Eyeworld

EW CATARACT 30 October 2015 by Daniel H. Chang, MD similar. In fact, the greatest percent- age of patients reporting severe diffi- culty with night vision (4.1%) was in the monofocal control group. To me, the higher rate of sat- isfaction—even at night—with the multifocal lenses represents a para- digm shift in the treatment of pres- byopia. Historically, many surgeons have been reluctant to implant a lens that might cause night vision problems—and rightly so, given that primum non nocere (first, do no harm) is a basic principle of our practice of medicine. However, we must remember that presbyopia itself is a significant problem. Instead of making the choice for our patients, we should let them decide if they want to live with presbyopia or some possible night vision symptoms. As the same contrast sensitivity and low-light visual acuity for all three. Satisfaction and night vision With the lower add power designs, patient satisfaction with vision without glasses was high. Overall, 97% of patients with the ZKB00 (+2.75) and 93% of patients with the ZLB00 (+3.25) were completely or mostly satisfied with their vision without glasses, compared to 86% of those with the monofocal lens. Even at night, 89% of ZKB00 and 87% of ZLB00 patients were completely or mostly satisfied, compared to only 84% of those with the monofocal lens. These high levels of patient satisfaction are supported by the findings that difficulty with night vision between the low-add multifo- cals and the monofocal control was es among the three lens models in monocular and binocular uncorrect- ed and best corrected distance visual acuity. Rates of spectacle independence were high, with more than 96% of patients in the ZLB00 (+3.25) group and 98% of patients in the ZKB00 (+2.75) group able to function com- fortably without glasses at interme- diate and far distances. Three-quar- ters of the +3.25 group and 61% of the +2.75 group reported that they never wore glasses at any distance. More than add power Although we describe these lenses by their add power, add power alone is not sufficient to determine per- formance of a multifocal IOL. Light distribution, pupil dependence, and quality of vision also contribute to lens performance and patient satis- faction. Like the ZMB00 (+4.0), the new low-add Tecnis Multifocal IOLs have a full diffractive profile on the pos- terior surface of the optic. The relief height of the diffractive rings is the same across all three models, result- ing in an equal light distribution to distance and near, regardless of pupil size or add power. The optimization of chromatic and spherical aberra- tion, which is important for quality of vision, is also the same across all add powers. The only thing that varies among the three models is the focal point distance, which is con- trolled by the number and spacing of the diffractive rings (Table 1). One can therefore expect patients to have High patient satisfaction with new options for presbyopia correction may contribute to a paradigm shift in refractive cataract surgery, physician says S afety and efficacy of two new low-add multifocal IOLs was recently studied in a prospective, multi- center, evaluator-masked clinical trial. The study, in which I participated as an investigator, compared the +2.75 D (ZKB00) and +3.25 D (ZLB00) Tecnis Multifocal IOLs (Abbott Medical Optics, Abbott Park, Ill.) to the Tecnis 1-piece monofocal IOL (ZCB00). It was an open-label study, so patients chose bilateral implantation of one of the two Tecnis Multifocal IOLs or the monofocal control. Approximately 150 subjects were enrolled in each group. Six- month follow-up was available on 441 subjects, or 99.1% of those enrolled. The primary study endpoint was distance-corrected near visual acuity (DCNVA), measured at 40 cm. At 6 months, monocular DCNVA was 20/40 in ZKB00 (+2.75) eyes, 20/32 in ZLB00 (+3.25) eyes, and 20/80 in ZCB00 (control) eyes; binocu- lar DCNVA was 20/32, 20/25, and 20/63, respectively. The differences in DCNVA were highly statistically significant. There were no differenc- Full diffractive low-add multifocal IOLs expand options Model # of rings Add power (IOL plane) Add power (spectacle plane) Theoretical reading distance ZKB00 15 +2.75 D +2.01 D 50 cm/20 in ZLB00 18 +3.25 D +2.37 D 42 cm/17 in ZMB00 22 +4.00 D +3.00 D 33 cm/13 in " Instead of making the choice for our patients, we should let them decide if they want to live with presbyopia or some possible night vision symptoms. As risks and benefits shift, so should the standards of our clinical practice. " Table 1: Expanded family of Tecnis Multifocal IOLs

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