Hydrophobic acrylic lens shows promising results

Key Points

Chicago-A hydrophobic acrylic one-piece IOL (Tecnis 1-Piece, Advanced Medical Optics) provides excellent visual outcomes, refractive stability, and safety, according to Donald R. Nixon, MD, who presented his findings at the annual meeting of the American Society of Cataract and Refractive Surgery.

The main outcomes examined were visual acuity, occurrence of optical/visual symptoms such as halos and glare, incidence of postoperative complications, and adverse effects.

Dr. Nixon followed 20 patients in his practice, Trimed Eye Center, Barrie, Ontario, for 2 years as part of a multicenter study of the hydrophobic acrylic one-piece IOL.

No unanticipated adverse visual effects and no lens complications were seen.

"At 2 years, 15 out of 17 patients in my practice had 20/20 or better best-corrected vision, and 100% of patients were 20/40 or better uncorrected. To date, there have been no YAG capsulotomies, and the lens has demonstrated excellent stability," Dr. Nixon said.

The investigational lens, which has an overall 13-mm diameter and a true 6-mm optic, offers several benefits, Dr. Nixon said. In addition to its hydrophobic material, it has a surface treatment that's designed to reduce the tackiness of the acrylic material and aid in unfolding. It also has a 360° uninterrupted square edge design and a frosted edge to minimize edge glare.

"The 360° square edge provides for uninterrupted contact with the optic on the posterior capsular bag," Dr. Nixon said. "Unlike traditional single-piece lenses, this one is designed to mitigate or prevent lens epithelial cell migration along the haptic."

The lens is designed to offset optic relative to the haptic, providing for three points of fixation in the capsular bag-two in the equator of the capsular bag affixed to the haptic, and one on the posterior surface of the lens that exerts downward pressure on the posterior optic to the anterior surface of the posterior capsule. "This further emphasizes the barrier effect of the 360° square edge," he said.

It also has polished optic loops to reduce friction on transmission down the cartridge as well as allow for easy dialing of the lens once it is in the bag.

Dr. Nixon said that time-lapse photography from the time of implantation out to 18 months shows no evidence of decentration or rotation of the lens. Also, minimal capsular fibrosis has been seen, and in his studies out to 27 months, the lens still has a clear posterior capsule.

The results presented by Dr. Nixon compared a FDA multicenter study of 123 patients with 1-year results, and the FDA grid for posterior chamber IOLs was used as a historic control.

Four subjects in the FDA study developed cystoid macular edema, and one subject underwent a lens exchange, but this was performed because of a torn haptic related to improper lens folding at the time of surgery. Additionally, one subject underwent pars plana vitrectomy during the 1-year follow-up.

"This is a safe and effective lens for intraocular implantation. It has an excellent track record," Dr. Nixon said.