OSN Europe: Is monovision with monofocal IOLs a viable alternative to multifocal IOLs?

POINT

Modest monovision provides untroubled vision, with occasional spectacle use

My personal preference is to use modest monovision with monofocal IOLs as an alternative to multifocal IOLs to reduce patient dependency on spectacles for near vision after cataract surgery.

Graham D. Barrett

Although higher levels of myopic defocus provide a greater level of spectacle independence, a target of –1.25 sphere is preferred. This level of anisometropia preserves stereoacuity and is less likely to be associated with a reduction in binocular contrast sensitivity. Furthermore, this provides patients with an extended range of clear vision from distance to near, although additional correction may occasionally be required for reading small print.

Although multifocal implants provide a great level of spectacle independence, this parameter is not the most important index for patient satisfaction and a successful outcome. I am sure many of my colleagues have also seen patients after multifocal IOL implantation, with unaided 20/20 vision and J1 at near, who are highly unsatisfied with their vision, even requiring lens exchange.

Attempting to explain to patients the impact of multifocal implants and screen for unsuitable patients is demanding and not always successful. With modest monovision, it is straight forward. If 20/30 or better unaided vision for distance is obtained in the first eye, the option of modest monovision can be easily demonstrated to patients with the addition of a 1.25 sphere in the trial frame with their recently operated eye.

Patients are not always able to comprehend the concept of reduced sensitivity as well as halos and scatter, which can be troublesome with multifocal lenses. In addition, modest monovision is less sensitive to issues such as minor levels of defocus and macular dysfunction, which may occur with the passage of time.

The most important reason for preferring modest monovision is that patients are highly satisfied with their outcome. This solution provides functional near vision, and the occasional use of spectacles for reading is not considered problematic, unlike the undesirable compromise in visual function inherent with multifocal IOLs.

Graham D. Barrett, MD, is Associate Professor at the Lions Eye Institute and Head of the Department of Ophthalmology, Sir Charles Gairdner Hospital, Nedlands, Western Australia. Disclosure: Barrett reports no relevant financial disclosures.

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COUNTER

With multifocal IOL advancements, monovision now a niche procedure

Multifocal IOL technology has markedly improved in the past few years. We can now rely on a wide range of options, in which no lens is better than the other, but there is always a lens that is better suited for a given patient. New optic designs have also reduced visual phenomena. In this new scenario, the role of monovision has diminished. It made a lot of sense in the past, when multifocal lenses had considerable drawbacks in terms of visual effects, loss of contrast, poor intermediate vision and decreased sharpness for far.

Francesco Carones

I still offer monovision as an option to a minority of patients, maybe about 5%, and they do not consider complete spectacle independence as an absolute priority. They do not mind an addition for reading small print and definitely prefer the inconvenience of wearing spectacles for night driving to the disturbance of halos and glare. The advantage of monovision is that it is fully and immediately reversible with spectacle correction. No multifocal lens gives you this option.

I use multifocal IOLs in 65% of my cases. They can fulfill the needs of most people and require less adaptation. Patient selection is no longer a concern in the sense of having to deal with an unpredictable percentage of unhappy people. It is rather choosing the right lens for each patient individually. There is the Symfony (Abbott Medical Optics) for patients who do not have high expectations but want fairly good vision at all distances, trifocals for those who want very good intermediate vision, and several other options. Undoubtedly, multifocals give better stereoscopic vision and spectacle independence. The only drawback that remains is night vision, in which they still create a few problems.

Francesco Carones, MD, is an OSN Europe Edition Board member and Medical Director of Centro Oftalmico Chirurgico Carones, Milan, Italy. Disclosure: Carones reports he is a consultant to Alcon and receives travel support from Abbott Medical Optics.

Click here to read the full Point/Counter published in Ocular Surgery News Europe Edition, July/August 2015.