Keratectasia

We present a case of unilateral iatrogenic keratectasia developing 10 months after bilateral laser in situ keratomileusis (LASIK) involving enhancement surgery using a broad-beam excimer laser (Summit Apex) to treat 6.6 diopters (D) of myopia.

A clinical diagnosis of keratectasia can be suspected when a patient develops unstable vision associated with irregular astigmatism. It usually occurs 6 to 18 months after LASIK surgery, but it may occur at any time.

Increased negative keratometric diopters and oblate asphericity of the PCC are common after LASIK leading to mild keratectasia.

The minimum thickness of residual stroma to prevent ectasia should be 250 mm. However, some unknown factors can still be responsible for iatrogenic keratectasias.