Apraclonidine and LASIK

Dear Editor: LASIK is a popular and relatively safe surgical procedure for the correction of myopia, hyperopia, and astigmatism. The proper adhesion between flap and stromal bed is mandatory to restore the corneal integrity and set the background for an adequate refractive outcome properly. Many refractive surgeons started using topical vasoconstrictors to reduce postoperative hyperemia and subconjunctival hemorrhages. However, any positive effect of topical vasoconstrictors on subconjunctival hemorrhage would be rightfully overshadowed by any flap adherence problems, such as flap slippage. Although we greatly enjoyed a study conducted by Walter and Gilbert, we were alarmed by its conclusions that the use of a vasoconstrictor, brimonidine, might increase the incidence of such complications. Moreover, we see several flaws in the report. Apart from its not being a prospective, randomized, double-blind clinical study, the sample size seemed inadequate. A total number of 279 eyes was divided into 3 groups: the first and the last group represented the patients who underwent a standard LASIK procedure (2 control groups), whereas only the 39 eyes in between (both eyes of all patients) actually received brimonidine. Based on our understanding of flap complications, whose incidence is reported to be 2%, this number of eyes represents an inadequate sample size. Moreover, the 3 groups of patients are not statistically comparable in terms of preoperative spherical equivalent (SE), gender, and age. To overcome these problems, we conducted a prospective, randomized, double-masked study to detect the potential influence of the topical use of apraclonidine just before the LASIK procedure on postoperative flap adherence and to