BLOG: Consider lifestyle, ocular health and demands when choosing an extended focus IOL
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Last month, we started a conversation about extended focus IOLs and what makes a patient a good or bad candidate. Looking beyond the patient’s ocular health, one should also consider their profession, personality and hobbies.
All of these lenses will cause some level of contrast sensitivity reduction and are likely not ideal for pilots, truck drivers, military and security personnel, and artists. Nighttime rings, star bursting and other aberrations are often a greater issue for this subset of patients and are a real risk in almost all extended focus (EF) IOLs due to lens design (the Vivity lens by Alcon somewhat excepting; see images).
While there are more EF IOL designs on the market every year, we will compare three commonly used lenses: Tecnis Synergy by Johnson & Johnson and AcrySof IQ Vivity and AcrySof IQ PanOptix, both by Alcon. These lenses are used to highlight different EF IOL designs and the associated pros and cons.
Please understand that our statements are generalized, and these lenses can behave differently for individual patients (both better or worse than described) based on many factors, some of which are outside both the surgeon’s and manufacturer’s hands, including patient neuroadaptability.
Extended depth of focus IOLs
Many optometrists consider Synergy and Vivity lenses extended depth of focus (EDOF) IOLs, but most lenses are a hybrid of multifocal diffractive, multifocal refractive and extended depth of focus designs. A purely EDOF lens would create a single, elongated focal point (think spherical aberration and the pinhole effect), while a trifocal IOL would split light to focus at three loci
Source: Kerri Norris, OD, FAAO
EDOF lenses offer the patient a continuum of vision from distance to near, although not all distances are created equal; they tend to be stronger at distant and intermediate ranges but weaker at near. We tell patients who choose an EDOF IOL that they will have greater need for postoperative readers than with a trifocal design, but they may enjoy better quality distance and intermediate vision and suffer fewer dysphotopsias than with pure multifocal IOLs. For this reason, these lens designs can be a good fit for more active, outdoorsy patients. Thinking back to our balancing act between quality of vision, depth of field and photopic phenomenon, EDOF lenses maximize depth of field and reduce dysphotopsias at the possible detriment of image quality.
Good options come with compromise
One might consider “mini-monovision” with EDOF IOLs by pushing a slightly myopic target in the nondominant eye for better near vision, but we all know the compromise to distance vision and worsening of aberrations one must be willing to take on. Mixing and matching EF IOLs is another option, again with its own risks and drawbacks.
Vivity is an EF IOL lens with no diffractive rings; therefore, it has monofocal IOL tendencies regarding glare/halos (it generally doesn’t have them except the low risk for dysphotopsia that any IOL has from the lens edge). It also has less loss of contrast sensitivity and is the most tolerant of mild retinal disease, such as subtle epiretinal membrane, mild and well controlled glaucoma and mild AMD, as well as mild corneal conditions like prior LASIK or subtle epithelial basement membrane disease. (Of course, many of these conditions have the possibility of progression, and patients should be educated on the risks. But in most cases, ultimately the choice is theirs.)
Source: Kerri Norris, OD, FAAO
The compromise here is Vivity offers the least near vision, and patients who select this lens should expect more postoperative near vision correction than any other EF lens. During patient education, we have been known to describe this as a distance and intermediate/computer vision lens. Any nearer vision experienced is just the cherry on top and should not be expected by the patient.
An IOL like the PanOptix is a truer multifocal/trifocal lens focusing at the three different distances but is weaker at ranges “in between” and may have a reduction in vision quality at all distances. This lens design has the highest risk for halos and star bursting of all EF IOL designs; however, PanOptix may be the best option for those demanding the strongest near vision. This is usually the lens we recommend for patients with close-up and detailed hobbies and those with a closer reading distance.
Find the best fit for the patient
With seemingly newer and better lens designs every year that are more tolerant of subtle deviations, we may find ourselves offering an EF IOL for a motivated patient who may not have been a candidate in the past. And while every lens has some inherent compromise, the trick is finding the best fit for the patient in your chair.
Greater range of vision means less crispness at any distance (PanOptix). Greater range often also means worse nighttime aberrations (IOLs with rings in the design, such as PanOptix and Synergy). Better distance vision means worse near vision (Vivity), and better night vision and fewer/no rings means worse near vision (Vivity). It is unlikely there will ever be a one-size-fits-all approach. Also remember that for any specialty lens, one needs to check that patients with higher prescriptions and astigmatism are in range of lens availability.
A good provider considers the ocular health, ocular demands and lifestyle of the patient in front of them and, as in all aspects of health care, proper patient education and patient selection promote success.
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