Toric IOLs: Astigmatism-correcting lens implants in cataract surgery

What is a toric IOL?

A toric IOL is a small device implanted inside your eye that corrects astigmatism so you can see more clearly. IOL stands for intraocular lens. A toric intraocular lens (and any other IOL) replaces the natural lens in your eye.

The natural lens is a disc-shaped object behind each pupil that helps you focus light. Clouding on or inside the lens is called a cataract, which can only be treated with surgery.

Most people who get toric lens implants get them during cataract surgery, so you may hear them referred to as toric cataract lenses.

What is a toric lens?

In this case, a toric lens is a specialized IOL specifically designed to correct astigmatism, one of the most common eye conditions in the world. A standard (non-toric) lens only corrects nearsightedness or farsightedness.

Astigmatism is when the curvature of your cornea (the clear front layer) or natural lens isn't perfectly round. This causes blurry vision if the curve is steep enough.

Toric IOLs are usually used to correct astigmatism in the cornea. All types of IOLs help lens-related astigmatism since they replace your natural lens during surgery.

Some people have astigmatism in both their cornea and lens. A non-toric IOL can still improve their eyesight, but it might not be as clear as it would with a toric lens implant.

There are two other types of toric lenses in eye care:

• Toric lenses for glasses

• Toric contact lenses

While glasses and contacts can help you see better while a cataract "grows," toric cataract lenses (toric IOLs) are the only type of lens that can treat the problem for good.

Different types of toric lens implants

There are several types of implantable toric lenses for cataract surgery. Each one can improve your eyesight in a unique way.

Some types of toric IOLs are:

• Monofocal toric IOL – Lens implants that correct your vision for one distance (usually far). If you wear glasses for reading and other near-vision activities, you may still need to wear them with a monofocal toric lens.

• Multifocal toric IOL – Lenses with different "zones" to correct your vision at near, intermediate and far distances. However, multifocal IOLs can increase glare, and some people find it harder to adapt to them than monofocal IOLs.

• Enhanced monofocal toric IOL – Newer lenses that improve your distance vision and intermediate vision without the potential side effects of multifocal lenses.

• Extended depth-of-focus (EDOF) toric IOL – Another lens implant that can correct multiple viewing distances with fewer side effects.

How toric IOLs work

A toric intraocular lens has more vision-correcting power in some parts of the lens than others. The more powerful parts of the lens are custom-made to match up with the angle of astigmatism (the unusual curvature) in your cornea. You can find this angle in the "axis" column of your eye prescription.

A toric IOL's special design helps offset your astigmatism, giving you sharper vision.

A standard, non-toric monofocal lens only has one correcting power across the whole lens. This is why it doesn't correct astigmatism.

Pre-surgery measurements

Your ophthalmologist (medical eye doctor) will gather information and measure your eye before recommending a toric lens for cataract surgery. That way, they can take extra precautions to make sure the lens aligns the right way inside your eye.

They'll make a note of things like:

• The exact shape of your cornea and where the astigmatism is located

• How much the astigmatism is affecting your eyesight

• How your pupils respond to light

• How the shape of your eyeball and inner eye affects the sharpness of your vision (visual acuity)

• Other eye problems, health conditions or past eye surgeries that could affect the ocular implant

Astigmatism is measured in diopters (D). More diopters equal blurrier vision.

Your eye doctor may not recommend toric lenses for cataract surgery if you have less than one diopter of astigmatism since it probably isn't affecting your vision very much.

Toric IOL surgery steps

Most IOLs (including toric lenses) are inserted during cataract surgery since the cloudy natural lens needs to be removed anyway.

The procedure to implant a toric IOL is a lot like any other IOL lens surgery, with a couple of small adjustments. Cataract surgeons will generally follow these steps:

1. Insert numbing eye drops so you can't feel anything. They may also give you medicine to help you relax.

2. Make markings on your cornea that help them align the toric IOL to your astigmatism. You'll probably be sitting upright and looking forward during this step.

3. Make a small incision in your cornea with a blade or laser.

4. Use special tools to break up the natural lens then remove the small pieces.

5. Insert the new toric IOL so it aligns with your astigmatism.

6. Tape a special patch over your eye to protect it while it heals. The small incision usually closes on its own without stitches.

Your surgeon may also ask you to use medicated eye drops and wear special glasses during the healing process.

Your eye might feel a little sensitive after surgery, but it should feel better within a couple of days.

Benefits of toric IOLs

Toric lens implants can help people with astigmatism:

• See more clearly

• Use prescription glasses or contacts less often

• Improve depth perception

• Customize their lens for multiple viewing distances

• Improve their quality of life

Patient satisfaction

Studies show that most people who get toric IOLs are happy with their eyesight after surgery. For example:

• In one study, patients with a monofocal toric IOL had an average satisfaction score of 9.7 out of 10.

• In another study, 98% of patients said they were satisfied with a multifocal toric IOL implant.

Risks and considerations

Cataract surgery with toric lenses is safe and effective, but no procedure is totally risk-free. This is true no matter what type of IOL you choose.

Some possible complications are:

• Too much or not enough astigmatism correction

• IOL rotation after surgery, which could make your vision less clear

• Secondary cataracts

• Glare or halos around lights

• Pain or swelling

• Infection, bleeding or vision loss (rare)

• IOL dislocation (rare)

Some people may be at a higher risk of IOL dislocation and other complications based on their medical history. Your ophthalmologist will talk to you about this and any other personal risks before you have surgery.

Cost of toric IOLs

While private health insurance and Medicare usually cover cataract surgery when it's medically necessary, most plans will only pay for a standard, non-toric monofocal IOL. Toric IOLs are "premium" lenses, which means you'll probably need to pay for them on your own.

On average, you can expect to pay about $1,500 per eye out-of-pocket for toric IOLs, in addition to the cost of cataract surgery. Costs vary based on the specific lens model, doctor fees and other factors.

A standard monofocal IOL will still treat a cataract and help you see better, even with astigmatism. However, you'll probably need to wear prescription glasses or contacts more often than you would with a toric lens implant.

Questions to ask your cataract surgeon

A cataract surgeon is an ophthalmologist who's specially trained to perform cataract surgery. They can answer your questions about different IOLs, cataracts and the procedure itself.

During your treatment consultation, consider asking questions like:

• Do I have the right kind of astigmatism to benefit from a toric IOL?

• Is my astigmatism strong enough for a toric lens?

• How much more will it cost if I choose a toric lens over a monofocal lens?

• How might a toric IOL improve my everyday life compared to a standard IOL?

• How much less will I need to wear glasses or contacts if I choose a toric IOL?

• Do I have a higher risk of complications based on my medical history?

• What are the other risks involved with toric lenses and cataract surgery?

Some people are a better fit for toric IOLs than others. Schedule an appointment with a cataract surgeon to see if these lens implants are right for you.

Page published on Wednesday, February 27, 2019

Page updated on Tuesday, December 17, 2024

Medically reviewed on Friday, December 6, 2024