Pathogenesis and management of laser in situ keratomileusis flap buttonhole

Purpose: To 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. Setting: University Eye Center, Department of Ophthalmology and Visual Scie nces, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong K ong, China. Methods: Retrospective review of case records of 6 patients (6 eyes) who ha d a flap buttonhole during LASIK. Results: The mean patient age was 38.2 years +/- 4.1 (SD) and the mean preo perative spherical equivalent (SE) refraction, -8.13 +/- 4.04 diopters (D). Mean keratometry was 44.20 +/- 1.30 D. Retreatment was performed after a m ean 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 ex perienced loss of best spectacle-corrected visual acuity. Conclusions: Retreatment of eyes that have a flap buttonhole during LASIK i s associated with good visual outcomes. Flap buttonholes can produce altera tions 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 signi ficant corneal steepening. J Cataract Refract Surg 2000; 26:358-362 (C) 200 0 ASCRS and ESCRS.