BLOG: Post-market studies demonstrate good stability of new toric IOL
Click Here to Manage Email Alerts
The Tecnis toric II, or the ZCU, from Johnson & Johnson Vision, is a new toric IOL.
It has the same optic as its predecessor, the Tecnis toric; only the haptics have been modified. They are squared and frosted to provide greater friction within the capsular bag, thus potentially improving rotational stability of the IOL.
Source: George O. Waring IV, MD
In a proof-of-concept study, this modified design did improve stability. At 1 week, the mean absolute rotation for the new haptic design was 0.71° ± 0.69° compared with 2.24° ± 3.21° for the original haptic design. The lens was approved by the FDA in December 2019, and I had the distinction of implanting the first commercial ZCU lenses in the world shortly after that. My experience with the lens since then has been very positive.
Post-approval, two prospective, multicenter open-label studies were conducted to evaluate the real-world performance of the IOL. One of these studies evaluated surgeons’ subjective satisfaction with the lens 3 months after implantation, while the other was an objective assessment of rotational stability, distance visual acuity and residual refractive cylinder.
In the subjective study, surgeons at eight sites who implanted 86 of the new toric lenses were asked to rate their satisfaction at 3 months. Nearly all (96.6%) of the surgeons reported being extremely or quite a bit confident in their ability to control the lens position, and 100% were satisfied to very satisfied with the overall clinical outcomes, rotational stability and uncorrected vision at 3 months.
In the objective study, ZCU IOLs were implanted in 200 eyes at six clinical sites. Image analysis software was used to measure any change in lens position from the conclusion of surgery to 1 week postoperatively (3-month data will be available when the study is completed). The images were analyzed by two independent, masked analysts. One week after surgery, the mean absolute rotation was 0.77° ± 0.65°, and the primary outcome measure of 5° or less of axis misalignment was met in 100% of the eyes. In fact, all eyes had 2° or less of axis misalignment.
Mean monocular uncorrected distance visual acuity was 0.04 logMAR, or 20/22 Snellen, and the mean manifest refractive spherical equivalent was –0.23 D ± 0.31 D. Residual cylinder was minimal. The mean preoperative keratometric cylinder of 1.78 D was reduced to a mean refractive cylinder of 0.23 D postoperatively.
These results are similar to what I am seeing in my own patients, as well. It is very encouraging that a superb optical platform is now even more rotationally stable. As with any other toric IOL, successful implantation of the Tecnis toric II requires meticulous biometry and preoperative measurement of the astigmatism axis and power. For best results, surgeons should take both posterior corneal astigmatism and surgically induced astigmatism into account.
Reference:
Waring GO, et al. Subjective and objective assessments of a toric intraocular lens with modified haptics. Presented at: American Academy of Ophthalmology annual meeting; Nov. 13-15, 2020 (virtual meeting).
Collapse