Hydrophilic acrylic IOL yields promising early results

The single-piece lens inserted through a 1.8-mm incision showed good visual acuity and stability, study participant says.

ByErin L. Boyle

A hydrophilic acrylic IOL inserted through a 1.8-mm cataract incision showed good visual function, according to early data from an ongoing multicenter study.

Thomas Kohnen

The single-piece Akreos MI60 IOL (Bausch & Lomb) also had good centration and minimal tilt, Thomas Kohnen, MD, said.

“The MI60 IOL is safe and effective when implanted through a 1.8-mm incision,” he said. “The implanted intraocular lenses showed excellent centration and a low degree of optic tilt.”

The lens has an aberration-free aspheric optic, four-point fixation, 360° posterior barrier optic edge and 10° haptic angulation. It is designed to be inserted through a 1.8-mm corneal incision with wound-assisted linear injection, Prof. Kohnen said.

Prof. Kohnen presented 6-month data from the 2-year prospective study at the American Society of Cataract and Refractive Surgery meeting in Chicago, U.S.A.

He said he plans to present more data at the European Society of Cataract and Refractive Surgeons meeting in September.

Patient group, surgical technique

The study, which is being conducted at five centers in France, Germany, Italy, Spain and Sweden, includes 125 patients who underwent cataract extraction with implantation of the MI60 IOL between August 2006 and October 2007, Prof. Kohnen said.

Outcome parameters include visual acuity, refraction, stability, higher-order aberrations and posterior capsular opacification. Endpoints range from 1 to 780 days, he said.

Interim data were available for 90 patients. These patients had a mean age of 69 years (range, 47 to 84 years); 40% of the patients were men, and 60% were women. Slight to moderate cataracts appeared in 67.2% of patients; very dense cataracts were found in 32.8% of patients.

Patients underwent biaxial phacoemulsification with topical anesthesia. A clear corneal incision was performed in 72% of patients; mean incision size was 1.5 ± 0.29 mm. Viscoelastics used were Amvisc Plus (Bausch & Lomb) in 59% of eyes and Coatel (Bausch & Lomb) in 37% of eyes.

Capsulorrhexis ranged from 4 mm to 6 mm and was performed on the optic in 96% of cases, Prof. Kohnen said.

Mean incision enlargement was 1.7 ± 0.2 mm. IOL injection was performed using a Viscoject system (Medicel) with a 1.8-mm cartridge. Sutures were not used in 94.4% of eyes. The mean power of implanted lenses was 21.3 D ± 2.6 D.

Centration, visual acuity and aberrations

Investigators used the Nidek EAS-1000 Scheimpflug camera to measure IOL tilt and centration. At the study site in Frankfurt, investigators found that at 7 to 14 days in 17 patients, mean centration was 0.29 mm. At 30 to 60 days in 14 patients, mean centration was 0.25 mm, Prof. Kohnen said.

Preoperative spherical equivalent was –0.53 D ± 2.93 D. Four to 6 months after surgery, 90 patients had spherical equivalent of 0 D ± 0.92 D, he said.

At 6 months after surgery, 86 patients had a mean logMAR uncorrected visual acuity of 0.24 ± 0.25; at the same interval, 85 patients had a mean logMAR best corrected visual acuity of 0.02 ± 0.15.

Investigators in Germany and Sweden used the Zywave aberrometer (Bausch & Lomb) to measure higher-order aberrations in 4-mm, 5-mm and 6-mm pupils at 30 to 60 days and 120 to 180 days. Higher-order aberrations decreased steadily in all three pupil size groups, Prof. Kohnen said.

For more information:

Thomas Kohnen, MD, can be reached at Johann Wolfgang Goethe-Universitat, Klinik fur Augenheilkunde, Theodor-Stern-Kai, Frankfurt/Main, Germany; +49-069-6301-6739; fax: +49-069-6301-3893; e-mail: kohnen@em.uni-frankfurt.de. Prof. Kohnen is a consultant for Bausch & Lomb.

Bausch & Lomb, maker of the Akreos MI60 IOL, can be reached at Bausch & Lomb House, 106-114 London Road, Kingston-Upon-Thames, Surrey KT2 6TN, England; Web site: www.bausch.com.

Matt Hasson is an OSN Staff Writer who covers all aspects of ophthalmology. He focuses on regulatory, legislative and practice management topics. OSN Staff Writer Erin L. Boyle contributed to this article.