Advances already in place are making it easier for doctors to help patients get the most out of presbyopia correction options. From selecting the right lenses to managing postoperative refraction errors, all of the hot topics in presbyopia were covered during the Presbyopia IOL Forum at the recently held 26th European Society of Cataract & Refractive Surgeons Winter Meeting (ESCRS Winter Meeting 2022).
Enhanced chances for spectacle freedom?
Enhanced monofocal intraocular lenses (IOLs) could help reach 80% of the cataract surgery market by virtue of their design, which could help give more satisfaction to presbyopia patients, according to Prof. Dr. Gerd Auffarth (Germany).
He said this while citing that only 8% out of the total cataract surgeries are for presbyopia correcting IOL implants (ESCRS Clinical Survey 2020), 14% of which are toric lenses.
The design of monofocal plus IOLs incorporate a small increase of multifocality (or depth of field) which can minimize worsening quality of vision and night vision symptoms — two chief hurdles faced in presbyopia correcting IOL procedures.
These enhanced monofocals are able to maintain the reliable UCDVA (uncorrected distance visual acuity) and reduced rates of dysphotopsia compared to standard multifocal IOLs. “We could perhaps use the depth of focus for a larger landing zone for postoperative target refraction,” Dr. Auffarth explained.
Also, any improvement on the depth of focus to reach intermediate focus could also reduce spectacle dependence, but only on the near points, he added. Presbyopia correcting IOLs in patients are reported as the least satisfied with intermediate vision performance in the 2021 ESCRS Clinical Trends Survey.
He presented a comparison of several enhanced monofocals in the market including the TECNIS ICB00 Eyhance by Johnson & Johnson, BVI’s IsoPure and Rayner’s RayOne EMV (monovision).
Matching Presbyopia Needs with Better IOL Tech
As there are a wide range of advanced presbyopia correcting IOLs available, Prof. Dr. Burkhard Dick (Germany) said patient selection and understanding their needs are key to helping them find the best match with their ideal IOL.
Advanced presbyopia correcting IOLs are ideal for patients seeking spectacle independence and those performing near and immediate vision tasks, he said. “Newer technology is more forgiving and can be beneficial for patients with mild dry eye, few hard extrafoveal drusens, and those who are possible glaucoma suspects.”
Enhanced monofocal lenses are suitable for those who are active and would benefit from slight extended depth of focus for work on computers, tablets and cell phones, as well as in sports. However, not every patient is a candidate for diffractive technology (those with dry eye or other retinal diseases), he shared.
EDOF IOL patients would essentially be in the same cohort as those suited for multifocal IOLs and who are seeking spectacle independence for most activities, like golfing, skiing, diving and running. They would like to benefit from intermediate vision functions and are also risk averse to visual disturbances.
“You can choose patients with mild macular changes or with early glaucoma without obvious field loss, as these are not as significant a problem as for traditional multifocal IOLs,” he explained.
With hybrid multifocal IOLs, these patients have a stronger desire for spectacle freedom at all distances, and a strong need for near vision and may be willing to accept a compromise (of dysphotopsia) for best near visual function, Prof. Dick said.
Counseling Refractive Lens Exchange Patients
Refractive lens exchange (RLE) or replacement (RLR) is an elective procedure involving the removal of the transparent crystalline lens with IOL implants to correct ametropia and/or presbyopia. Besides describing the ideal and non-ideal patients for this procedure, Dr. Francesco Carones (Italy) offered his take on having clear communication, especially in selecting patients for this procedure.
Surgeons could use DLS as an opportunity to counsel patients on RLE. “The advanced diagnostic detection of DLS (dysfunctional lens syndrome) is very useful for staging the dysfunction and helping patients understand what is going on with their eyes,” Dr. Carones said.
“It is important to educate patients on all the vital information coming from their diagnostics. Emphasize that there are no perfect solutions, that there are different lenses … how do RLE and IOLs work … and it is important that a decision is reached,” he said, reminding doctors that they have a responsibility to give confident advice while fleshing out the options and contingencies to patients.
“We must have empathy, to build trust and a good relationship so that we can prevent or diffuse difficult situations like having picky patients, or if surgical complications occur. It is important to have the patient as a part of the team.”
Currently, visual acuity is no longer the only goal for patients’ satisfaction, as many European patients now have more active lifestyles, he said, adding that patients prefer “functional vision.”
New measures of visual function include factors such as spatial contrast-sensitivity, vision under low luminance, temporal sensitivity and motion perception, as well as visual processing speed.
Keys for Accurate Lens Power Selection
“Accurate lens power selection demands biometric data validation and proper IOL power calculation methods. But first, it’s mandatory to have a preoperative evaluation of all the associated pathologies — not only to assess the quality of the vision, but to achieve emmetropia,” Dr. Filomena Ribeiro (Portugal) said during her session.
Recognizing the rules to solve the corneal dioptric power is the first “golden key,” Dr. Ribeiro said. The cornea represents two-thirds of the total dioptric power and small changes can be very significant in IOL power calculations.
For good power data, several measurements of the cornea’s ocular surface should be taken — if possible, with more than one instrument.
Another key is to understand the mean of the different corneal dioptric power values. She said that it is important to compare measurements with the population average. Also, one must always do the spherical and toric calculations for every patient.
Current formula improvements are seeing better optical actual lens error corrections, improved estimates for ELP with more predictors, and increased computational powers for empirical adjustments.
Things have changed in the last five years. “We were very used to the third generation formulas (for IOL calculations), and they can still be used, but we need to be aware that you need to optimize your measurements, and optimize your lens with the optical biometry, so, it’s a lot more work in the pre-op formulations,” she explained.
“I think we should change to the new formulas as they are easier with these optimizations.”
Postoperative Refractive Errors
Lastly, in managing postoperative refractive error to maximize patient satisfaction, Dr. Rudy Nuijts, (Maastricht, Netherlands) said more than 40% of toric IOL patients still have more than 0.5 D of residual refractive astigmatism, based on randomized controlled trials and real-life databases.
He highlighted that accurate marking is very important to avoid misalignment of toric IOLs, while showing that digital marking systems tend to be more accurate and more comfortable for patients.
Dr. Nuijts also said that if residual refractive errors occur, surgeons should analyze which factors contributed to the unexpected outcomes— be it increased SIA (surgically-induced astigmatism), posterior astigmatism or any misalignment.
Editor’s Note: The 26th European Society of Cataract & Refractive Surgeons Winter Meeting (ESCRS Winter Meeting 2022)was held virtually from February 18-20, 2022. Reporting for this story took place during the event.