Refractive Surgery

What is Refractive Surgery?

Refractive surgery is a set of surgical procedures designed to correct refractive errors in the eye, eliminating or reducing dependence on glasses or contact lenses. These defects include:

Myopia (difficulty seeing far away).

Hyperopia (difficulty seeing up close).

Astigmatism (distorted vision due to corneal irregularities).

Presbyopia ("farsightedness," loss of near focus after age 40).

How Does It Work?

The eye focuses light through the cornea and lens. If the shape of these structures is imperfect, the light does not focus correctly on the retina, causing blurred vision.

Refractive surgery works in two main ways:

Modifying the cornea (with laser or other techniques).

Replacing or adding an intraocular lens (in cases of high prescription or when the cornea is unsuitable).

Types of Refractive Surgery

1. Corneal Refractive Surgery (Ablative)

Uses a laser (excimer or femtosecond) to reshape the cornea and correct focus.

Most common techniques:

PRK (Photo-Refractive Keratectomy): Removes the corneal epithelium and applies a laser to the stroma.

LASIK: Creates a corneal flap, applies a laser, and repositions it.

SMILE: Removes a corneal lenticule without creating a flap (minimally invasive).

Advantages:

Fast recovery (especially LASIK and SMILE).

Effective for myopia, hyperopia, and astigmatism.

Limitations:

Not suitable for thin corneas or keratoconus.

Does not fully correct presbyopia.

2. Intraocular Lens Surgery (Non-Ablative)

A lens is implanted inside the eye without altering the cornea.

Lens Types:

Phakic (ICL)

These are placed without removing the lens (ideal for high myopia or thin corneas).

Pseudophakic: These replace the lens (as in cataract surgery).

Monofocal: These focus on distance vision.

Multifocal/Trifocal: These allow for near, far, and intermediate vision.

Toric: These correct astigmatism.

Advantages:

Option for very high prescriptions.

Reversible (in the case of ICL).

Limitations:

Higher cost than corneal techniques.

Risk of intraocular complications (glaucoma, cataracts).

Who Is a Candidate?

✅ Over 18-21 years of age (with stable prescription).

✅ Cornea of ​​adequate thickness (for ablative techniques).

✅ No serious eye diseases (advanced keratoconus, glaucoma).

Not suitable:

❌ Pregnant women (hormonal changes affect vision).

❌ Severe autoimmune diseases (risk of poor healing).