It is an abnormality in which the optical surfaces of the eye are shaped like a football (oval) rather than a baseball or basketball (round). Astigmatism is a refractive error much like nearsightedness and farsightedness. The difference is that people who are either near-sighted or far-sighted will usually have most of their visual deficit at either near or far, but not both. Astigmatism, however, is a refractive error that causes blur at BOTH near and far.
How do I know if I have astigmatism?
The exact degree of astigmatism can be determined by testing the curvature of the cornea. In many cases patients are not really aware of astigmatic errors on their cornea because the human lens (ie: the cataract) often masks the full degree of the astigmatism. In real life this works quite nicely for many patients. However, once the cataract is removed and an implant is placed, the full degree of corneal astigmatism is now evident and significant distortion may occur. The best way to prevent this is to test for corneal astigmatism prior to cataract surgery and to correct it at the time of the cataract surgery.
How is astigmatism corrected?
There are two methods. The first, Limbal Relaxing Incisions, involves placing one or more incisions in the steep part of the peripheral cornea (the area directly adjacent to the white of the eye). These incisions flatten the abnormally steep curvature of the cornea and render the overall shape of the cornea closer to a baseball rather than a football. The incisions are very tiny and made with a diamond blade. They require only a few extra minutes of surgical time and are quite effective in eliminating small to medium amounts of astigmatism. Because they are placed so peripherally they are extremely safe and do not affect the optical integrity of the center of the cornea.
The second method involves implanting a special intraocular lens, called a toric lens. This type of lens can correct even large amounts of astismatism and is often used for levels of astigmatism that would not respond sufficiently to Limbal Relaxing Incisions.Toric lenses are a one-stop solution because they replace both the cloudy cataract and the distortion of astigmatism at the same time. They are extremely successful in providing crisp, clear, distortion-free vision. They are considered a “premium lens implant” meaning that their use is not covered by Medicare or PPO insurances.
What if I don’t have it corrected?
Cataract surgery is usually highly successful at removing the cataract and eliminating symptoms such as blurry vision and glare. However, if you have residual astigmatism after surgery, there is a very high chance you will need glasses or contact lenses to see clearly. Your astigmatism can easily worsen after surgery if it is not measured before surgery and managed appropriately during surgery. In such cases you are almost certain to require glasses for both distance and near vision postoperatively.
Can I have my astigmatism corrected after cataract surgery?
Yes, this is possible and generally very successful. However, this would most likely be done through Lasik (laser surgery of the eye) and the cost is about 3 times higher than doing the astigmatism correction during the initial cataract surgery.
Is perfect vision guaranteed if my astigmatism is corrected?
The vast majority of patients will have significantly better and distortion-free vision after surgery. There are other variables that affect visual outcomes such as pre-existing ophthalmic conditions and rare but possible complications of surgery. No surgery offers a 100% guarantee of success.
Should I have my astigmatism corrected if I am having surgery in one eye only?
In the vast majority of cases, your overall vision will be improved even if only one eye is done. Furthermore, if the other eye undergoes cataract surgery in the future the vision will be better yet.
Will I need reading glasses if I have my astigmatism corrected?
This is a complicated question and dependent on many issues. The short answer is that if both eyes receive “monofocal” lens implants designed for distance vision, you will certainly require reading glasses postoperatively. However, there are ways of avoiding this such as optimizing one eye for distance and the other eye for near (also called “monovision”). Furthermore, there are also premium lens implants that correct both distance, intermediate and near vision all-in-one. No matter which option you ultimately choose, correcting the astigmatism is essential for an optimal result.
Are there any risks or side effects?
In general, correcting astigmatism does not add significant risk to cataract surgery. However, there is a small risk that we won’t be able to correct all of the astigmatism and that you will still need glasses or contact lenses for optimal vision. As mentioned before, the vast majority of patients will be far more spectacle independent after astigmatism correction than not receiving it at all.
Does insurance (or Medicare) pay for astigmatism correction?
At this time, no. Astigmatism correction is considered a luxury and not reimbursable by any insurance.
What is included in the astigmatism management charge?
Refractive cataract surgery is more involved than cataract surgery alone. Usually far more testing is involved and more work and planning go into it than for routine cataract surgery. The charges for astigmatism correction includes all the different testing required to measure corneal astimatism (usually 3 additional tests). The results are fed into various computer programs which perform a vector analysis on the astigmatism and the various incisions that take place. The last stage is the cognitive planning of the procedure itself. Once a plan is customized, it can be implemented before, during or after the cataract surgery. The overall astigmatism management charge usually includes the surgical cost of the limbal relaxing incisions and/or the toric lens implant.