Astigmatism and Cataract Surgery
Astigmatism is a bend in the curve of the cornea. The cornea is the clear front part of the eye you look through. If a normal cornea is shaped round like a basketball, a cornea with astigmatism is shaped more like a football. This football shape to the cornea bends light as it passes through causing vision to be blurry. Blurry vision caused by astigmatism is separate and independent from the blurry vision caused by nearsightedness (myopia) and farsightedness (hyperopia). Regular astigmatism can be corrected or reduced as below.
There are several options to treat regular astigmatism during Cataract Surgery:
- Wearing Glasses: you may choose a standard Monofocal lens implant (IOL) for near or distance vision and wear glasses or contacts to correct your astigmatism
- Toric Lens Implant: you may choose to have a toric intraocular lens implant placed in your eye to reduce or correct your astigmatism
- Refractive: LASIK or PRK: you may choose to have refractive surgery called LASIK or PRK to reduce or correct your astigmatism
- Limbal Relaxing Incision (LRI): you may choose to have a procedure called an LRI. This is where a small incision is made in the cornea to make the cornea rounder and reduce or correct your astigmatism. These incisions may be made by hand or by using a Femtosecond Laser.
If you would like a Toric Lens, Refractive surgery, or LRIs you will need to pay extra. Medicare and Private Insurance do not pay for astigmatism correction.
Presbyopia - Loss of Reading Vision
Presbyopia is a condition that makes it hard for the eye to focus on near items, especially for reading. Distance vision may unaffected by this change. Presbyopia happens to most people as they age. It can also happen to people of any age after they have cataract surgery, especially if they choose a Monofocal or single vision lens implant for distance vision. People with presbyopia might hold a book or menu at arm’s length to see it more clearly and they often need bifocals or separate reading glasses to see clearly up close.
Options to correct reading vision during cataract surgery
Your eye surgeon may be able to reduce or correct presbyopia during cataract surgery. Insurance companies consider the correction of presbyopia elective. The goal of treating presbyopia is to reduce or eliminate your need to wear reading glasses while preserving your distance vision.
Monovision and Premium IOLs
There are two main options for correcting presbyopia during cataract surgery. One option is called monovision and the other is called a premium intraocular lens implant. Each has advantages and disadvantages. If you are interested in correcting your reading vision at the time of cataract surgery then it is important to discuss this with your eye surgeon. This may be one of the most important decisions you make about your cataract surgery, so take the time to review your options and ask questions. If you have an underlying eye condition, you may not be a candidate for presbyopia correction at the time of cataract surgery.
Custom Monovision Cataract Surgery
Monovision: Correcting 1 Eye for Distance and 1 Eye for Reading Vision
Monofocal lens implants focus light in one place (for distance, intermediate, or near vision). They offer high-quality vision but do not provide a range of vision. To treat presbyopia and achieve a blended range of vision with both eyes open, you can choose to have one Monofocal lens implant set for near vision in one eye and one Monofocal lens set for distance vision in the other eye. The goal is to improve both near and distance vision by having these two IOLs work together, with both eyes open.
Some patients do not like having one eye for distance and one eye for near. To see if you will like this kind of vision, you can do a trial with two different monofocal contact lenses before your surgery.
More Information About Monovision
Monovision and Depth Perception
In order to have good depth perception, your eyes need to be in focus together which means both see clearly when looking at the same object. This is called binocular vision. Monovision or “blended” vision can reduce depth perception because the eyes are intentionally not focusing at the same distance. In monovision, one eye is set to focus up close and the other eye set to focus far away.
Choosing which eye for distance
It is important to choose which eye you will use for distance vision, typically the distance eye is the dominant eye or the one you prefer to use. This is similar to people being right or left-handed. There are several tests that can help determine which eye is dominant. Your doctor will help you determine this at your visit if you are unsure. Once that is decided, it is helpful to try to demonstrate monovision with glasses or contact lenses to simulate the type of vision you will have after cataract surgery. Because your vision is decreased by the cataract, however, it is not possible to show you exactly what your vision will be after surgery.
Who is a good candidate for Monovision?
Monovision is good for people who prefer not to have to wear glasses for quick tasks like looking at your cell phone, a menu, a computer, or something in the distance. Please note, many monovision patients prefer to wear glasses to balance their vision for prolonged reading or for driving (especially at night) or for playing sports. If you have been wearing monovision contact lenses or had monovision LASIK, you will most likely be happy with this option after cataract surgery. Although many patients adjust well to monovision, some may find it uncomfortable. For those patients, the monovision may be reversed by refractive surgery like LASIK, but that surgery would not be covered by your medical insurance.
Premium Lens Implant Cataract Surgery
Advanced Technology or Premium Intraocular Lens Implants in Cataract Surgery
Another option to correct presbyopia and decrease or eliminate the need for reading glasses after cataract surgery is to choose a lens implant designed to provide a range of vision. These advanced specialty lens implants are called premium intraocular lenses because they allow your eye to focus far away and up close. These lenses work well in patients motivated to be independent from glasses, especially readers. Premium IOLs work best when placed in both eyes. There are different types of premium IOLs each with specific advantages and disadvantages. For example, some Premium IOLs offer better reading ability but can have side effects such as glare and halos, which may be worse at night. A thoughtful discussion with your eye surgeon can help you decide which Premium IOL is best for you.
Medicare and Private Insurance do not pay for custom vision or premium IOLs.
Custom and Premium Surgery Educational Video
In this video, Dr. Kane discusses cataract surgery options for patients who desire glasses independence after cataract surgery. He explains what astigmatism is and how the femtosecond laser and toric lens implants can help treat astigmatism with custom cataract surgery.
Dr. Kane also discusses premium cataract surgery and how special advanced technology lens implants can help patients have a range of vision after cataract surgery. He explains how these lenses may be good for patients who desire maximum freedom from glasses and don’t want to wear reading glasses.
Cataract surgery is only done once in your lifetime.
Today with so many excellent options it is important to spend time before your surgery to know what your choices are. At Tailored Eyes, Dr. Kane will review the different cataract surgery options with you and help you select which option best matches your vision goals after surgery.
To watch this educational video click HERE
Monofocal (Standard) Cataract Surgery Implant
Monofocal and Toric Lens Implants
The information provided here is for an overview of standard and toric IOLs. Please talk to your doctor for more information about which lens may be right for you.
Intraocular lenses are implanted in the eye during cataract surgery to replace the cloudy cataract lens inside the eye. There are many types of intraocular lenses available today and they each have different advantages and disadvantages. To better understand your lens implant options, first, start by thinking of your vision as having 3 different focusing needs. Your eyes need to be able to focus up close (reading distance), at an intermediate distance (computer distance), and far away (driving distance). Your eye naturally has the ability to adjust its focus at each of these distances to see clearly though you gradually lose that ability over time (see presbyopia).
These lenses provide high-quality optics but only focus light in one place (distance, intermediate, or near). As such, if you elect to have a distance vision monofocal IOL you should expect to need glasses to see at the other 2 distances, intermediate and near. Basic Monofocal IOLs are typically covered by Medicare and Private Insurances companies. They also do NOT correct astigmatism. The chance of being dependent on glasses full time to see clearly at all 3 distances is highest with a standard monofocal IOL.
Toric Cataract Surgery Lens Implant
Toric Monofocal Lenses
The toric monofocal IOL functions the same as the monofocal IOL described above however it is able to correct or neutralize the astigmatism in the eye at the time of cataract surgery. For patients with a moderate to high level of astigmatism, a toric lens implant can provide clear vision at a distance or at intermediate or near range. A toric lens implant is not covered by insurance and is considered custom vision because it requires precise positioning inside the eye to function properly. A femtosecond laser is often used to increase the accuracy and ensure proper orientation and centration of the lens. With this option, glasses are typically still needed for reading.
Premium Lens Implant Options
These lenses try to provide an expanded range of vision for patients to reduce dependency on glasses. There are many different types of lenses in this category. Some of them also come with the option for toric or astigmatism correction as described above. Some of these lenses achieve the expanded range by splitting light which may reduce contrast sensitivity.
Trifocal Premium IOL
This IOL uses advanced technology to split light to offer a range of vision spanning distance, intermediate, and near. These lenses may reduce contrast sensitivity and be associated with glare or halos but can offer a full range of vision for patients interested in being the most independent from glasses.
Multifocal Premium IOL
This IOL uses advanced technology to split light to offer a range of vision spanning distance and intermediate or distance and near. These lenses may reduce contrast sensitivity and be associated with glare or halos. Especially when blended together these lenses can offer a range of vision for patients interested in being independent of glasses.
Extended Depth of Focus Premium IOL
This type of IOL uses advanced technology to stretch the focus point to offer a range of vision spanning distance and intermediate. These lenses may provide some near vision as well but you should expect to need reading glasses for fine print. Newer versions of these lenses may avoid the glare and halo side effects associated with multifocal lenses. These lenses offer an expanded range of vision for active patients interested glasses independence.
Accommodative Premium IOL
This IOL uses advanced technology to bend the lens to offer a range of vision spanning distance and intermediate. These lenses typically do not provide near vision and sometimes do not achieve the intermediate or computer vision. These lenses are not associated with reduced contrast sensitivity or glare or halos.
Premium Light Adjustable Lens Implant
Premium Light Adjustable Lens Implant (LAL)
The light adjustable lens implant is the most customizable lens implant available today. This premium lens uses ultraviolet light to adjust the power of the lens after cataract surgery. All other premium lenses have set powers that can not be adjusted without additional surgery. This light adjustable lens gives the patient the ultimate power to fine tune their vision after surgery.
Maximum Patient Satisfaction
The LAL provides maximum patient satisfaction. It is especially useful for patients with a history of LASIK, Radial Keratotomy (RK), or high nearsightedness or farsightedness. These conditions make calculating the lens power less accurate. Therefore, these patients are at increased risk of being dependent on glasses for best vision with a fixed power lens implant.
The LAL is adjusted with UV light. Patients must wear special UV blocking glasses at all times after surgery until the final lock-in treatment is completed. The LAL is made of silicone and can be damaged if silicone oil is injected inside the eye. Silicone oil can be used to repair a complex retinal detachment.
For more information about the light adjustable lens click here.
Risks of Presbyopia Correction
As with all surgery, complications and problems can happen. In addition to all the risks of cataract surgery, here are some common or serious risks for presbyopia correction:
- You may see halos and ghost images. Or you could have night glare, double vision, or blurry vision.
- You might have trouble with depth perception (seeing which of two objects is closer) or problems driving at night.
- Premium IOLs may not work well if you have certain eye problems or large pupils.
- You may need to wear glasses at all times or just for some activities after surgery, even with premium IOLs.
Video of Femtosecond Laser Cataract Surgery with Toric Lens Implant
This is a video of a patient having LENSAR femtosecond laser assisted cataract surgery performed by Dr. Steven Kane. Caution as this video is not suitable for minors and may contain graphic eye surgery content. This video is intended for educational purposes for those who desire to learn more about cataract surgery.
Click here to watch the video: Femtosecond Laser Assisted Cataract Surgery with Toric Lens Implant
Overview of the steps of femtosecond laser assisted cataract surgery in the video:
The femtosecond laser has already been performed at the start of the video. This includes toric astigmatism correcting marks placed inside the eye and incisions in the cataract making it easier to remove. Next, incisions are made in the cornea to enter the eye. The inside of the eye is stabilized with a clear gel. The main incision is created. A circular opening is made in the bag supporting the cataract inside the eye. The cataract is separated from the bag using fluid waves. The cataract is broken into pieces and vacuumed from the eye. The residual cataract fibers are vacuumed off the bag. The lens bag is inflated with more gel and the new toric lens implant injected inside the eye. The lens is rotated into position along the femtosecond laser markings. The gel is removed and the eye sealed by swelling the cornea closed.