Unexpected flap thickness in laser in situ keratomileusis.

We report a case of an unexpected thick flap during laser in situ keratomileusis (LASIK) that led to abandonment of surgery. This report illustrates the importance of stromal bed measurements after flap creation in LASIK. A thicker-than-expected flap can lead to a thinner-than-anticipated residual cornea and subsequent ectasia or even perforation during laser ablation. It is possible that reports of ectasia in normal thickness corneas reflect thicker-than-anticipated flaps.