LASEK Surgery: How It Differs from LASIK and PRK

What Is LASEK?

LASEK (Laser Epithelial Keratomileusis) is a surface ablation procedure that occupies a middle ground between PRK and LASIK. Like PRK, it treats the corneal surface without creating a deep stromal flap. Unlike PRK, LASEK preserves the epithelial sheet by loosening it with a dilute alcohol solution, folding it back as a thin "flap," performing the excimer laser treatment, and then repositioning the epithelium over the treated surface. A bandage contact lens is then placed to protect the repositioned epithelium during healing.

LASEK vs PRK: Key Differences

In PRK, the epithelium is completely removed and discarded — the eye regenerates a new epithelium over 3–5 days. In LASEK, the epithelium is loosened with 18–20% alcohol applied for 20–30 seconds, then gently reflected as a thin sheet, and after excimer treatment, the sheet is folded back over the treated surface. Theoretically, the preserved epithelium provides a biological "bandage" that may reduce pain and speed early healing compared to PRK. However, the alcohol treatment damages many epithelial cells, so the viability of the replaced epithelial sheet is variable, and many LASEK patients' epithelium sloughs off anyway within days, resulting in a recovery similar to PRK.

LASEK vs LASIK: Key Differences

LASEK does not create a deep stromal flap — only a thin epithelial sheet is reflected. This means LASEK avoids all flap-related complications (flap dislodgment, DLK, flap striae) and does not reduce the available residual stromal bed by flap thickness. Like PRK, LASEK is suitable for patients with thin corneas that would not support safe LASIK. Recovery from LASEK is slower than LASIK (similar to PRK: 1–2 weeks for functional vision vs 24–48 hours with LASIK).

LASEK Procedure Steps

1. Anesthetic drops instilled; speculum placed to keep eye open
2. A trephine ring is applied to the corneal surface to define the epithelial treatment area
3. Dilute alcohol (18–20%) is applied within the trephine ring for 20–30 seconds, then irrigated away
4. The loosened epithelial sheet is gently reflected to one side using a blunt spatula
5. Excimer laser treatment performed on the exposed corneal surface (identical to PRK)
6. MMC applied if indicated (for high corrections to prevent haze)
7. The epithelial sheet is gently repositioned over the treated area
8. Bandage contact lens placed; worn for 4–5 days until epithelium stabilizes

Who Benefits from LASEK?

LASEK occupies a niche between PRK and LASIK that is increasingly narrowing as SMILE has emerged as the preferred flap-free procedure for patients who want faster recovery. LASEK may be specifically chosen for:

• Patients with corneas slightly too thin for LASIK but who want a surface procedure (like PRK)
• Patients with borderline dry eye who want to avoid the deep stromal nerve disruption of LASIK
• Surgeons who prefer the theoretical healing benefits of the preserved epithelial sheet
• Patients with flat corneas (K readings below 41 D) where microkeratome flap creation is technically more difficult

Recovery Timeline

LASEK recovery is essentially equivalent to PRK:

• Days 1–3: moderate discomfort, light sensitivity, blurry vision with bandage lens in place
• Days 3–5: bandage lens removed as epithelium stabilizes; discomfort decreases
• Week 1–2: vision improving but not crisp; return to desk work by Day 5–10
• Month 1–3: continued visual improvement and refractive stabilization
• Month 3–6: final visual acuity achieved

The preserved epithelial sheet may provide marginally less discomfort in the first 48 hours compared to PRK in some patients, though clinical studies show mixed results on this point.

When Surgeons Choose LASEK Over PRK and LASIK

In modern practice, LASEK is less commonly performed than either PRK or LASIK — most surgeons who perform surface ablation default to PRK (often with transepithelial PRK/SmartSurface for even smoother ablation) rather than LASEK. However, individual surgeons may prefer LASEK for specific cases, particularly flat corneas, or when they believe the preserved epithelial sheet provides a healing benefit for a particular patient's anatomy. For patients evaluating their options, LASEK and PRK are clinically similar enough that the choice often comes down to surgeon preference and experience. See the full procedures comparison guide and LASIK vs PRK.