In SMILE (small-incision lenticule extraction) surgery, the femtosecond laser creates two curved cuts within the corneal stroma to isolate a refractive lenticule. The main theoretical advantage of SMILE over LASIK regarding corneal biomechanics is:
- A SMILE ablates more anterior stroma, preserving the stronger posterior stroma
- B SMILE has larger optical zones than LASIK, reducing spherical aberration
- C SMILE preserves the anterior stromal lamellae (Bowman's layer and anterior stroma) as no flap is created, maintaining more corneal tensile strength ✓
- D SMILE does not require any laser ablation, eliminating thermal damage to keratocytes
Correct answer: C. SMILE preserves the anterior stromal lamellae (Bowman's layer and anterior stroma) as no flap is created, maintaining more corneal tensile strength
Explanation
The anterior stroma and Bowman's layer bear the greatest tensile load in the cornea. LASIK creates a large flap that severs anterior lamellar fibres over 270°, significantly reducing corneal tensile strength. SMILE creates only a small 2–3 mm keyhole incision, preserving the full anterior cap including Bowman's layer and anterior stroma, which provides better biomechanical stability. SMILE does use laser ablation (lenticule dissection) and does not inherently have larger optical zones.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.