One-piece design provides additional benefit to an already successful implant

Dec 01, 2009

A new Tecnis intraocular lens harnesses the ease of implantation of a one-piece implant design and combines it with a glistening-free hydrophobic acrylic material for another next generation IOL.

Key Points

The overall goal

The goal of the evaluation was to assess implantation behaviour and performance of the ZCB00 lens and to optimize the A-constant. The web-based registry provided a platform to display their outcomes and preferences stemming from routine IOL usage, without the artificial constraints of inclusion and exclusion criteria that are a typical provision of a controlled clinical trial.

The ZCB00 represents the marriage between this proven acrylic technology and a novel one-piece lens with the so- called TriFix haptic design that affords IOL stability via three-point fixation. This design provides stability because it enables the lens to be constantly pressed outward and backward against the capsular bag. Another beneficial aspect of the new lens is ProTec 360° a full circular sharp edge of the optic that minimizes cell migration with an uninterrupted barrier edge and an uninterrupted haptic-optic junction.

IOL calculations

The web-based registry logged the results of 659 patients from sites in Germany, Belgium and Switzerland. The ratio of male to female patients was 44% to 56% respectively; and patients ranged in age from 39 to 90 with a mean age of 74.6 ± 8.5. Biometric data including keratometry, axial length, anterior chamber depth, biometry formula and target refraction were gathered and reported to ULIB for optimization of the A-constant. The ultimate goal of the project was to document the handling and visual outcomes of the new one-piece Tecnis IOL, but additional findings regarding biometry formula preferences added depth and perspective to their outcomes. The SRK/T biometry formula was used in 67% of the cataract procedures. The next most popular biometry formula was Haigis, which was used in 31% of the surgeries. The SRKII, HofferQ and Holladay biometry formulas were employed in 1.6%, 0.15% and 0.15% of cases respectively.

The Emerald AR Unfolder, which was designed specifically for this IOL, was the leading implantation device. It was used in 61.6% of the cases. It is not possible to implant this lens with forceps. Every surgeon described each of the implantations as smooth. No optics were damaged in any of the almost 700 cases and haptics remained damage-free in 99.6% of cases. Centration was achieved in 99.6% of cases and there were no instances of tilt reported in the entire group.

Postoperative results

My experience, as well as the collective reported evidence from the other participating surgeons, indicate that the one-piece Tecnis ZCB00 offers stable early and late postoperative refraction; ease of implantation and attainment of target refraction in the vast majority of cases.