While we certainly do a large volume of LASIK procedures at Woolfson Eye Institute, we feel that one of the most important aspects of a successful eye surgery is to make sure we match each patient with the procedure that is best for their particular situation.
In this article, we are going to discuss astigmatism, including what it is, as well as the common eye surgeries (including LASIK, PRK and more) performed on patients who suffer from astigmatism.
What is astigmatism and how is it diagnosed?
Astigmatism is a very common problem, with almost everyone experiencing it to at least some small degree. In the past, eye doctors diagnosed astigmatism by refraction, which is when the patient is asked a series of questions (such as, “Which is better, 1 or 2?”) and the optometrist obtains a reading off of an instrument called a phoropter.
A phoropter uses diopters as the unit of measurement, which provides readings in .25 increments. Using this older method, many patients are presumed to have no astigmatism.
Thanks to advancements in technologies in recent years, we now use an instrument called an aberrometer, which is used to treat patients for Custom (or Wavefront-Guided) LASIK. This instrument measures prescriptions in increments of .01 diopters. Aberrometry is ideal for objective and very precise measurements of astigmatism.
Measured with this level of accuracy, it’s extremely rare to find a patient with 0.00 diopters of astigmatism. So,
1. Almost everyone has at least a little astigmatism.
2. Astigmatism can be measured subjectively with a phoropter or objectively via aberrometry.
3. LASIK corrects astigmatism.
Which surgeries are most common for patients with astigmatism?
When it comes to correcting astigmatism, the first line of defense, surgically speaking, is LASIK. This is because LASIK is effective for a wide variety of patients, and offers the quickest recovery time. It is considered the “gold standard” for the surgical correction of astigmatism, so it’s the first option for those who are deemed LASIK candidates.
If LASIK is not an option, the primary backup plan is PRK surgery. While PRK works just as well as LASIK surgery at correcting wide ranges of astigmatism, PRK is typically Plan B simply because it includes the longer recovery time. If we find the cornea is not strong enough to make the flap necessary for LASIK, then we will likely offer PRK instead.
What about patients who are not candidates for LASIK or PRK eye surgery?
Phakic intraocular lenses are often used to correct nearsightedness in patients under 40 years old, as these patients still have the ability to adjust their focus (which is called accommodation). During this procedure, a lens is implanted inside the eye. In phakic IOL surgery, a lens is added, but the natural lens remains intact, which permits younger patients to continue to accommodate in order to see up close.
In the United States, phakic intraocular lenses currently are only approved and available to correct nearsightedness and are not available for the correction of astigmatism. Intraocular lenses used in cataract surgery, however, can correct astigmatism.
What about intraocular lenses like the ones used in cataract surgery?
There are two types of patients who can have intraocular lens implants:
– Patients who have not yet developed cataracts and are candidates for a procedure known as clear lens exchange.
– Patients who have a cloudy crystalline lens in the eye, and are thus candidates for cataract surgery where the natural lens is replaced with a synthetic one.
In cataract surgery, which is usually performed on patients 60 and older, the natural lens of the eye is replaced with an intraocular lens (IOL). IOLs for cataract patients that can correct astigmatism are called toric IOLs.
Toric IOLs can also be used as part of an elective procedure called Clear Lens Extraction (CLE) or Refractive Lens Exchange (RLE), which is when the cataract surgery is performed in order to become eyeglass-free rather than to treat a cloudy natural lens. In CLE and RLE, the natural lens of the eye is removed and replaced with a synthetic lens.
Even though goals of CLE, RLE, and cataract surgery are the same (i.e. the best vision possible), CLE and RLE are considered elective procedures, while cataract surgery falls into the medically necessary category.
Incisions on the cornea to correct astigmatism
Sometimes astigmatism can be treated during or after cataract surgery (or after an elective IOL procedure) by creating small incisions on the cornea. Corneal incisions for astigmatism can be called Limbal Relaxing Incisions (LRIs), Astigmatic Keratotomy (AK), or Arcuate Keratotomy (also AK). While corneal incision procedures like LRIs and AK can be performed as a standalone elective procedures, they are most commonly performed in conjunction with either cataract surgery or a clear lens exchange. LRIs and AK can be performed as an adjustment after intraocular lens surgery when astigmatism is measured post-operatively, or it can be performed as part of the IOL procedure when the pre-operative astigmatism level indicates the need.
The difference between AK and LRI is simply the location of the cornea that is treated; LRIs are performed on a more peripheral part of the cornea. The two procedures provide similar results.
Astigmatism correction: What is next for you?
Woolfson Eye Institute (headquartered in Atlanta, GA with nine locations around the Southeast) offers a wide variety of options for patients who require correction of astigmatism.
Our primary goal is to match each patient with the procedure that is right for them, whether that is LASIK, PRK, IOLs, or some other vision correction procedure.
No one should tell you exactly which surgery makes the most sense without providing a thorough eye examination. We encourage you to contact one of our offices today in order to schedule your complimentary consultation to see which procedure is right for you.
You don’t have to live with blurred vision due to astigmatism. Give us a call today and see why thousands of patients (including over 300 eye doctors) have chosen Dr. Woolfson for their eye surgery. Trust the Doctor the Doctors Trust! Contact us today!