Delayed ectasia following LASIK with no risk factors: Is a 300-μm stromal bed enough?

PURPOSE: To report a case of ectasia occurring >4 years following LASIK with no risk factors and a residual stromal bed >300 μm. METHODS: A 33-year-old woman presented 4 years after LASIK with mild blurring in the left eye. Uncorrected visual acuity (UCVA) had been 20/20 in both eyes previously. RESULTS: Uncorrected visual acuity was 20/20 and 20/40 in the right and left eyes, respectively. Best spectacle-corrected visual acuity (BSCVA) was 20/20 with -0.75 +2.25 x 70° refraction in the left eye, which matched topography. Preoperative corneal thickness was 595 μm, and topography showed no risk factors preoperatively or immediately postoperatively. Calculated residual stromal bed was 342 μm and measured 400 μm with ultrasound microscopy. One year postoperatively, UCVA decreased to 20/400, and BSCVA decreased to 20/60 with refraction of -4.50 +5.00 x 90°. The patient was intolerant of contact lens wear and is considering collagen cross-linking, Intacs, or corneal transplantation. CONCLUSIONS: Ectasia can occur more than 4 years after LASIK. Its etiology is unknown and management is challenging.