For you to know which is the right cataract procedure for you, you first need a complete, thorough eye exam and proper testing of your eyes. There is a possibility that you don’t even need cataract surgery, you may only need a new eyeglass prescription to correct your vision.
As stated before, there is never a requirement or need for cataract surgery except in very rare circumstances. You only need to consider cataract surgery when your vision is blurred to a level that limits your lifestyle or ability to work.
You should never have cataract surgery because some eye doctors say that is time for your cataract surgery (they need a new car), it needs to be done now or it will harm your eye, or you need cataract surgery just because they say so. The bottom line is that cataract surgery is an elective operation except in rare circumstances, and it is always your choice when to have surgery.
If you have decided that you are unhappy with the quality of your vision and need to see better, what are the next steps?
What Is Your Goal With Your Cataract Surgery?
Since you have decided to have surgery, what goals do you have concerning how you will see after your cataracts are removed? Is it that you just want to see better, or is it that you have always hated wearing glasses and would like to reduce or eliminate wearing glasses after the cataract surgery? Do you want to see well at a distance without glasses and only wear reading glasses for near vision, or do you hate glasses, period, and don’t want to wear any glasses for distance or reading? There are many options related to cataract surgery.
Intraocular Lens Options for Cataract Surgery
There are 6 basic types of intraocular lenses, IOLs, or implants, which are basic spherical lenses, aspheric or high-definition lenses, toric lenses, multifocal lenses, accommodating lenses, and extended depth of focus lenses.
A monocular lens has one specific strength or power to correct vision after cataract surgery. Three types of monocular lenses have a single power of focus, which are traditional monocular lenses, aspheric monocular lenses, and accommodating lenses.
Traditional monofocal spherical IOLs have been available since the 1940s and provide very good vision after cataract surgery. Through the years, the designs of the IOLs have been dramatically improved. In the late 1970s, the lenses started providing excellent results.
These IOLs are round or spherical in shape just like a magnifying lens. Traditional monofocal IOLs are covered by Medicare and insurance companies. Many eye surgeons refer to aspheric IOLs as high-definition monocular lenses. These lenses provide an increase in contrast sensitivity and less glare at night. Accommodating IOLs move inside the eye to focus on objects nearby.
Multifocal lenses provide you with near and distance vision. This works in a similar way a bifocal glass works. There are two types of multifocal lenses, which are diffractive IOLs and extended depth of focus IOLs. Diffractive IOLs create two to three separate images in the eye. One image is focused at distance and the other image at intermediate and near. You do not need to look down as with bifocal glasses.
When your eye is looking at distance, the only image the eye can see is the distance image and when you use your eyes to look at near, the only image that the eye can see is the near image. Extended depth-of-focus lenses (EDOF) work differently as the IOL provides distance and near vision by expanding the range or depth of focus of the lens.
Cataract Surgery Options
Vision Option 1
This option is considered traditional cataract surgery with a monofocal IOL. The goal of this type of surgery is to see well at a distance without glasses if your eye does not have significant astigmatism. After the surgery, you will most likely need reading glasses to see up close.
Vision Option 2
Aspheric or High-Definition Monofocal IOLs
Until recently, all lenses for eyeglasses and IOLs were spherical or round like a ball. A major refractive component of the vision system is the curvature or shape of the cornea which is not round. The cornea is aspheric in shape. The cornea is steeper in the center and flatter in its peripheral portion. A spherical lens does not bend or focus light in the same manner as the cornea of the eye. Traditional round or spherical lenses can cause high-order aberrations in the vision of a person. These aberrations can cause problems with the overall quality of your vision, especially in low-light conditions.
Part of the pre-op testing should include measurements of sphericity and aberrations of your eye. Aspheric IOLs focus light in a manner that more closely matches the way the eye focuses light. Aspheric IOLs can be used to provide sharper vision with better contrast and fewer problems with night vision. A good example would be the difference in the clarity of the picture between a regular TV and a high-definition TV. These aspheric IOLs can be used to focus your eyes for distance, intermediate, and near vision.
Some of the more common aspheric IOLs are Alcon (AcrySof IQ), Lenstec (Softec HD), Abbott Medical Optics (Tecnis Aspheric), and Bausch and Lomb (SofPost AO).
Vision Option 3
In monovision surgery with monofocal IOLs with monovision, the dominant eye is focused at distance, and the non-dominant eye is focused at near with the IOLs. The best candidate for monovision surgery is a person who has worn contact lenses with monovision correction. Monovision can cause many people to feel disoriented or dizzy wearing monovision contacts.
You need to be sure about cataract surgery as it is permanent. If you are interested in monovision and have never tried monovision, your eye doctor can have you try wearing contact lenses with monovision for some time before deciding to have your cataract surgery with monovision correction.
Vision Option 4
A modified-monovision option with monofocal IOLs is another option. The dominant eye is focused at distance and the non-dominant eye is focused at near with a mild amount of monovision. A slight amount of monovision will not cause any of the problems associated with regular monovision, which are disorientation, unstable feeling, dizziness, and loss of depth perception.
This level of modified monovision correction provides people with the ability to see prices at a grocery store, see a menu in a restaurant, and perform their daily routine activities without wearing glasses. Some people can read a book without glasses, but looking at any fine print will require reading glasses.
Vision Option 5
Toric Monofocal IOLs (Astigmatism Correcting IOLs)
The toric IOL is a great choice for people who have significant astigmatism. Toric IOLs can correct astigmatism from 1.25 diopters or more of astigmatism due to the irregular shape of the eye. As described previously, astigmatism occurs when the cornea is shaped like a football cut length-wise. The cornea is more curved in one direction versus the other. A round eye shaped like a basketball does not have any astigmatism.
The light that goes through a cornea with astigmatism is focused not on a point on the retina but on a line on the retina. People with astigmatism see ghost images or streaks around lights at night without their glasses on.
A toric IOL is designed in a manner so that it corrects astigmatism just like glasses are designed to correct astigmatism. The IOL is stronger or has stronger power in one axis or meridian and is weaker or has less power 90 degrees in the opposite axis or meridian. IOL manufacturers place indicator marks on the IOL to show the axis or direction of astigmatism. The eye surgeon uses these marks on the IOL to align it to match the astigmatism of the eye.
Before surgery, the surgeon places marks on the cornea to provide reference points to the axis of astigmatism. Some eye surgeons may use an image of the eye that is taken in the pre-op workup to show the axis of astigmatism. During the surgery, the toric IOL is placed inside the eye and aligned with the astigmatism of the eye. Common toric IOLs are Alcon (AcrySof IQ Toric), Bausch and Lomb (Trulign Toric), Star Toric IOL, and AMO (Eyhance Toric) IOL.
Vision Option 6
The option of multifocal IOLs is for people who hate wearing glasses or want to drastically reduce their reliance on glasses. Presbyopic or multifocal IOLs are designed to give distance, intermediate, and near vision through the intraocular lens. The lenses work in a similar manner to bifocal or trifocal glasses but use a completely different technology. IOLs that are designed to provide distance, intermediate, and near vision are multifocal IOLs, accommodating IOLs, and extended-depth-of-focus IOLs.
How Do Multifocal IOLs Work?
Multifocal IOLs are designed to provide vision at distance, intermediate, and near. The IOLs are designed in a way that splits the light coming into the eye and going through the IOLs into two or three images. One image is focused at distance, intermediate, and one image is focused at near.
The IOLs are designed with circular diffractive ridges, edges, or steps on the surface of the lens. The light is split or separated as it passes through these ridges, resulting in three separate images. A trifocal lens in glasses has three different strengths of lenses and you have to look down through the trifocal to see up close. The IOL is fixed inside the eye and you can’t look down into the trifocal portion of the IOL.
The multifocal IOL produces three separate images for distance, intermediate, and near. The vision is based on distance and not on direction. When you look at distance, the only image that the eye sees is the distance image. When you look up close, the only image that the eye sees is the near image. Therefore, it does not matter if you are looking up, down, or to the side; the image the eye sees is based on distance from the eye.
Proper Testing Before Surgery is Paramount with Multifocal IOLs
With multifocal IOLs, one of the most important steps before your cataract surgery is thorough testing of your eyes. The tests provide your eye surgeon valuable information essential in guiding you in choosing the best type of IOL based on how you wish to see after the cataract surgery.
For multifocal IOLs, it is very important to have a completely normal eye and vision system. The correct power of the lens needs to be chosen, as any deviation can have a significant effect on how you see. Everything needs to be right on point for a good result.
Multifocal lenses are not the best choice for everyone. It is much better to choose the proper type of surgery and IOL before your cataract surgery than have the wrong type of IOL placed in the eye. The surgery to remove an IOL and insert a new IOL can be much more difficult than the initial surgery. Also, you are putting the eye through another operation with its risks and complications. Be wise and make the proper choice for yourself. Do not just go along with some type of surgery the eye surgeon is pushing you to do. A second opinion is always a great idea.
Are You an Excellent Candidate for a Multifocal IOL?
1. You need to have a completely healthy eye.
2. There are very few aberrations in your visual system.
3. The visual axis and the center of the pupil need to be very close to the same (small angle kappa).
4. Astigmatism is minimal or the astigmatism is correctable with femto laser or toric multifocal IOL.
The Pros and Cons of Multifocal IOLs
A brain process called neural adaptation helps you learn how to see with these IOLs. The brain can adjust to the new manner in which light is being focused in your eyes. Over time, neural adaptation minimizes the rings, halos, and contrast sensitivity issues. If prior testing shows that you are an excellent candidate for multifocal IOLs, you can have a great result. Companies that make these types of IOLs are Alcon (AcrySof IQ ReStor or Panoptix) and Abbott Medical Optics (Tecnis Multifocal).
Accommodating Monofocal IOLs
Accommodating IOLs are designed to focus by moving inside the eye when you look at near or up close. The accommodating IOL moves forward inside the eye as you focus up close, as the focusing muscles inside the eye contract. The forward motion increases the effective power of the IOL to help you see at near. This is like moving a magnifying lens closer or farther away from an object, changing the focus of the magnifying lens.
The lens is designed with flexible haptics or appendages attached to the IOL which allows the IOL to move inside the eye. This IOL design has some limitations in that this movement can be minimal in some cases, limiting the amount of clear near vision. The amount of movement may reduce over time. Accommodation IOLs are Bausch and Lomb (Crystalens AO and Trulign Toric).
Extended Depth of Focus IOLs (EDOF IOLs)
An extended depth of focus or extended range of focus is a new IOL design. The EDOF IOLs or multifocal-like lens does not split the light into two separate images like the other multifocal IOLs. The EDOF IOLs provide near vision by extending the depth of focus, allowing for near vision.
The advantage of EDOF IOLs is that they do not reduce contrast sensitivity and there is less ring formation or halos around lights like regular multifocal IOLs. Another benefit of EDOF lenses is that they do not reduce reading vision in low levels of light as do multifocal IOLs.
The disadvantage of EDOF IOLs is that they do not provide as good near vision as true multifocal IOLs. The EDOF lenses do allow people to see reasonable-size print, restaurant menus, and prices at the grocery store. If you need to look at very fine print, you may need a weak reading glass. The extended-depth-of-focus IOL is made by Abbott Medical Optics (Symfony IOL). Alcon has an EDOF IOL called Vivity.
If your goal is to not wear glasses and you have significant astigmatism, there are now new options. If the eye has 1 to 1.25 diopters of astigmatism or less, the Femtosecond Laser can correct astigmatism and you can still have a multifocal IOL to correct your vision.
If you have greater than 1.25 diopters of astigmatism, then there is one multifocal IOL and one extended depth of focus IOL available that will correct the eye for distance and near vision. These are the multifocal Alcon (AcrySof Panoptix Multifocal Toric IOL), the extended depth of focus Abbott Medical Optics (Tecnis Symfony Toric IOL), Vivity Toric IOLs, and Eyehance toric IOLs. There is also the accommodating toric IOL made by Bausch and Lomb (Trulign Toric IOL).
Option of Different IOLs in Each Eye
Some people have astigmatism in only one eye or different amounts of astigmatism in each eye. You can choose to have different types of cataract surgery in each eye or different types of IOLs in each eye to maximize your vision and decrease the need for wearing glasses after cataract surgery. Your eye surgeon will go over all the different options that you may have based on the health of your eye and your goals of how you wish to see after the surgery.
After Cataract or Posterior Capsule Opacification
I get asked many times, “Do cataracts come back?” The answer is no since your natural lens has been removed from the eye. But many times people may experience blurry vision after surgery. This happens secondary to an after-cataract; the capsule that surrounded your natural lens and is now holding the IOL in place may become cloudy or opacify. This can occur in a few months or over several years. This will blur the vision similar to how a cataract blurs the vision.
Once your vision reaches a level that affects your lifestyle, a Yag laser surgery can be done to open the capsule. The Yag eye surgery procedure takes only a minute or so to accomplish. Many times you will be allowed to drive right after the procedure is completed. Yag laser eye surgery is a fast, simple procedure that instantly returns vision.
As you can see, there are many different options for cataract surgery. Traditional monofocal IOLs are covered by Medicare and insurance companies. The other types of surgeries and IOLs discussed are not covered by Medicare or insurance companies. These IOLs are designed to decrease your need of wearing glasses, not just regular cataract surgery. These lenses are not covered by Medicare and insurance companies as they do not consider it medically necessary to decrease your need of wearing glasses.
These new IOLs are designed to correct your vision, such as for astigmatism or reading. Since you are choosing to have a newer technology IOL that is designed to decrease or eliminate the need for glasses, they are not covered. Medicare and insurance companies do not believe that they need to correct your vision. They only pay for routine surgery with monocular IOLs.
Once you have decided for yourself that you are unhappy with your vision and need to see better, the next question is how you want to see after cataract surgery. Are you OK with wearing glasses after surgery or do you want to decrease your need for wearing glasses completely?
The next step is to find the right eye surgeon for you. There are many eye surgeons whose priority is only doing as many surgeries as possible. Many eye surgeons will try to tell you that it is necessary for you to have surgery right away. That if you wait, it is going to harm your eye. Many eye doctors’ offices will also push you toward the more expensive new technologies even if you are not the best candidate for that type of IOL. How do you know what to do? How do you choose your eye surgeon?
One option is that you can ask your family physician for a recommendation or ask whom they go to. Other things you can do is to make sure that your eye surgeon is board-certified, is a member of their state ophthalmology society and local societies, and has a clean record. You can always get a second opinion.
You need thorough eye testing to help you determine the best cataract surgery procedure and IOL for your specific needs and goals. Your eye surgeon should be your guide and help you make the best decision. If the eye surgeon is pushing you into surgery or a specific type of surgery or IOL, then get a second opinion.
Cataract surgery is an extremely successful operation. It is one of the most successful operations performed in the United States. Most people are thrilled with their vision after surgery. It is important to follow the right steps to get the best result.
Dr. James E. Croley III is a respected eye surgeon and an eye care pioneer. He is also the author of two books, Believing is Seeing and The Blinding of America.