The intraocular lens (IOL) landscape is dynamically changing for the cataract and refractive surgeon.
Over the course of my last five years in ophthalmology as both a trainee and now an attending, the armamentarium of available IOL technologies has rapidly expanded. In fact, the IOLs that I use in practice today differ greatly from those I was offering my patients just six months ago.
This surge of new IOL technologies is now enabling surgeons to match patients with a lens best suited for their specific lifestyles, enhancing patients’ range of vision while at the same time limiting any quality-of-vision trade-offs. I’ll review the currently available premium options that all graduating surgeons can start implementing in their cataract practices.
Toric IOLs
Astigmatism correction is of paramount importance when trying to provide high-quality uncorrected visual acuity. Toric IOLs should be offered to all patients with clinically significant astigmatism, and surgeons should aim to leave <0.5 D of residual astigmatism for all patients. Although low levels of astigmatism can be corrected with manual or femtosecond laser–assisted arcuate incisions, correction of higher levels of astigmatism is more reliable and consistent at the IOL plane.
In my practice, I begin implementing toric IOLs in patients who have >0.75 D of against-the-rule astigmatism and >1.50 D of with-the-rule astigmatism. Diagnostic imaging platforms provide reproducible measurements of the magnitude and axis of astigmatism (including measurements of anterior and posterior corneal astigmatism) and can confirm that the astigmatism is regular in nature. You can also utilize intraoperative aberrometry to confirm the IOL power and axis of the toric IOL placement.
The optics of toric monofocal IOLs are equivalent to that of non-toric monofocal IOL platforms, with the only potential downsides being out-of-pocket costs associated with toric IOLs and the rare occurrence of post-operative IOL rotation or refractive surprises. Presbyopia-correcting IOL platforms also come in toric versions, which augments the patient pool in which you can use these lenses.
Presbyopia-correcting IOLs
Presbyopia-correcting IOLs have helped surgeons provide patients with greater ranges of vision and less dependence on glasses for a majority of daily activities.
Trifocal lenses. Modern-day trifocal IOLs with diffractive optics provide the widest range of vision at distance, intermediate, and near, along with more tolerant defocus curves compared to older-generation multifocal IOLs that behaved largely like bifocal lenses.
However, trifocal lenses can still be associated with:
- Infrequent use of reading glasses when reading small print
- Loss of contrast sensitivity in mesopic lighting conditions
- Glare and halo phenomena at night — albeit less so than older-generation multifocal IOLs
As such, patients should be counseled clearly about any potential side effects as well as the process of neuroadaptation to these IOLs. The dogma of “under promise and over deliver” often proves to be very valuable for patients receiving these IOLs, as they are pleasantly surprised by the improvement in their lifestyle with a full range of vision, despite some mild side effects.
Extended depth-of-focus (EDOF) lenses. These IOLs are presbyopia-correcting lenses that also increase range of vision in patients and offer excellent distance and intermediate distance vision with functional near vision. This lens platform is better tolerated in patients with co-existent pathologies such as mild epiretinal membranes, glaucoma, or a history of prior refractive surgery.
Patients should be counseled on the likely need for glasses during most close-vision activities, depending on font size, lighting, and working distances; however, EDOF lenses do have the added benefit of less glare and halos and less of a decrease in contrast sensitivity depending on the IOL platform used.
Light-adjustable IOLs
The light-adjustable lens (LAL) is a novel IOL technology for the customization of vision following cataract surgery. Its unique photosensitive IOL platform allows for post-operative adjustment of IOL power and toricity using an office-based UV light system. As such, the surgeon can perform an in-office treatment and “lock in” patients once they are satisfied with their vision.
Compared to the intricacies involved with the placement and alignment of toric IOLs, the LAL’s ability to correct up to 2D of astigmatism can help simplify its management in patients. In addition, the LAL has intrinsic EDOF properties that can enable some patients to obtain larger ranges of vision, but post-operative adjustments achieving monovision or blended vision in the nondominant eye can also be performed
For patients who cannot commit to a particular vision target (distance, near or intermediate), treatments are reversible and titratable until locked in, offering an additional level of flexibility that is not possible with other IOL platforms. This IOL also shines in post-refractive patients who can experience refractive surprises due to the inherent challenges in IOL calculations, which can now be titrated post-operatively with the LAL.
Take advantage of new technologies. The range of available premium IOLs might seem overwhelming at first to a new surgeon. However, by carefully studying the properties of these exciting options, you can customize your IOL choice to each patient’s optical system as well as their visual needs and desires.
Although it can be an intellectual challenge, matchmaking your patients in this way is incredibly gratifying when they are thrilled with their postoperative vision.
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Nandini Venkateswaran, MD, is a cataract, cornea, and refractive surgery specialist at the Massachusetts Eye and Ear Infirmary in Waltham, Mass. She is also a clinical instructor of ophthalmology at Harvard Medical School. She joined the
YO Info editorial board in 2020.