For patients seeking spectacle independence after cataract surgery or refractive lens exchange, implantation of a trifocal IOL is a better option than a lens with a bifocal optic or an extended depth of focus/extended range of vision design, according to Damien Gatinel, MD.
Whether using a bifocal or trifocal IOL, however, there are certain issues surgeons should consider in order to optimize outcomes and the likelihood of achieving satisfied patients, said Nick Mamalis, MD.
The case for trifocals
Reviewing the attributes of the different multifocal IOLs, Dr. Gatinel explained that relative to bifocal and extended depth of focus/extended range of vision designs, trifocal IOLs provide a more continuous range of uncorrected vision.
Furthermore, available evidence indicates trifocal IOLs deliver their benefit without increasing the risk of unwanted visual phenomenon.
“A bifocal IOL can provide good uncorrected vision at far and at near distances that are in the range of 30 to 45 cm, but they do not give good uncorrected vision for intermediate vision, which is important today for people who are working at a desktop computer, using a laptop, or reading a tablet,” explained Dr. Gatinel, assistant professor of ophthalmology, and head, anterior segment and refractive surgery department, Rothschild Ophthalmology Foundation, Paris.
Even lowering the add power of a bifocal IOL does not result in good intermediate vision because a “confusion focus” remains between the near and distance foci, he noted.
“Extended depth of focus and extended range of vision IOLs afford better intermediate vision than a bifocal IOL,” Dr. Gatinel said. “With these newer technologies, however, patients may still need to wear glasses for some near vision tasks.”
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Dr. Gatinel was involved in the design of the first trifocal IOL that became commercially available (FineVision, PhysIOL) in Europe in March 2010.
“The idea for this implant was born in my mind when I realized patients who were implanted with a bifocal IOL would thank me for their ability to read and drive without glasses, but they noted they still needed glasses with a low add for working at the computer,” he said.