The AcrySof ReSTOR apodized diffractive IOL (model MA60D3, Alcon Laboratories Inc.) provides patients with excellent near visual acuity without compromising distance vision.
"New apodized diffractive IOLs have 12 diffractive zones. Light enters both distance and near powers in the central region, which gradually blends between powers for large pupils," Dr. Kohnen said. "The development of this lens should provide a broad functional vision range by enhancing near vision, maintaining distance vision, and minimizing visual disturbances."
He explained at the annual meeting of the American Academy of Ophthalmology last year that the advantages of the AcrySof biocompatible material come into play with this lens.
To test the effectiveness of this lens, Dr. Kohnen participated in an open, multicenter (eight study sites), phase II clinical trial to evaluate the safety and effectiveness of the IOL. The study included 127 patients; 119 patients underwent bilateral implantation of the IOL. Surgeons from the United Kingdom, Germany, and France carried out the implantations.
All patients were at least 20 years of age and provided written informed consent, had less than 1 D of astigmatism, had no other ocular disorder other than bilateral cataract, and underwent bilateral implantation. The investigators evaluated distance vision, near visual acuity, contrast sensitivity, patient satisfaction, and dependence on spectacles.
The patients' visual function was evaluated in the first eye that underwent surgery, the second eye that underwent surgery, and then binocularly. At the 6-month postoperative visit following the second implantation, Dr. Kohnen reported that 85% of patients had an uncorrected distance visual acuity of 20/40 or better with the first eye, 94% with the second eye, and 99% with binocular vision. For the best-corrected distance visual acuity, the respective percentages were 97%, 100%, and 100%. The FDA grid is 92.5%, according to Dr. Kohnen, professor of ophthalmology, Johann Wolfgang Goethe-University, Frankfurt, Germany.
When the best-corrected distance visual acuity was measured, the investigators found an increase in the first eye that underwent surgery, the second eye that underwent surgery, and binocular vision to about 20/20.
The results of the measurement of the best-corrected near visual acuity at 33 cm showed that 92%, 95%, and 99% of eyes had 20/40 or better, respectively, for the eyes that underwent surgery first, the eyes that underwent surgery second, and the binocular vision.
Contrast sensitivity testing showed that with 25% contrast 94% of the first eyes that underwent surgery achieved 20/40 or better and with 9% contrast 59% of the first eyes achieved 20/40 or better. When the second eyes that underwent surgery were tested at 25% contrast, 95% achieved 20/40 or better and with 9% contrast 68% of the second eyes achieved 20/40 or better.
Nighttime visual disturbances Visual disturbances were present in this patient population. On a scale of 1 to 7 with 0 indicating none and 7 indicating severe, the mean score was 0.4; night vision disturbances, 0.62; halos, 1.628, and glare/flare, 1.92.
Two patients underwent explantation of the IOL, one because of incorrect lens power and the other because of intolerable glare.
Patient satisfaction with the lens was high, with 92% indicating that they would have the second lens implanted. The percentage increased to 95.7% patient satisfaction after the second lens was implanted.
Six months after the second eye surgery, 88% of the patients did not wear glasses for distance vision and 84.6% did not wear glasses for near vision. Twelve percent of patients reported that they sometimes use glasses for near vision and 2.6% reported that they sometimes wear glasses for distance vision, Dr. Kohnen reported.