Purpose: To examine the etiology and management of buttonholes created during laser in situ keratomileusis (LASIK).
Patients and methods: Retrospective review of case records of 1010 eyes of 514 patients who underwent LASIK. Four eyes of 4 patients developed a flap buttonhole, and subsequent laser ablation was not performed. Retreatment was done after a mean interval of 6 months.
Results: The etiology of a buttonhole was considered to be misuse of microkeratome in 1 patient and desiccation of the cornea in 2 patients, and could not be determined in 1 patient. Uncorrected visual acuity in those 4 patients was 1.2, 1.2, 0.9, and 1.5 respectively, after retreatment. The mean preoperative spherical equivalent was -5.47 diopters(D), and the mean spherical equivalent before retreatment was -5.19 D. The mean preoperative corneal refractive power of 43.53 D flattened to 42.88 D before retreatment. The mean preoperative corneal astigmatism of 1.63 D increased to 2.06 D before retreatment.
Conclusion: Misuse of microkeratome and desiccation of the cornea may cause a buttonhole. If a buttonhole is created, retreatment by LASIK scheduled several months later may achieve good uncorrected visual acuity.