Iatrogenic keratectasia after laser in situ keratomileusis for less than -4.0 to -7.0 diopters of myopia.

PURPOSE: To study 13 eyes with less than -4.0 to -7.0 diopters of myopia that developed central or inferior keratectasia after laser in situ keratomileusis (LASIK).

METHODS: The progress of the ectasia was determined by a series of pre- and post-LASIK topographies and the case histories.

RESULTS: Progressive ectasia developed from 1 week to 27 months after LASIK. This necessitated the wearing of hard contact lenses or penetrating keratoplasty. One eye improved for some months after photorefractive keratectomy retreatment. Two eyes in 1 patient and 1 eye in a second patient had latent keratoconus before surgery.

CONCLUSION: Laser in situ keratomileusis can cause permanent weakening and ectasia of the cornea even in eyes with low myopia.