LASIK (Laser-Assisted In Situ Keratomileusis) is a widely recognized vision correction surgery that can effectively treat astigmatism. Astigmatism is a common eye condition where the cornea, the clear front surface of the eye, or the lens has an irregular, egg-like curvature instead of a round shape. This irregular shape causes light to bend unevenly, leading to blurred or distorted vision. LASIK reshapes the cornea to improve how light focuses on the retina, potentially reducing or eliminating the need for glasses or contact lenses.
How LASIK Corrects Astigmatism
LASIK precisely reshapes the cornea to correct astigmatism. An astigmatic cornea is shaped more like a football than a basketball, causing light to focus at multiple points instead of a single point on the retina.
During the procedure, a thin, hinged flap is created on the cornea. This flap is lifted to expose the underlying corneal tissue. An excimer laser, a computer-controlled medical device, removes microscopic tissue from specific areas of the exposed cornea. The laser sculpts the cornea’s shape according to detailed measurements from a preoperative eye scan, mapping the eye’s unique irregularities.
For astigmatism, the laser’s ablation pattern flattens steeper curves and steepens flatter curves, creating a more uniform corneal surface. This allows light to converge correctly on the retina, resulting in clearer vision. Once reshaping is complete, the corneal flap is repositioned, where it adheres and heals.
Key Considerations for Candidacy
LASIK candidacy for astigmatism requires a comprehensive eye examination by a qualified surgeon. Degree and stability of astigmatism are primary factors; LASIK can correct up to 6.00 diopters, though this can vary. Patients’ prescriptions must remain stable for at least one year prior to surgery.
Corneal thickness is another consideration. LASIK involves removing corneal tissue, so sufficient thickness is necessary for the eye’s structural integrity. If the cornea is too thin or has an irregular shape, such as keratoconus, LASIK may not be safe or effective and could worsen the condition.
Overall eye health is assessed, as certain conditions can disqualify a candidate. These include active eye infections or inflammation (e.g., conjunctivitis, uveitis), severe dry eye, or uncontrolled glaucoma. Systemic health conditions, such as uncontrolled diabetes or autoimmune diseases like rheumatoid arthritis, can impair healing and increase complication risks, making LASIK inadvisable. Patients must be at least 18 years old, as vision continues to change during adolescence.
Outcomes and Recovery
LASIK for astigmatism offers positive outcomes, with many achieving improved vision. A high percentage of patients (often around 96%) achieve 20/20 vision or better. Most patients experience rapid vision improvement within 24 hours.
Recovery involves immediate post-operative sensations like temporary blurriness, grittiness, or mild irritation, which subside within a day or two. Light sensitivity is common during initial healing. Patients are advised to avoid strenuous activities and wear protective eyewear.
While initial healing is quick, vision stabilizes over weeks to months, with full recovery taking three to six months. Temporary vision fluctuations or dry eye may occur. Although rare, some patients might require an enhancement procedure to fine-tune vision.
If LASIK Isn’t Right For You
For individuals with astigmatism not ideal for LASIK, several alternative vision correction options exist. Photorefractive Keratectomy (PRK) is a surface ablation procedure that reshapes the cornea without creating a flap, suitable for those with thinner corneas or certain irregularities. While PRK’s recovery time is longer than LASIK, it achieves comparable visual results.
Implantable Collamer Lenses (ICLs) offer another surgical alternative, particularly for high prescriptions or very thin corneas. These specialized lenses are placed inside the eye, in front of the natural lens, to correct refractive errors, including astigmatism. ICLs do not involve reshaping the cornea and are reversible.
For non-surgical solutions, specialized contact lenses or glasses remain viable options. Toric contact lenses are designed with varying powers to correct the irregular curvature of astigmatism and are widely available. Rigid gas permeable (RGP) contact lenses can also correct astigmatism, particularly for higher levels or irregular astigmatism, by providing a smooth optical surface over the cornea.