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Astigmatism
surgery
LASIK · SMILE · Trans-PRK · Toric lenses
Astigmatism is rarely corrected on its own. It usually comes with myopia (short-sightedness) or hyperopia (long-sightedness), and is treated during the same operation. What sets it apart is the precision it demands on the axis: an error of a few degrees is enough to degrade the result.
Eligibility
Does this apply to you?
These criteria point the way; they do not decide. Only the pre-operative assessment, which measures the actual geometry of your eyes, can settle the question.
What the operation corrects
Schematic cross-section: the oval shape of the cornea is exaggerated
Favourable profile
- Regular astigmatism, meaning its two axes are perpendicular
- Corneal topography with no suspicious irregularity
- Refraction stable for two years, with an axis that is reproducible from one measurement to the next
- A cornea thick enough for the intended correction
- If you are having surgery on the natural lens, a toric lens corrects the astigmatism in the same procedure
What rules it out or delays it
- Irregular astigmatism, which often points to keratoconus and rules out laser treatment
- Confirmed or suspected keratoconus: this is the main contraindication
- Astigmatism caused by scarring or injury, which calls for a different treatment
- An axis that varies from one measurement to the next, a sign of an underlying irregularity
- Refraction not yet stable, pregnancy or breastfeeding
Techniques
The options to consider.
None is better than the others in absolute terms: each one suits a specific anatomical situation.
LASIK
Corrects astigmatism combined with either myopia or hyperopia. The laser selectively regularises the curvature along the axis.
SMILE
Indicated for myopic astigmatism and, since 2024, for hyperopic astigmatism on the VisuMax 800. The lenticule that is removed includes the axis correction.
Trans-PRK
For thin corneas or eyes exposed to knocks and impacts, when the astigmatism is moderate.
Toric lens
During cataract surgery, PreLex or a phakic lens procedure: the lens itself carries the correction, aligned along a precise axis.
What you should know
The point that is too rarely explained.
With astigmatism, the critical point is not the power being corrected but its orientation. That is why the assessment repeats the measurements and checks that they are reproducible. It is also why topography plays a diagnostic role here as much as a technical one: it is what distinguishes regular astigmatism, which can be operated on, from an irregularity revealing keratoconus, which cannot.
SFO information leaflets (in French)
Published by the French Society of Ophthalmology (Société Française d'Ophtalmologie), they describe the procedure, its results and its risks. They form the basis of informed consent and do not replace a consultation.
Frequently asked questions
What I am asked most often.
Can astigmatism be operated on by itself?
Yes, although it usually comes with myopia or hyperopia and is corrected at the same time.
What is the difference between regular and irregular astigmatism?
Regular astigmatism has two perpendicular axes and corrects well. Irregular astigmatism reflects a deformation of the cornea, often keratoconus, and rules out laser treatment.
Can high astigmatism be operated on?
Beyond a certain degree, the laser reaches the limits set by corneal thickness. A toric lens then becomes the solution.
What is a toric lens?
An intraocular lens whose power varies along an axis, implanted during surgery on the natural lens to correct astigmatism at the same time.
Can astigmatism come back?
The correction is stable if the astigmatism was stable. A toric lens can, rarely, rotate, and may then need to be repositioned.
Find out whether it is possible for you
The questionnaire gives you a first indication in three minutes. The pre-operative assessment measures what cannot be guessed: your topography, your corneal thickness and the condition of your retina.
Dr Emmanuel Halimi
Ophthalmic surgeon · RPPS 10100555084 · Medical Council of Hauts-de-Seine no. 92/23003
Page written and approved by the surgeon.
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