INTRAOCULAR ADRENALINE MAINTAINS MYDRIASIS DURING CATARACT-SURGERY

Cataract surgery is performed more easily if mydriasis can be maintain ed until the intraocular lens has been inserted. Intraocular irrigatio n with adrenaline is thought to be of benefit in this respect, and is used by some surgeons but not others. This prospective double blind co ntrolled trial assessed the efficacy and safety of using perioperative adrenaline during extracapsular cataract surgery, as an adjunct to pr eoperative topical mydriatics. Seventy patients were randomised to rec eive intraocular irrigation fluid with or without 1:1000000 adrenaline . The adrenaline entering the eye through the anterior capsulotomy nee dle helped to resist the miosis induced by expression of the nucleus ( 7.1 versus 6.5 mm). The mydriasis maintained during irrigation aspirat ion was significantly greater in the group receiving adrenaline (6.6 v ersus 6.0 mm, p<0.02). Their pupil diameters were also significantly l arger at 20 minutes (p<0.001) and 30 minutes (p<0.01) into surgery. Pu pillary constriction to a diameter of less than 5 mm occurred more fre quently in the group not receiving adrenaline. Pulse rate and blood pr essure in the 27 patients who had local anaesthesia showed no signific ant difference between the treatment groups (p>0.05), and there was no significant variation from baseline (p>0.05). Intraocular irrigation with adrenaline 1:1000000 is a safe and effective means of maintaining mydriasis during cataract surgery.