Can LASIK fix astigmatism? The short answer is that in most cases, yes, like other refractive errors in the eye, astigmatism can be fixed with the ultra-precise lasers used in a LASIK procedure.
What is astigmatism?
Though it sounds rather frightening, astigmatism is no more serious than nearsightedness or farsightedness and can be corrected just as easily. In fact, the vast majority of people have some degree of astigmatism. It occurs when the front part of the eye, the cornea, is asymmetrical. The most common analogy used to describe astigmatism is that the eye will be shaped like a football rather than a baseball, or an egg rather than a ping pong ball.
Astigmatism causes vision problems the same way other refractive errors in the eye do: by distorting the light that enters the lens of the eye. If the light does not fall directly on the retina, vision will not be clear. Astigmatism prevents light from falling directly onto the retina or prevents light from falling on parts of the retina equally.
People with astigmatism can experience blurred or distorted vision at all distances, rather than at near or far distance as is common with other refractive errors in the eye.
Typical symptoms of astigmatism include eye strain, headaches, worsened night vision, or excessive squinting in order to see. A less common symptom is starbursts (sudden, bright flashes of light) in front of the eyes at night.
What causes astigmatism?
There are different causes of astigmatism: corneal and lenticular.
With corneal astigmatism, it is important to understand what meridians are in relation to the eye. If you imagine the eyeball as the face of a clock, a line connecting the 12 and 6 will make one meridian, and a line connecting the 3 and 9 is the other.
With corneal astigmatism, one of these meridians will be significantly more curved than the other.
Lenticular astigmatism occurs when the lens within the eye is distorted in shape.
Astigmatism can be present at birth, or it can develop gradually, later in life. It can also develop due to the presence of scar tissue after an eye injury. It is important to remember that astigmatism is not caused by sitting in poorly lit areas, by sitting close to a television or by squinting.
There are three different types of astigmatism:
- Myopic astigmatism. One or both of the principal meridians of the eye are nearsighted. Light will be focused more on the front part of the retina than the back
- Hyperopic astigmatism. One or both principal meridians are farsighted. Light will be focused beyond the retina, blurring your vision of objects nearby.
- Mixed astigmatism. One of the meridians will be nearsighted, and one will be farsighted. One of these curvatures will focus light too far forward on the retina, while the other will focus light beyond the retina.
Astigmatism can also be classified as regular or irregular. With regular astigmatism, the meridians will be perpendicular, meaning they meet at a 90-degree angle. In irregular astigmatism, the meridians do not meet at a 90-degree angle. The vast majority of regular astigmatism is regular astigmatism.
How does LASIK correct astigmatism?
The stigma around LASIK and astigmatism began in the early 2000s when LASIK first became popular. However, when the procedure first got FDA approval, it was not approved for astigmatism. Over the next decade, LASIK graduated from “unable to correct astigmatism” to “sometimes able to correct astigmatism”.
But as we all know, time marches on, and so does technology. The computers that control the lasers used for LASIK have gotten faster and more accurate over the last twenty years of LASIK’s popularity, and can now correct astigmatism better than glasses or contacts ever could. In other words, the people who think LASIK can’t correct astigmatism are operating on information that is nearly two decades outdated.
There are basic eligibility criteria for LASIK:
- You must be between 18 and 45 years of age
- You must suffer from some refractive error, including astigmatism
- Your eyes are healthy and you have no history of eye problems
- Your glasses/contact prescription has not changed in the last 12 months
- You are not pregnant or breastfeeding
- You do not intend to participate in contact sports for at least a month after the procedure is performed (swimming is also not recommended for the same amount of time after the procedure)
So long as you meet these eligibility criteria, you are eligible for LASIK, despite the stigma surrounding LASIK and your astigmatism.
The lasers used in LASIK surgery can be programmed to reshape the shape of the cornea to a more rounded shape. Once the cornea has been reshaped, light passing through the lens will be able to reach the retina more accurately, thus clearing the vision. LASIK works the same way with lenticular astigmatism but reshapes the lens rather than the cornea.
LASIK is typically considered a more long-term alternative to eyeglasses or contacts.
Typically, astigmatism does not exceed 3.0 diopters. Diopters are a unit of measurement for the light-bending power of a lens and denote the severity of a refractive error in the eye such as astigmatism. Astigmatism that does not exceed 3.0 can be corrected with a single LASIK surgery.
More extreme levels of astigmatism can be corrected by LASIK surgery, but they will often require a follow-up, and possibly another LASIK procedure to fine-tune the correction.
There are two different types of LASIK that can be used to correct astigmatism:
- Wavefront-Guided LASIK uses an excimer laser to normalize complex curvatures and irregularities in the cornea.
- Femtosecond LASIK will create incisions at a specific depth pre-programmed by your surgeon to correct refractive errors.
Which of these procedures is right for you depends on the type of astigmatism you have, as well as its severity.
Contact Shreveport Eye Specialists to Schedule a Consultation to Fix Your Astigmatism!
If you or someone you know is considering LASIK eye surgery for your astigmatism, the team at Shreveport Eye Specialists is ready to answer all of your questions and concerns! Give us a call at 318-771-7597, or schedule an appointment here!