0.1% were instilled in their right eyes and 4 of them were irradiated for 12 hours. By comparing the left irradiated with the left non‐irradiated eyes, the effect of IR exposure was investigated. COX inhibition role with and without IR exposure was determined, by comparing the left with the right eyes of the irradiated and the non‐irradiated rabbits separately.The cornea and lens were extracted, followed by gelatin zymography to determine MMP‐2 and MMP‐9 activity, GAGs isolation, measurement of uronic acids and electrophoresis on cellulose acetate membranes for GAGs analysis. Results Chronic IR exposure induced the activity of corneal and lens pro‐MMP‐2 activity but did not affect GAGs. Acute exposure increased corneal and lens pro‐MMP‐2 activity and lens heparan sulfate amount, whereas the use of diclofenac sodium was unable to influence these effects. Conclusion Corneal and lens acute and chronic IR exposure induced the activity of pro‐MMP‐2. Acute exposure, also, increased lens heparan sulfate amount. [ABSTRACT FROM AUTHOR]