Pathogenesis and management of laser in situ keratomileusis flap buttonhole

Abstract

PurposeTo describe the clinical features and outcomes in patients who had a flap buttonhole during laser in situ keratomileusis (LASIK) and propose an etiopathogenic mechanism for this complication. SettingUniversity Eye Center, Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China. MethodsRetrospective review of case records of 6 patients (6 eyes) who had a flap buttonhole during LASIK. ResultsThe mean patient age was 38.2 years ± 4.1 (SD) and the mean preoperative spherical equivalent (SE) refraction, −8.13 ± 4.04 diopters (D). Mean keratometry was 44.20 ± 1.30 D. Retreatment was performed after a mean interval of 9.2 ± 3.2 months. Final postoperative SE refraction was −0.44 ± 0.58 D after a mean follow-up of 59.0 ± 5.3 weeks. No patient experienced loss of best spectacle-corrected visual acuity. ConclusionsRetreatment of eyes that have a flap buttonhole during LASIK is associated with good visual outcomes. Flap buttonholes can produce alterations in refraction, so retreatment is best performed after the refractive error has stabilized. Microkeratome malfunction may be responsible for the occurrence of a flap buttonhole during LASIK in eyes that do not have significant corneal steepening.