Patients who need cataract surgery can choose from several types of intraocular lenses. Focus asked Nandini Venkateswaran, MD, a member of the Cornea and Refractive Surgery Service at Mass Eye and Ear, to help break down the options.
Cataracts are a leading cause of blindness. Once a person experiences significant symptoms, it might be time to get surgery, which involves removing a transparent piece of tissue in the eye called the lens because it has become cloudy. The lens is then replaced with an artificial lens, or intraocular lens. Prior to surgery, a patient can choose from several types of intraocular lenses that vary in costs and focusing powers.
These lenses can remain in patients’ eyes for the rest of their lives, so how do people make this difficult choice?
Dr. Venkateswaran, an ophthalmologist who sees patients at the Mass Eye and Ear, Waltham location, said this conversation typically starts during a surgical consultation. There, she will learn about the patient’s treatment goals. Some might be on a computer screen all day for work and want to see it better; others may be avid runners or golfers and require a lens that can fit their active outdoor lifestyles. A patient’s anatomy or existence of other eye conditions can also play a major role in determining the best selection.
“In the past decade, we’ve seen an explosion in the number of lens options available to patients,” Dr. Venkateswaran told Focus. “We help patients come to a choice by learning what their day-to-day life is like and what they want to get out of their vision after cataract surgery.”
At the time of cataract surgery, patients have a one-time opportunity to select lens that will give them the best vision and this can be a challenging choice. Dr. Venkateswaran explained the lenses a patient can choose from, and who might benefit most from each type.
The most common type of intraocular lens is a monofocal lens. Typically covered by insurance, the lens offers one focusing distance, meaning it can either best focus at distance, intermediate or close up. Therefore, a patient who chooses a long distance focus will need to wear reading glasses for all up-close tasks.
“Some patients don’t mind the dependence on glasses; they’ve worn glasses their whole lives so their lifestyle would not change,” said Dr. Venkateswaran. “Others may want to use cataract surgery as the time to reduce their reliance on glasses.”
If a patient had previously gotten cataract surgery on one eye and received a monofocal lens and now needs cataract surgery on the other eye, a second monofocal lens is often recommended to ensure consistency in vision, either focused at a distance or with a blended intermediate/close-up target.
For people with lifestyles where only one focus distance may be less than ideal, they can choose from several types of premium lenses.
Multifocal, trifocal or presbyopia (farsightedness)-correcting lenses
Multifocal lenses or the newest available trifocal lenses, are good options for people with overall healthy eyes without other diseases. The trifocal lens splits light in a way to give a person a larger range of focus for multiple distances: far, intermediate and near. This can dramatically reduce a person’s need for glasses on a daily basis.
Many patients prefer these lenses due to their overall vision improvement and ability to be glasses-independent according to Dr. Venkateswaran. But, she cautioned one factor that concerns some is the appearance of glare or halos at night, such as when viewing a bright headlight or street light when driving. Glare and halos can fade with time as patients “neuroadapt,” meaning their brain adapts to this phenomena (like they might get used to a floater), often over six months.
“Some patients might say, ‘If I can get both distance and reading with a trifocal lens, that’s the lens I want,” said Dr. Venkateswaran. “Others might drive a lot at night and not want any glare or haloes whatsoever, and therefore opt for a monofocal lens.”
Extended depth of focus lenses
Extended depth of focus lenses, unlike monofocal lenses, stretch and shift light in a way to provide patients with a larger range of vision. With these lenses, patients receive excellent distant and intermediate vision, and functional near vision. They might, however, not be completely independent of glasses, such as when reading small print or in dim light.
This lens differs from the trifocal because of the way it manipulates light rays, and with certain lens platforms, there’s less risk of glare and halos.
“This is a lens that can benefit a lot of people: patients who really want to lead an active lifestyle and spend a lot of time on the computer, who might not mind throwing on a pair of reading glasses in some settings,” said Dr. Venkateswaran.
Unlike trifocal lenses that require pristine eye health, patients who have other eye conditions, such as mild glaucoma or epiretinal membranes, can be candidates for extended depth of focus lenses.
Astigmatism-correcting lenses, or toric lenses
Patients who need cataract surgery and have astigmatism may benefit most from a premium lens called a toric lens. Astigmatism causes a change in the physical structure of the cornea, causing it to be a figure-eight or football shape. That means a traditional lens implant will not address all of the patient’s astigmatism. A toric lens is implanted into the eye after cataract surgery and is oriented to the axis needed to correct the astigmatism. Toric lenses are available not only as a monofocal platform but also in trifocal and extended depth of vision platforms, providing patients who have astigmastism with several options.
How to choose?
It’s important to first keep in mind that no lens is perfect, and some patients might require reading glasses for tiny print even if opting for a newer technology. Next, patients should do their homework, and visit resources like the American Academy of Ophthalmology for more information.
“No lens is as perfect as the one you’re born with,” said Dr. Venkateswaran. “But we as surgeons have a toolbox of lenses available that we can match to your visual need and desires as well as lifestyle.”
For some patients, cost is a big factor. Premium lenses are not covered by commercial insurances or insurances like Medicare and require out-of-pocket payments, as they are all considered elective options. The out-of-pocket costs can also include surgery performed with femtosecond lasers, a technology which helps standardize some of the steps involved in cataract surgery and intraocular lens placement as well as correct lower degrees of astigmatism that are harder to correct with manual surgery. Out-of-pocket costs can also include the use of intra-operative aberrometry, which provides real-time measurements of the eye once the cataract is removed where a surgeon can confirm the patient’s lens choice to ensure the desired vision outcome.
Some patients may choose to get a premium lens and realize it does not fit their lifestyle as they hoped and want to go back to their glasses. “With any of these premium lens technologies, as surgeons we want patients to be happy first and foremost. We can always take out the premium lens and implant a monofocal lens if needed,” said Dr. Venkateswaran.
“At the end of the day, it’s important for patients to do their research and be aware of any potential downsides. Spend one-on-one time with your surgeon discussing the surgical procedure and all lens options.” she said. “Thankfully, research shows that most people are happy and would get these surgeries done again.”
About the Expert:
Nandini Venkateswaran, MD, is a member of the Cornea and Refractive Surgery Service at Mass Eye and Ear. She specializes in complex cataract surgery, corneal transplantation, laser refractive surgery, corneal cross-linking, anterior segment reconstruction and diagnosing and treating conditions of the eye’s surface. She sees patients at our Waltham location and Main Campus in Boston.