Upgrading to Multifocal and Toric IOLs
8:57 PM
In today's world, cataract surgery is typically met with excitement moreso than dread. Why? Many patients have been waiting for years to be more independent from glasses and contact lenses, and the intraocular lenses (IOLs) used after cataract removal can greatly reduce their need for glasses after surgery. If you or a loved one is undergoing cataract surgery, the choices for IOL designs can be overwhelming. Do you want multifocal implants, to help you see with a range of vision both near and far? Do you need toric implants to reduce your astigmatism and limit the chance you'll need glasses for clear driving vision? These options exist, but they are options you have to choose to pursue out of your own pocket. Insurance only covers standard implants--they won't correct your reading vision, and they won't correct moderate to high amounts of astigmatism; you will need glasses after cataract surgery for a majority of your visual needs with a standard implant. How do you know if pursuing premium IOLs is worth your investment? Your cataract surgeon and your personal optometrist that is comanaging your care can walk you through the best choices for your individual needs. Today we're bringing you the basics courtesy Dr. Dawn Williams, an optometrist at See Clearly Vision who routinely provides pre- and post-operative cataract care, and Irina Price, their surgery coordinator.
What can a patient expect with a successful multifocal IOL after surgery?
Success, from my perspective, is defined as increased functionality and decreased dependence on spectacles and/or contact lenses. I would suspect we are about 95% successful. Patients have to know that they will still need to use glasses sometimes; reading small print, reading in dim lighting, perhaps even for crystal clear driving vision. Success is highly dependent on setting realistic expectations prior to surgery. Preparing a patient for real expectations is a combined effort of every staff member who meets with the patient. From the surgeon, to optometrist to surgical counselors. This is where surgical counselors can play a big part in helping patients understand their expectations in comparison to their goal or surgical outcome. It is important for each patient to understand that the goal is to reduce dependency -- not eliminate the need for glasses. When a patient selects a multifocal they expect to be glasses free, however, when they’re sitting down at the sewing machine or trying to remove a splinter from a grandchild’s hand, they need to be educated that they may need assistance with reading glasses for these high visual demand situations.
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| Multifocal IOLs have rings of distance and near vision to achieve a range of vision near to far. via |
Are there any side effects with multifocal IOLs?
The possibility of halos at night are a negative side effect of multifocal IOLs due to their multiple ring design. Halos and glare aren't a big issue with the other type of near focusing implant, accommodating IOLs, but these implants tend to have more trouble with unclear near/reading vision. The implant has to move within the eye, and if the patient's ocular tissue doesn't adequately support this movement then reading vision will be limited. This is something that doctors can't really screen for, which is why there is such variability in the success rate of accommodating IOLs. This is where every doctor and eyecare provider who comes in contact with the patient needs to be educating the real expectations for what each implant can and can't do. Here's an example of our dialogue:
“Mrs. Smith, a multifocal is going to give you a range of vision, however, the goal is to reduce your dependency on glasses. That being said, you still may need reading glasses for doing fine hand work or to correct residual astigmatism at distance”.
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| Accommodating IOLs have to flex within the eye to focus your vision between near and far. The range of vision achieved post-operatively depends on the anatomy of the patient's eye and how much flexure is accomplished. via |
Can someone with high astigmatism or high prescription have multifocal IOLs? Or are there certain Rxes that are just not possible for this type of lens?
High amounts of cylinder (astigmatism) or highly ametropic (high prescription) patients are not excluded from having premium lenses unless they have corneal scarring, retinal pathology, or amblyopia. As long as the necessary IOL is within the range of available lenses, even in cases where the IOL would leave some residual refractive error, if it will reduce the patient's dependency and increase functionality it may be a good option. Patients with a high risk of residual prescription need to understand though that for their best vision they will still need glasses; these implants will reduce their need, but they won't give them crystal clear vision.
What conditions would prevent a patient from being a good candidate for multifocal IOLs?
Corneal scarring, retinal pathology like diabetic retinopathy or macular degeneration, and amblyopia (lazy eye) are a few things that would preclude a person from a premium IOL. Both eyes have to have a high level of function to be successful in these implants. The ring design of a multifocal IOL can greatly increase your risk for glare or halos at night or in dim lighting, so if the retina or cornea has a condition that causes visual distortion, the chance that the patient will be visually successful in this implant is very low. In the process of assisting patients in selecting their IOLs, physicians are able to guide patients towards certain lenses based on their overall ocular health. During the pre-op surgical evaluation, the doctor carefully examines the retina with dilated views and OCT imaging, and performs corneal topography for prospective multifocal patients; these results will help guide a patient towards, or away from, a premium IOL.
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| What's hiding behind that cataract? A thorough retinal examination is needed to make sure each patient is a good candidate for premium IOLs. |
When do you recommend monovision implants (one eye set for reading, one eye set for distance) versus multifocal (both eyes see a range of distance and reading) IOL implantation?
The most successful IOL recommendations are made based on the patient's prior visual correction and their goals. If a patient has had monovision before in their contact lenses with good success, it's generally very easy to achieve success with a monovision IOL surgery. But if a patient has never worn monovision before, it is not their best choice. It's very difficult to demonstrate monovision with the presence of a cataract in one or both eyes, so the patient won't be able to try it out in contact lenses prior to surgery in most cases to know if they like it or not. If a patient has not had monovision in the past, we would like recommend presbyopic (multifocal or accommodating) IOL
When do you recommend toric (or astigmatism) IOLs?
A good candidate for a toric IOL will have a cylinder power of -1.25 to around -5.00 diopters.
When do you recommend Laser Assisted cataract surgery?
Laser-assisted cataract surgery is FDA approved for the treatment of low amounts of astigmatism, with a maximum correction of up to -1.50 diopters. It can also be beneficial in patients with very dense cataracts or corneal endothelial disorders (Fuch's Dystrophy). It’s important to remember that the goal of laser-assisted cataract surgery is to help reduce patient dependence on glasses following surgery. Patients who have worn contact lenses all their lives may be more inclined to select laser-assisted cataract surgery to reduce their dependence on eyewear as that is the goal of contact lenses in the first place -- to reduce your dependence on glasses. As a surgical counselor, I find that many contact lens patients are excited at the thought of less dependence on contacts and glasses after surgery.
What should optometrists referring their patients for cataract surgery talk to their patients about before the referral?
Discuss the possible IOL options and realistic expectations for what premium IOLs can do; as an optometrist you've been caring for your patient for years and know their personality and needs better than anyone! Many patients that are referred to our offices have been utilizing the benefits of monovision for years. It is beneficial if the referring OD is able to discuss with the patient whether or not they would like to maintain monovision following surgery as well as provide the contact lens prescription the patient has worn in the past to achieve success.
When an optometrist takes over the post-operative care for their patients after premium IOL implantation, are there any common patient issues with these types of lenses that ODs should be familiar with or know how to troubleshoot?
Reassure the patient that vision after multifocal and accommodating IOLs keeps changing and improving after surgery. For most, the best vision will be achieved about 4 weeks after surgery, so don't panic if the vision is not quite perfect at the 1 week post-op. The brain needs time to learn to use it's new vision, and there is still healing going on from the surgery itself in the first few weeks, so we don't expect perfect clarity right away. Always remind pre and post-operative patients that healing takes time, patience and rest. Having worked as a technician and surgical counselor, I’ve often been known to remind patients that if they had knee surgery they wouldn’t be up running a marathon the next day so they need to give their eye the same amount of time to heal. It helps remind patients that they need to be realistic about healing and not consider their cataract surgery to be providing them with a bionic eye.
Check out Dr. Williams, Irina Price, and the whole See Clearly Vision team at their website and on their Instagram account to learn more.
1 comments
This is very informative. Thank you Dr. Williams!
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