Premium IOLs offer new visual possibilities for patients and a range of novel options for the clinician. As a surgeon practicing in Australia, I sometimes have access to new IOLs before they become available in the United States.

In this article, I provide a look at how I use premium IOLs, including options that may soon be available in the United States. Hopefully this might give you a head start on how to use these premium IOLs. I cover toric IOLs and presbyopia-correcting IOLs (PC-IOLs). For PC-IOLs, I discuss small-aperture and multifocal IOLs. The three categories of multifocal IOLs I address include bifocal, trifocal and extended depth of focus (EDOF).

DEFINING OUR TERMS

Although there has been some debate surrounding terminology, premium IOL is a term commonly used to describe an IOL that delivers something over and above what a standard monofocal IOL would deliver at the time of cataract surgery or refractive lens exchange. In general, this term describes astigmatism-correcting or PC-IOLs.

Different reimbursement models around the world have driven the uptake of this term, which implies better results for a higher price.

In my practice, I offer multiple options for my patients undergoing lens surgery. My strategy tends to be to mention all options but target discussion toward appropriate options for the individual patient. I do most of my own counseling and have a high toric usage rate and a lower PC-IOL usage rate, likely a result of a significant number of patients in my practice having concurrent corneal disease. I frequently consider monovision (usually of moderate degree) for appropriate patients.

TORIC IOLS

In my practice, I consider toric IOLs as standard rather than premium. This evolution has resulted from a combination of better diagnostics, formulae, accuracy and measurement of the required axis and IOL options (in terms of both power availability and rotational stability) as well as availability of different toric IOL options.

Many surgeons in Australia, including myself, perform a toric calculation on every patient undergoing cataract surgery and will implant as recommended by an appropriate calculator that takes into account posterior corneal astigmatism, unless a toric IOL is contraindicated for a particular reason. Specifically, I usually target the lowest magnitude of residual astigmatism irrespective of the final axis compared with the pre-existing axis of the patient’s astigmatism.

The overall rate of utilization of toric IOLs in Australia is almost 32% according to Infoview Data Analytics. During the past 2 years in my practice, I used a toric IOL in 70% of my private cataract surgery cases; I used a low-power toric (Alcon SA6AT2 or Johnson & Johnson Vision ZCT100) in 33% of my private cataract surgeries. It is the ability to precisely treat small amounts of astigmatism that makes the difference, rather than any other qualities of the IOLs. Low levels of astigmatism are extremely common, and it is well-known that residual (untreated) astigmatism is one of the leading causes of poor satisfaction or outcomes following cataract surgery. These low-power toric IOLs are not currently available in the United States; when they win FDA approval, U.S. surgeons may see dramatic improvements in their outcomes.

While I take a lot of time counseling patients and explain many IOL options, I do not routinely provide them with an option to receive a toric IOL or not. This is because I do not see any advantage to not correcting astigmatism, and there is usually no financial incentive or disincentive. For insured patients, my reimbursement is the same whether or not a toric IOL is used and their out-of-pocket cost is unaffected (see “Cataract surgery Down Under”).

I avoid use of a toric IOL in certain situations such as irregular astigmatism or astigmatism that is not reproducible in magnitude or direction across primary, secondary and tertiary measurements. I also avoid toric IOLs for patients who use and plan to continue to use rigid gas-permeable contact lenses and for certain transplant patients in whom the astigmatism might be unstable or for whom future surgeries may be unpredictable.

In those situations, I explain to patients why I am not recommending astigmatism correction for them. Instead, I might consider a non-toric IOL or another option such as a small-aperture IOL or a piggyback toric IOL.

PC-IOLS

While I view astigmatism correction essential and routine, I consider presbyopia correction to be optional. Patient decisions are based on a number of factors and tend to be heavily influenced by surgeon recommendations as well as the individual patient’s motivation for spectacle independence as well as willingness to tolerate side effects.

This category in general is becoming much more important to patients, so I expect my utilization to significantly increase over the next few years as reproducibility and available options continue to improve and as patient expectations continue to rise.

SMALL-APERTURE IOLS

In recent years, we have seen the new category of small-aperture IOLs enter the premium IOL space. Small-aperture technology could be considered and is often utilized as a PC-IOL but also benefits patients with irregular corneal astigmatism or patients with significant degrees of higher-order aberrations. These patients have previously been excluded from premium IOL use, so I find this category quite interesting and useful.

The IOL available in Australia in this space (since 2016) is the IC-8 (AcuFocus; it’s currently undergoing FDA clinical trials in the United States). Morcher also markets the XtraFocus, which, while not technically an IOL, also relies on small-aperture optics to improve outcomes.

Just like a pinhole, a small-aperture IOL works by incorporating a central mask to block peripheral defocused light rays from disrupting the image that is focused on the retina. The IC-8 IOL has a central 1.36-mm aperture that flattens the defocus curve, providing continuous EDOF over a functional range of about 2.5 D.

When combined with a small amount of myopic target and implanted monocularly in the non-dominant eye, this IOL can provide patients with an enhanced monovision. The refractive target for the near eye can be tailored according to the patient’s needs, but between -0.75 D and -1.0 D is my standard. I call this enhanced monovision, because, in my experience, the patients achieve an equivalent functional range of vision with less anisometropia compared with monovision patients with a -1.25 D aim with monofocal IOLs.

I recently completed a trial comparing moderate monovision with monofocal IOLs to mini monovision with the IC-8 small aperture IOL. In this prospective, post-market, randomized single-site study, we measured the primary outcomes of visual acuity at all distances and patient satisfaction between the IC-8 group and the monofocal group for 40 patients. These data are currently being prepared for publication.

In short, we found that mini monovision with IC-8 provided the same range of vision as moderate monovision with monofocal IOLs with less anisometropia. Patients in both groups reported high satisfaction with vision at all distances and in all lighting conditions.

IC-8 also benefits patients who are not suitable for other technologies due to irregular astigmatism or corneal aberrations. I find this IOL particularly useful for post-refractive cases. Also, it has shown to be useful and forgiving for patients with history of radial keratotomies, keratoconus and other corneal diseases.

MULTIFOCAL IOLS

Multifocal IOLs should reduce spectacle dependence at distance, intermediate and near tasks. Multifocal IOLs so far have been either refractive or diffractive and incorporate a number of different focal points. The three categories of multifocal IOLs include bifocal, trifocal and EDOF.

Bifocal multifocal IOLs typically incorporate far and near foci. These have been superseded and are not commonly used in Australia. Trifocal IOLs have an additional focal point for intermediate range, making them an attractive option for patients. In my opinion, trifocal IOLs are the most predictable and reliable means of presbyopia correction.

When considering trifocal IOLs, it is essential to choose the right patients in terms of ocular health, visual requirements, lifestyle, mindset and motivation for spectacle independence. In many cases, following ocular examination or measurements I caution against trifocal IOLs due to an increased risk of side effects or dissatisfaction, and I do not use them if the patient lacks motivation to be free of glasses.

Others may be unsuitable candidates for trifocal IOLs when they have ocular comorbidities such as dry eye, subclinical keratoconus, corneal scars or macular disease or an inappropriate higher-order aberration profile. Even to these patients, however, I mention the existence of trifocal IOLs so that they understand why they are not suitable.

For the right candidate, I consider trifocal IOLs to deliver the best chance of overall spectacle independence. I explain the likelihood of some degree of dysphotopsia (glare and halos) as the trade-off and also explain that explantation is possible but best avoided.

In Australia, we have multiple trifocal options. I prefer hydrophobic IOLs and have primarily used PanOptix (Alcon), although we have other hydrophobic options available. Hydrophilic IOLs provide excellent outcomes as well although may not be as commonly used in Australia. Commonly used IOLs include those from PhysIOL, which come in hydrophobic and hydrophilic, Zeiss (hydrophilic) and Alcon (PanOptix hydrophilic).

Particularly when using trifocal IOLs, it is extremely important to aim for as close to emmetropia as possible. I aim to correct all astigmatism and perform refractive enhancements at 3 to 4 months postoperatively when necessary.

EDOF IOLs have a single but elongated focal point between far and intermediate. My understanding is that these are more popular in the United States than in Australia. This may be due to more trifocal options here. I do not often recommend EDOF because of the reduced near vision compared to trifocals and the still-present risk of glare and halos.

NEW TECHNOLOGIES

Several exciting new technologies are just becoming available in Australia. Johnson & Johnson Vision recently released TECNIS Eyhance and Synergy, and I believe Alcon has Vivity becoming available in 2020.

Eyhance is technically a monofocal IOL but is said to deliver enhanced intermediate vision. This intermediate vision is provided by a continuous change in power of the anterior IOL surface from the center to the periphery of the optic. So far, results of a prospective, multicenter, randomized clinical study indicate that distance visual acuity is comparable to monofocal IOLs but that intermediate vision is improved, with absence of photic phenomena that might result from a diffractive IOL and with the advantage of being independent of pupil size, according to J&J Vision.

While this IOL has been available in Australia since 2019, absence as yet of an available toric version has made it difficult to find appropriate patients for bilateral implantation. I look forward to trying this when a toric version becomes available in 2020. IOLs of this category could lead to presbyopia correction, becoming more of a standard rather than an optional outcome and could replace standard monofocal IOLs in my practice.

Likewise, Synergy does not yet have a toric form. According to the company, this technology combines EDOF and trifocal technology to create a smoother curve with more of a continuous range of vision than the traditional three peaks of a trifocal defocus curve. This makes sense for the dynamic visual requirements of most patients today. Presumably there will still be some trade-off in terms of optic phenomena.

Over the next 6 months, we expect to have access to the Alcon Vivity, a non-diffractive extended vision IOL. This IOL improves near and intermediate vision without affecting distance vision and maintains a monofocal-like side effect profile, according to research presented at 2019 ESCRS by Schwiegerling et al and Poyales et al.

AWAITING THE HOLY GRAIL

Although I do not use accommodative IOLs yet, I look forward to IOLs that provide a high amplitude of accommodation and that are repeatably adjustable in terms of power, toricity and higher-order aberrations. This is the Holy Grail for cataract surgery.

We can then provide our patients the ability to adjust these features as the eye changes, ages or develops disease and as the patient’s circumstances or environment change. OM

About the Author

Jacqueline Beltz, FRANZCO is a cataract, refractive and corneal surgeon in private practice in Melbourne, Australia. She is also program director for Ophthalmology Training for Victoria, Australia.

Financial disclosures: Dr. Beltz is a consultant for Alcon and serves on AcuFocus’s advisory board.