Corticosteroid suppression of trauma-induced hyaluronan in rabbit cornea and aqueous.
BACKGROUND
Corneal and aqueous hyaluronan have recently been shown to react in response to several different types of trauma, including cataract surgery. In order to find ways to influence the reaction, we have evaluated the effect of topical dexamethasone (Isopto-Maxidex, Alcon Universal Ltd, Fort Worth, Tex) or indomethacin (Confortid, Dumex Ltd, Copenhagen, Denmark) on the postoperative hyaluronan concentration in rabbit cornea and aqueous after extracapsular lens extraction.


METHODS
The drugs were administered as topical eye drops three times daily. The hyaluronan concentration in rabbit cornea and aqueous after extracapsular lens extraction was measured with a radioligand assay.


RESULTS
Dexamethasone treatment (1 mg/mL) significantly suppressed the increase in corneal hyaluronan seen after extracapsular lens extraction, 2 (p < or = 0.0022) and 3 weeks (p < or = 0.0002) after surgery, while indomethacin did not induce any significant difference at 2 weeks. When the dexamethasone concentration was lowered to 0.1 and 0.2 mg/mL, there was still a significant decrease (p < or = 0.009) in hyaluronan concentration, but at lower concentrations of dexamethasone (0.01 and 0.02 mg/mL), no significant decrease was seen. The increase in aqueous hyaluronan concentration seen 2 days after surgery in untreated eyes was significantly lowered by both dexamethasone (p < or = 0.0076) and indomethacin (p < 0.036).


CONCLUSIONS
Dexamethasone lowers reactive corneal and aqueous hyaluronan concentration in vivo after extracapsular lens extraction.
D000287:Administration, Topical; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage; D001082:Aqueous Humor / Q000187:drug effects / Q000378:metabolism*; D002387:Cataract Extraction; D003315:Cornea / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D003907:Dexamethasone / Q000008:administration & dosage*; D005938:Glucocorticoids; D006651:Histocytochemistry; D006820:Hyaluronic Acid / Q000378:metabolism*; D007213:Indomethacin / Q000008:administration & dosage; D009883:Ophthalmic Solutions; D011817:Rabbits; D014945:Wound Healing / Q000502:physiology
D000893:Anti-Inflammatory Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D005938:Glucocorticoids; D009883:Ophthalmic Solutions; D003907:Dexamethasone; D006820:Hyaluronic Acid; D007213:Indomethacin