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Customize IOL choice to patient’s lifestyle
A broad range of multifocal IOLs can provide an ideal near point for today’s active, tech-savvy patients.
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At Dell Laser Consultants, we believe so strongly in the unique opportunity that cataract surgery patients have to choose how they want to see for the rest of their lives that premium IOLs are the default in our practice. A small percentage of patients, about 5%, convert to a standard monofocal lens if they are not interested in a presbyopia-correcting or toric lens.
The choices for presbyopic correction are varied and complex. Rather than present a confusing menu of choices to the patient, we focus on determining through the history and a questionnaire what the patient’s visual needs are and recommend a solution that will provide the best vision for that patient’s occupation, hobbies and personality.
I am also extremely diligent about looking for conditions that would make a multifocal IOL a poor choice. We rely on advanced optical imaging, endothelial cell counts and multiple keratometry measures during the screening process to help identify anything on the optical axis that might affect the quality of light reaching the retina, such as persistent ocular surface disease, corneal dystrophies or degeneration, or macular issues that decrease contrast sensitivity. In such cases, I would recommend accommodating IOLs instead of multifocals.
Multifocal IOL selection
The add power determines the position of the near focus peak, which corresponds well with the theoretical reading distance.
Image: Cunningham DN
The Austin, Texas, market where I practice is an affluent, young, tech-savvy area where people are into fitness and rely heavily on their laptops, tablets and smart phones.
This has been a bit of a problem in prescribing multifocal IOLs, because the biggest deficit for these lenses has been at the intermediate distance. In the past, we often solved this by combining a Tecnis Multifocal (AMO) in the dominant eye with a Crystalens (Bausch + Lomb) in the nondominant eye. However, the predictability of the refractive target and the range of defocus one achieves with the accommodating IOL is not quite as good as it is with multifocal IOLs.
With the introduction of +2.75 D and +3.25 D add powers to the original +4.00 D Tecnis Multifocal, we now have a broader range of add powers that makes the decision process and patient conversation much easier. This is because multifocal IOLs are extremely predictable. They have two well-defined sweet spots where the vision will be clearest. The distance sweet spot is the same for all the lenses on the Tecnis platform; it is only the near point that varies.
I tell patients that an object viewed at a distance in between the two sweet spots will be significantly clearer than with a standard IOL, but not as clear as if it were in the sweet spot. With more add powers, we can more easily select the sweet-spot distance that best suits the patient.
I like to think of +2.75 D, +3.25 D and +4.00 D as low, mid and high adds, respectively. The low add is computer distance. The mid is a comfortable reading distance for many. The high is a little bit closer than most men would like, but a good near point for shorter people. Height is absolutely relevant. A 5’2” woman is going to hold her phone closer to her face than a 6’2” man, simply by virtue of arm length.
At press time, Alcon announced the FDA approval of its AcrySof IQ ReStor +2.5 D IOL. This would add another option for a low add.
A new mix-and-match paradigm
With the new range of options that we have now, we tend to offer the typical patient – someone who reads, drives and uses a computer and wants equally good vision at all those distances – a higher add (+3.25 D or +4.00 D) in the nondominant eye and the low add (+2.75 D) in the dominant eye. An avid reader might need bilateral high adds; someone who is always on his phone or computer might do better with bilateral low adds.
When multifocal IOLs were first introduced, many thought it was necessary for the two focal points to be far enough apart for the brain to keep them separate. We were somewhat concerned that low add multifocal IOLs, with the focal points closer together, might create visual confusion. However, that has not been the case in international experience with other lenses or with the clinical trials or our early experience with the Tecnis Multifocal low add lenses.
It is exciting to have a multifocal IOL that gives us the ability to provide highly predictable intermediate vision. The low-add multifocal IOLs expand our ability not only to talk to patients about specific near vision points but also to be far more confident that we can hit the refractive target at those points.