When it comes to cataract surgery, intraocular lens (IOL) selection is typically the most important decision a patient can make. IOL correction of hyperopia, myopia, presbyopia, and astigmatism are dependent on patient vision goals when approaching cataract extraction. Here, we will discuss considerations for presbyopia correction during cataract surgery.
Overview of multifocal IOLs
Presbyopia refers to the gradual loss of accommodation encountered by most patients, as they age, starting in their fifth decade.1 Whether one is farsighted or nearsighted, presbyopia will occur; typically, presbyopia is treated with the use of reading glasses.2
In cataract surgery, the natural lens of the eye is removed, and in order to restore vision, it is replaced with a lens implant.1 These lenses come in various levels of power, depending on the needs of the patient. The power determines the distance at which the patient can focus, whether that be near or far.
Traditionally, a patient would have to pick whether they would like to be nearsighted or farsighted with a monofocal lens and then be prescribed a pair of glasses. However, this has now changed due to the innovation of multifocal (or presbyopia-correcting) IOLs. Multifocal IOLs allow a patient to be in focus at far, near, and intermediate distances.3 The reasoning behind this is the lens’ ability to refract or diffract light at any focal point, typically using many ring-shaped optical zones.
As you can see in Figure 1, a monofocal IOL contains no diffraction rings, whereas a multifocal IOL contains various optical rings.4 There is also the option of an accommodating IOL, which is intended to work in a similar fashion as the eye’s zonules contract and relax during periods of near and far focusing.
Figure 1: Image - LA Sight
Considerations for presbyopia correction with cataract surgery
Given that multifocal IOLs allow one to see from various distances, we can now correct presbyopia with cataract surgery. These IOLs are generally used for patients with visually significant cataracts, although they can be used for patients without cataracts, in a similar procedure, called a refractive lens exchange (RLE).
Most often, an ophthalmologist will not correct a patient’s presbyopia with cataract surgery unless the patient’s vision is impaired by a cataract. It is important to counsel patients that while cataract surgery poses minimal risk, there is a risk nonetheless. This being the case, undergoing a procedure for a condition that could still be corrected with the use of eyeglasses is not the preferred conservative option for most patients.
Moreover, patients with comorbid conditions, such as glaucoma and age-related macular degeneration, may not be suited for multifocal IOLs due to their vision limitations. For example, a patient suffering from macular degeneration often has deficient central vision.1 Thus, the patient will not reap the benefits of a multifocal IOL, as their vision has already deteriorated due to factors other than the lens of the eye.
For patients who need excellent near or distance vision, a monofocal IOL is preferred.3 This is because there may be a degradation of contrast sensitivity, or the ‘sharpness’ of vision with multifocal lenses. On the other hand, for patients who are certain they don’t want to wear glasses and are more focused on a comfortable lifestyle, a multifocal IOL is the better choice.3
In addition, presbyopia correcting IOLs can also have visual side effects, such as glare and halos at nighttime. Patients must be extensively counseled on this, as some may be very bothered by these visual aberrations, despite the benefit of minimal-no need for reading glasses.
Simply put, the ideal patient for presbyopia-correcting cataract surgery is one with no significant ocular comorbid conditions, a desire to not require corrective lenses at any distance, and willing to compromise visual acuity at any one distance for acceptable visual acuity at multiple distances.3
Multifocal IOL options
There have been a variety of newly developed FDA-approved lenses currently available for patients to choose from; these include Alcon’s PanOptix® Trifocal IOL and Vivitiy® EDOF (extended depth of focus) IOL, and Johnson & Johnson’s SymfonyTM EDOF IOL and SynergyTM IOL. The PanOptix lens is marketed as the first and only trifocal lens in the United States, and has been implanted in over 125 million patients.5
In addition, studies states that 99% of users would choose the same lens again, and that 80.5% of users never used their glasses postoperatively.4 Alcon’s Vivity lens is the first and only non-diffractive EDOF IOL, meaning that the lens does not have rings, and “uses all available light to create a continuous, extended range of vision.”6 According to a large clinical trial, users achieved a mean distance vision of 20/20, intermediate vision of greater than 20/25, and near vision of 20/32.8
In addition, when surveying patients on incidence of dysphotopsias, 0% of 106 patients were bothered by glare, and only 1-2% were bothered very much by halos and starbursts, respectively.7
On the other hand, Johnson & Johnson’s Symfony EDOF IOL claims to allow patients to see clearly across a full range of vision. Instead of splitting light into distinct focal points, the lens “elongates focus, resulting in an increased depth of field…to deliver a full range of vision while maintaining high image contrast.” According to studies of this IOL, 85% of patients wear glasses minimally or not at all postoperatively.8
Lastly, the Synergy IOL claims to have the widest range of continuous vision, along with very sharp near vision.9 In addition, the lens allows for enhanced image contrast in both day and night conditions. The lens is designed using wavefront technology, which aims to correct the visual distortion that can cause glare, halos, and lesser visual quality.9
With any multifocal IOL, there are drawbacks that come with the ability to see at many distances. One compromise is that the quality of vision may not be as clear as it would be should a patient opt to use a monofocal lens. Also, night vision may be reduced to a degree, making driving at night difficult, as light has the potential to bounce off the various rings of the IOL, (the same phenomenon which produces halos and glare).2
The cost of the lenses is also a factor to consider, as they are typically not covered by insurance; most lenses cost anywhere from $1,500 to $4,000.10
Conclusions
Today’s advances have made it possible to treat presbyopia with cataract surgery and implantation of multifocal IOLs. While not all patients are ideal candidates, it is important for physicians to discuss with their patients the available options to ensure an informed decision-making process. As surgical technology within ophthalmology continues to evolve, we hope innovation will continue surrounding multifocal implants so that we can provide every patient with the “best set of eyes” possible.
References
- Allen, Richard C., and Richard A. Harper. Basic Ophthalmology: Essentials for Medical Students. American Academy of Ophthalmology, 2016.
- Friedman, Neil J., et al. Review of Ophthalmology. Elsevier, 2018.
- Thompson MD, Vance. “Multifocal Intraocular Lenses: Restor and Tecnis Multifocal Iols.” All About Vision, All About Vision, 5 Jan. 2022, https://www.allaboutvision.com/conditions/multifocal-iols.htm.
- LA Sight . “Cataract Surgery Lens Implant Choices - See Well without Glasses.” LA Sight, 13 Nov. 2018, https://www.la-sight.com/services/cataracts/lens-implant-choices/.
- Alcon. “Benefits of the Alcon PanOptix® Lens.” What Is the Alcon PanOptix® IOL? | PanOptix® IOL, https://panoptix.myalcon.com/cataracts/panoptix-iol/about-panoptix-iol/.
- Galiani Ophthalmology Associates . “Vivity IOL (Advanced Technology).” Galiani Ophthalmology Associates, 22 Mar. 2021, https://www.galianiophthalmology.com/vivity-lens-new-premium-iol#:~:text=Alcon's%20proprietary%20non%2Ddiffractive%20technology,and%20filters%20blue%20light%20rays.
- MyAlconProfessionals . “AcrySof.IQ Vivity .” Alcon Eye Care for Healthcare Professionals, https://professional.myalcon.com/cataract-surgery/intraocular-lens/vivity/.
- Johnson and Johnson Vision . “Tecnis SYMFONYTM IOL.” Johnson & Johnson Vision, 29 Nov. 2021, https://www.jnjvisionpro.com/products/tecnis-symfony%C2%AE-iol.
- Johnson and Johnson Vision . “Tecnis SYNERGYTM IOL.” Johnson & Johnson Vision, 8 Nov. 2021, https://www.jnjvisionpro.com/Synergy.
- New Vision Eye Center. “How Much Does Laser Cataract Surgery Cost?” New Vision Eye Center, 17 Apr. 2018, https://www.newvisioneyecenter.com/cfiles/blogs/NVBlog_041718.cfm.
