The adverse effect of perioperative brimonidine tartrate 0.2% on flap adherence and enhancement rates in laser in situ keratomileusis patients.
PURPOSE: To investigate the effect of perioperative brimonidine tartrate 0.2% on postoperative flap adherence and enhancement rates in patients undergoing laser in situ keratomileusis (LASIK). DESIGN: Noncomparative interventional case series. PARTICIPANTS: Records of 279 eyes of 144 consecutive patients who underwent LASIK between June 17, 1999, and March 1, 2000, were retrospectively reviewed. METHODS: From September 28, 1999, to November 4, 1999, 39 eyes of 20 consecutive patients had a single drop of brimonidine tartrate 0.2% instilled into their operative eye(s) before LASIK. This group was interposed in time between two nonbrimonidine groups, one before the use of brimonidine, "prior nonbrimonidine group" (107 eyes of 56 patients), and one after the use of brimonidine, "post nonbrimonidine group" (133 eyes of 68 patients). All 279 eyes in the study were examined after surgery to identify flap folds and dislocations. Enhancement rates and visual outcomes for the brimonidine and nonbrimonidine groups were also documented. MAIN OUTCOME MEASURES: Comparison of the incidence of abnormal flap appearance and enhancement rates between the brimonidine and the nonbrimonidine groups. RESULTS: In the brimonidine treated group, 6 of 39 eyes (15.4%) had an abnormal flap appearance after LASIK, although no flap folds or dislocations were noted in the nonbrimonidine groups. The difference in incidence of abnormal flap appearance between the brimonidine group and the prior and post nonbrimonidine groups was statistically significant (P = 0.0008 and P = 0.0003, respectively). When the prior and post nonbrimonidine groups were combined and compared with the brimonidine group, the difference in flap adherence was highly statistically significant (P = 0.00001). The enhancement rate was significantly higher in the brimonidine group at 36% compared with 14% in the prior nonbrimonidine group (P = 0.01) and 9% in the post nonbrimonidine group (P = 0.0004). The mean 3-month postoperative spherical equivalent was significantly greater at -0.88 diopters (D) in the brimonidine group compared with -0.24 D (P = 0.0008) and -0.15 D (P = 0.0001) in the prior nonbrimonidine and post nonbrimonidine groups, respectively. CONCLUSIONS: In this study, when perioperative topical brimonidine was used in LASIK patients, an increase in the incidence of abnormal flap adherence and an increase in enhancement rates was observed.