SMILE (small incision lenticule extraction) differs from LASIK primarily in that:
- A It uses an excimer laser to ablate the stromal bed through a flap
- B It relies on corneal collagen cross-linking to reshape the cornea without tissue removal
- C It uses a femtosecond laser to create an intrastromal lenticule that is extracted through a small incision, leaving Bowman's layer intact over most of the cornea ✓
- D It creates a deeper flap than conventional LASIK to improve biomechanical stability
Correct answer: C. It uses a femtosecond laser to create an intrastromal lenticule that is extracted through a small incision, leaving Bowman's layer intact over most of the cornea
Explanation
SMILE (ReLEx SMILE) uses a femtosecond laser to cut two curved stromal surfaces creating an intrastromal lenticule corresponding to the refractive correction. The lenticule is extracted through a 2–4 mm arc incision. Since no large surface flap is created, most of Bowman's layer and anterior stroma are preserved, conferring better corneal biomechanical stability and less dry eye compared with LASIK. Excimer laser ablation is the mechanism in LASIK/PRK; collagen cross-linking reshapes but does not remove tissue.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.