A 25-year-old myopic patient undergoes LASIK. During microkeratome pass, a partial flap with a hole in the center is created. This complication is called:
- A Free cap
- B Incomplete flap
- C Buttonhole flap ✓
- D Epithelial defect
Correct answer: C. Buttonhole flap
Explanation
A buttonhole flap occurs when the microkeratome blade creates a flap that has a central full-thickness hole, typically due to excessive corneal steepness (K > 47 D). It is distinct from a free cap (complete circular flap cut with no hinge) and an incomplete flap (insufficient travel of the microkeratome). Buttonholes are associated with increased risk of irregular astigmatism and haze.
Reference: AAO BCSC Section 13: Refractive Surgery, 2022-2023 ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.