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Recent FDA approval expands multifocal IOL choices
New low-add powers offer enhanced vision at intermediate distances, with improved night vision symptoms.
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With the recent FDA approval of two new Abbott Medical Optics Tecnis multifocal IOL models with lower add powers, we now have a family of multifocal IOLs that gives surgeons more choices to achieve spectacle independence and a full range of high-quality near, intermediate and distance vision in patients who have varying visual needs.
I was a clinical investigator in the FDA investigational device exemption trial, which was conducted at 18 sites across the country. This was a prospective, age-matched, open-label study in which all subjects were bilaterally implanted with either the control Tecnis monofocal one-piece IOL (ZCB00) or one of two Tecnis multifocal IOLs with lower add powers, +3.25 (ZLB00) or +2.75 (ZKB00). The low-add multifocals are identical to the Tecnis multifocal IOL +4.0 in all aspects except add power, which is achieved by reducing the number of diffracting rings and increasing the area of each ring. Approximately 150 subjects were enrolled in each lens group; assignment was determined by the patient’s choice.
The mean age in each of the three groups was approximately 68 years. The primary study endpoint was distance corrected near visual acuity (DCNVA) measured at 40 cm. At 6 months, monocular DCNVA was 20/40 in +2.75 eyes, 20/32 in +3.25 eyes and 20/80 in control eyes; binocular DCNVA was 20/32, 20/25 and 20/63, respectively. The differences in DCNVA were statistically significant. There were no differences among the three lens models in monocular and binocular uncorrected and best corrected distance visual acuity.
Patient satisfaction was high, with more than 80% of patients able to function comfortably without glasses at 6 months at distance, intermediate and near for both multifocal groups. Rates of spectacle independence were likewise high, with more than 96% of patients in the +3.25 group and 98% of patients in the +2.75 group able to function comfortably without glasses at intermediate and far distances. Three-quarters of the +3.25 group and 61% of the +2.75 group reported that they never wore glasses.
Daniel H. Chang
The +4.0 is a great lens and one that I have implanted often. Occasionally a patient has concerns about this lens, and they are usually related to intermediate vision or halos at night. The new low-add options address both of these issues.
Intermediate vision
By moving the theoretical reading distance out further, the two new add powers provide enhanced intermediate vision, as can be seen in the defocus curves from the FDA investigational device exemption study (Figure 1).
Source: AMO
Now we can ask patients where they prefer their best near vision based on their lifestyle needs. When I evaluate my patients, I ask them how much time they spend driving, working on the computer, reading and performing various activities. Now I can match the distance of their best near/intermediate vision to the range that they want with the high-quality optics of any of the three Tecnis multifocal IOLs (Table).
Night vision symptoms
When patients complain of halos with the +4.0, they typically note the size of the halos as a primary concern. Because halos are the result of the defocused near image on the retina, halo size is related to add power. Lower add powers create smaller halos, which appear to be less distracting and less likely to block the view of surrounding objects.
In the FDA clinical trial, the degree of difficulty reported with night vision, glare/flare and halos for the low-add lenses was less than half that reported historically for the +4.0. With the +2.75, the reported degree of difficulty with night vision was even lower than with the Tecnis one-piece monofocal control. What I found was that while patients noted halos, few were bothered by them; if they were, the effects mostly abated in weeks rather than months.
Putting it in practice
In the FDA trial, all patients had bilateral implantation of the same IOL model, but I am excited about the opportunity to use different add powers in the same patient to maximize satisfaction and spectacle independence. This way, I can choose what I expect will be the best add power for the first eye, and I have the option to tailor a different add power selection for the second eye to enhance near or intermediate vision, based on the patient’s desires.
With the whole Tecnis multifocal family of IOLs now in my armamentarium, I have more confidence that I can provide my patients with a complete range of quality distance, intermediate and near vision. With an improved night vision symptom profile, I can make more patients happy with the range and quality of their vision.
For more information:
Daniel H. Chang, MD, can be reached at Empire Eye and Laser Center, 4101 Empire Drive, Suite 120, Bakersfield, CA 93309; email: dchang@empireeyeandlaser.com.Disclosure: Chang reports he is a consultant to AMO.