Formula for achieving successful multifocal IOL outcomes
Because accurate correction of refractive error is key for good visual outcomes with multifocal diffractive bifocal and trifocal IOLs, Dr. Rocha said she uses intraoperative aberrometry to check IOL power and toric IOL alignment.
In order to reduce astigmatism, intraoperative correction with limbal relaxing incisions is planned in some cases. Depending on the amount of pre-existing astigmatism, some patients may be told they will need a combined-staged procedure with postoperative laser vision correction.
Functionality of IOLs
Understanding the functional outcomes associated with the different multifocal IOLs is also critical so the technology can be matched to the patient’s visual needs. However, surgeons should understand that information obtained from optical bench testing may not translate to the real-life situation.
“Studies using a single wavelength (green light) at one spatial frequency are not necessarily achieved in vivo,” Dr. Rocha said. “Ideally, IOLs should also be analyzed under white light and multiple spatial frequencies.”
Dr. Rocha noted that extended-depth-of-focus (EDOF) IOLs (Tecnis Symfony/Symfony Toric, Abbott Medical Optics) represent a new category of presbyopia-correcting IOLs available in the United States. This technology improves intermediate visual performance and near vision to a lesser extent without comprising distance vision.
The EDOF technology has the benefit of causing less glare and halos and less loss of contrast, especially compared to the first generation diffractive multifocal IOLs.
Looking ahead, Dr. Rocha said increased use of in vivo simulation, allowing patients to experience multifocality and compare different IOL designs, will become an important and useful component of the preoperative evaluation.
“This type of simulation is emerging in adaptive optics technologies that are friendly for use in the clinical situation,” Dr. Rocha said. “It should lead to increased confidence for patients and surgeons when choosing an IOL. It might also increase the number of multifocal IOL procedures performed along with overall patient satisfaction.”