Refractive surgery: what the general doctor should know
- Topic
Laser surgery reshapes the cornea so glasses are not needed. It is for adults with stable refraction and healthy corneas, and it changes some later tests.
What it is
Refractive surgery corrects myopia, hyperopia and astigmatism by reshaping the cornea with a laser or by placing a lens inside the eye. LASIK lifts a thin corneal flap and treats beneath it; surface ablation (PRK) treats the corneal surface; small-incision procedures remove a disc of corneal tissue; phakic lenses and lens exchange are used for high errors. It does not prevent presbyopia or cataract.
Key facts
- Candidates: adults with a refraction stable for about a year, healthy and thick enough corneas.
- Contraindications: keratoconus or a thin or irregular cornea, uncontrolled autoimmune disease, pregnancy, severe dry eye.
- Common effects: dry eye, glare and halos at night, under- or over-correction.
- Rare but serious: corneal ectasia (progressive bulging), infection, flap problems.
In clinical practice
- After laser surgery, applanation tonometry underestimates eye pressure because the cornea is thinner; glaucoma can be missed.
- Previous refractive surgery must be reported before cataract surgery, as it changes the lens implant calculation.
- In children, refractive surgery is reserved for very high or unequal errors, decided by an expert medical-surgical board (Colombian guideline).
Next step / Initial management
- Patient asking about surgery: refer to ophthalmology for corneal topography and thickness measurement.
- Pain, reduced vision or a red eye after surgery: same-day ophthalmology (infection, flap displacement).
- Record previous refractive surgery in the medical history.
- Interpret normal-looking eye pressures after laser surgery with caution.
Test yourself
Think of the answer, then tap the question to see it.
Why must previous LASIK be considered when measuring eye pressure?
Because the thinner cornea makes applanation readings falsely low.
Which corneal condition is a contraindication to laser refractive surgery?
Keratoconus, or any thin or irregular cornea, because of the risk of ectasia.
Does refractive surgery prevent presbyopia?
No: reading glasses are still needed later in life.
Connections
Educational content; not a clinical guideline and no substitute for assessment by a health professional. For sudden visual loss, severe eye pain, a chemical burn or an eye injury, go to an emergency department at once.
Sources: Laser In Situ Keratomileusis (LASIK) (StatPearls Publishing (NCBI Bookshelf), 2023); Photorefractive Keratectomy (StatPearls Publishing (NCBI Bookshelf), 2025).
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Representative model, for educational purposes only.