Description
Photo-refractive surgery for the correction of myopia results in relative thinning of the central cornea and in rare cases may lead to delayed, progressive, corneal protrusion that results in Keratectasia or iatrogenic keratoconus. Although the creation of a corneal flap in laser in situ keratomileusis (LASIK) results in a deeper stromal excimer laser ablation, Keratectasia has also been reported with surface based photo-refractive keratectomy and following treatment of hypermetropia. Whilst a number of cases have been explained by pre-existing keratoconus, forme fruste keratoconus, or excessively deep ablations that leave thin and mechanically compromised deep corneal stroma, a number of the reported cases appear, at the present time, to be idiopathic. Risk factors and possible aetiologies are highlighted and discussed in this review.
