Lens can be precisely adjusted with light after implantation

San Francisco-A Light Adjustable Lens (LAL) (Calhoun Vision) has been precisely adjusted after implantation to correct spherical and astigmatic refractive error. Thus far, the follow-up in human eyes is out to 24 months postoperatively, and the LAL appears to be biocompatible in these eyes, said Arturo Chayet, MD. He reported the update on the clinical results for spherical correction at the annual meeting of the American Society of Cataract and Refractive Surgery.

Twenty-four eyes had an LAL implanted. The LALs in 12 of the eyes were intentionally treated so that the patient would have residual myopia between –1 and –2 D, and the other 12 were treated so that the patients would have residual hyperopia of 1 to 2 D. Dr. Chayet explained that the adjustments to eliminate the residual refractive errors were scheduled for within 2 weeks after the implantation of the LAL.

"In the 12 eyes with hyperopic correction, 10 of the 12 eyes were within 0.25 D of the intended refraction," reported Dr. Chayet, medical director, Institute de Oftalmologia, Tijuana, Mexico. "The other two eyes were within 0.5 D of the goal refraction. In the patients with myopic correction, 11 of the 12 eyes were within 0.25 D of the intended refraction; the remaining one eye was within 0.5 D of the intended refraction."

Immediately after cataract surgery and implantation of the LAL with adjustment, the uncorrected visual acuity (UCVA) in the patients with myopia was 20/40 or better in all patients, with most patients having 20/25 or better vision. Many patients had 20/20 or better vision, according to Dr. Chayet.

No eyes have lost any lines of best-corrected visual acuity.

"We are very satisfied with the results regarding the safety of the LAL," he said.

"The adjustment and the 'lock in' of the refraction are comparable to performing a YAG capsulotomy," Dr. Chayet said. "The procedure is very simple to do and very well tolerated by the patients. We can adjust myopic and hyperopic spherical refractive error within 0.25 D of the intended refraction. All patients had improved UCVA without loss of the best-corrected visual acuity."

The patients who will benefit most from this type of technology are those scheduled for implantation of a monofocal LAL who desire an optimized UCVA after routine cataract surgery, Dr. Chayet said. Another group of patients who will benefit are those with IOLs implanted to correct presbyopia; in the future the platform can be applied for multifocal or accommodating IOLs, he added.

"We also envision that this technology can be used as a piggyback implant to make the refractive results more accurate and can also be applied to phakic IOLs," Dr. Chayet concluded. "This technology is one of the most exciting. In the future there will be millions of patients who need cataract surgery and refractive procedures, especially LASIK, and this procedure should provide us with the ability to do a good refractive calculation and provide perfect outcomes."