Penetrating keratoplasty for iatrogenic keratoconus after repeat myopic laser in situ keratomileusis: Histologic findings and literature review
Abstract
We report a patient with a sufficiently thick cornea (593 ?m) and no topographic signs of keratoconus preoperatively who developed iatrogenic keratoconus 2 months after repeat laser in situ keratomileusis (-4.00 -1.00 +- 20) performed 5 months after the primary procedure (-10.50 -1.00 +- 55). After penetrating keratoplasty, macrophotography showed severe multidirectional "macrostriae" of the stromal bed.
On histologic evaluation, excessive thinning of the residual stromal bed to a minimum of 75 ?m in the valleys and a maximum of 200 ?m at the peaks of the macrostriae were documented. The flap thickness was 225 ?m in the center.
The thicker-than-intended flap (160 ?m) is thought to be the cause of the severe complication of the LASIK procedure.