Rethinking Cataract Surgery Expectations: Is Total Spectacle Independence Possible?

Prior to cataract surgery, patients may wonder if total spectacle independence is possible. Now, with so many advancements in lens technologies, it might be worthwhile to reexamine that question. An undeniable truth in optics, known to ophthalmic scientists and surgeons alike, is that improvement in vision quantity invariably leads to declines in vision quality. Limitations of presbyopia-correcting intraocular lenses (IOLs) continue to pose a formidable challenge in our mission to empower patients to see well without glasses after cataract surgery.

The origins of presbyopia-correcting technology traces back to the work of pioneers like Dr. Kenneth J. Hoffer, who conceptualized the multifocal IOL in 1983.¹ The first implantation of a refractive multifocal (2-zone) IOL was performed by Dr. John L. Pearce in 1986. In 1997, the AMO Array IOL (Allergan) became the first commercially available lens in the US. Since then, numerous bifocal-multifocal designs of diffractive or refractive principles (or both) have been released, including those with low-power (intermediate) and high-power (near) adds, which were often combined via a mix-and-match approach to achieve a greater range of vision. A breakthrough came when the PanOptix (Alcon) trifocal IOL became available in 2019. This option simultaneously yielded great vision at distance, intermediate, and near. Beyond multifocal IOLs, extended depth-of-focus (EDOF) technology, which provided continuous vision from distance to “functional near,” entered the mainstream in the US with FDA approval of the Tecnis Symfony IOL (Johnson & Johnson) in 2016 and then the Vivity IOL (Alcon) in 2020, which became the first non-diffractive EDOF lens. Presbyopia treatment has advanced even within the monofocal IOL category over the past few years with the introduction of an “enhanced” monofocal IOL, the Eyhance (Johnson & Johnson), as well as the light-adjustable lens (Rx Sight), both of which provide better intermediate vision than a traditional monofocal IOL. In the near future, truly accommodating IOLs are expected to become the “holy grail” of presbyopia-correcting lenses.

All these advanced options beg the question: can patients expect more with regard to postoperative spectacle independence? Will total spectacle independence after IOL implantation become available to more patients as these premium options make up a larger slice of the market? How close to total spectacle independence can an individual patient currently achieve? As the market changes, surgeons must develop a strategy to discuss the potential for spectacle independence with patients who are scheduled to undergo cataract surgery, or other lens replacement procedures.

Current State of Spectacle Independence

Following a long period of stagnation, the adoption of presbyopia-correcting IOLs has risen significantly thanks to modern day IOLs that offer improved visual quality, decreased photic phenomena, and the opportunity to achieve greater spectacle independence than ever before. While setting realistic expectations remains a vital part of patient counseling, innovations in presbyopia-correcting technologies are moving the needle towards delivering total spectacle independence for our patients.

There are currently 3 popular approaches to maximizing spectacle independence with presbyopia-correcting IOLs: 

1. Bilateral EDOF IOL implantation with a micro-monovision approach (aim -0.25 to -0.75).
2. Bilateral multifocal IOL implantation (aim plano).
3. EDOF IOL implantation in the dominant eye and multifocal IOL in the nondominant eye with a mix-and-match approach (aim plano).

Bilateral EDOF IOL Implantation With Micro Monovision

The Tecnis Symfony extended depth-of-focus IOL provides a single elongated focal point utilizing a diffractive model with an echelette design and an achromatic surface to correct for chromatic aberrations and enhance contrast sensitivity. While EDOF IOLs do not offer as much near vision as multifocal IOLs, they often provide better quality distance vision with fewer dysphotopsias. A prospective study involving 15 sites in the US examined a total of 148 patients bilaterally implanted with the Symfony. At 6 months postoperative, 91.8%, 89.1%, and 46.9% of patients reported never using glasses or contacts in the past 7 days for distance, intermediate, and near, respectively.² Similar to other EDOF IOLs, it is often necessary to target slight myopia (-0.25 to -0.75) in the nondominant eye to achieve greater spectacle independence at near.

The AcrySof IQ Vivity (Alcon) is a nondiffractive EDOF IOL that utilizes X-Wave technology to extend the range of vision. The Vivity Registry Study is an ongoing large investigation spanning 8 countries, with more than 650 participants who received bilateral implants. At the 3-6 month time period, 87.7%, 77.8%, and 44.7% of participants reported never using glasses under bright lighting conditions in the past 7-days at far, arm’s length, and up close, respectively.³ In the mini monovision cohort (at least 1 eye with manifest refraction spherical equivalent [MRSE] ≤-0.5 diopters [D], and absolute difference in mean MRSE between the eyes ≥0.5 D), the spectacle independence improved to 83.6%, 80.7%, and 60%, respectively. 

While the bilateral EDOF approach may not offer as much spectacle independence as a trifocal or multifocal IOL, it can be a great option for patients who desire maximum visual quality at distance with fewer nighttime visual disturbances. 

Bilateral Trifocal/Multifocal IOL Implantation

By far, the method for achieving the greatest level of spectacle independence at all distances is with bilateral implantation of a trifocal or continuous range multifocal IOL.

In May 2021, a multifocal lens with continuous range of vision, the Tecnis Synergy IOL (Johnson & Johnson), was FDA approved. Available outside of the US since 2019, this hybrid model combines elements of the Tecnis multifocal (+4.00 add) and Symfony. A recently published prospective randomized trial demonstrated excellent spectacle independence in 137 patients across 15 US sites with bilateral Synergy implantation. At 6 months, 93.1% of patients reported no usage of spectacles overall.⁴ Smaller studies have also found encouraging results, including an investigation of 54 eyes in Portugal which reported only 3.7% required spectacle use for intermediate/near vision at 3 months.⁵ An ongoing trial continues to review the real-world outcomes of patients implanted with the Tecnis Synergy IOL followed for 12 months (ClinicalTrials.gov Identifier: NCT05090826).

Similarly, the AcrySof IQ and now Clareon PanOptix IOL (Alcon) offer a full range of vision including near, intermediate, and distance. A recently published a meta-analysis encompassing 13 global studies with 603 patients and showed that 9 out of 10 patients can expect to achieve total spectacle independence with bilateral PanOptix implantation (89.6% for near, 96.3% for intermediate, and 95.9% for distance).⁶  

Despite the high level of spectacle independence offered by both the Synergy and PanOptix, it remains critical to set realistic expectations by counseling patients on the possibility of nighttime visual disturbances as well as the need to use readers for fine print, especially under dim lighting conditions.

Mix-and-Match EDOF/Multifocal Approach

Implanting an EDOF IOL in the dominant eye and a trifocal/multifocal in the non-dominant eye allows one to take advantage of the favorable features of each IOL type. This mix-and-match approach has been shown to provide good spectacle independence, while theoretically reducing dysphotopsias. In a prospective study of 28 patients implanted with a Tecnis Symfony in the dominant eye and a diffractive bifocal Tecnis ZLBOO (+3.25 add) in the other, only 10.7% reported spectacle dependence at near at the 3 month timepoint, while 0 reported dependence at intermediate and far.⁸ Other combinations of lenses frequently employed via a mix-and-match approach include the Vivity and PanOptix, as well as the Symfony and Synergy. 

At the 2022 American Society of Cataract and Refractive Surgery (ASCRS) meeting in Washington, D.C., a presentation (by Dr Zhu) of 35 patients implanted with a PanOptix trifocal IOL and a Vivity EDOF IOL, showed that nearly 90% of these patients achieved total spectacle independence with a 97% reported patient satisfaction rate. In her clinical experience, patients appear to experience fewer dysphotopsias with similar levels of spectacle independence with the mix-and-match approach compared to bilateral PanOptix implantation.⁹ 

A Look at the Future

The most recent presbyopia-correcting IOLs have evolved in design beyond diffractive optics. The AcuFocus IC-8 Apthera IOL (Bausch + Lomb) is the latest presbyopia-correcting IOL to be approved by the FDA in July 2022. The IC-8 achieves an EDOF effect through the use of a small central aperture and is intended to be implanted in the nondominant eye (usually -0.75 aim) and a monofocal IOL in the dominant eye. In a multicenter retrospective case series of 126 eyes implanted with the IC-8 (monocularly) in Australia, 54% reported spectacle independence for reading and 91% for distance at final follow-up.¹⁰ The Lenstec ClearView 3 IOL, also FDA-approved in July 2022, is a refractive, rotationally asymmetric segmented multifocal design. In a prospective case series in the UK including 100 eyes bilaterally implanted with the ClearView, 88% of patients reported never wearing reading glasses at postoperative month 3, and 92% reported the same at month 12.¹¹ Perhaps the most highly anticipated presbyopia-correcting IOLs are those utilizing a novel accommodative design on the horizon, including the LensGen Juvene, which incorporates a fluid-filled curvature-changing lens within a capsule-filling base lens.¹²

As the famous aphorism of the law of the instrument notes, to those who walk around with only a hammer, everything appears to be a nail. Ultimately, selection among the wide array of IOLs must be done judiciously, in a personalized approach tailored to patient goals, lifestyle, and anatomy. This must be combined with a thorough preoperative exam to identify ocular comorbidities. It should be acknowledged that perfect replication of physiologic accommodation may not be possible. Additionally, an element of neuroadaptation is required for patients to adjust and achieve optimal outcomes post-operatively. Still, thanks to ongoing iterative design and innovation, more patients are achieving freedom from glasses today than ever before, and we will continue to expand our armamentarium of presbyopia-correcting technology to improve spectacle independence.