Self-assessed visual results found similar with blue-light-blocking and aspheric IOLs

Garden City, KS-Cataract surgery patients do not notice a significant difference in vision between two lenses-the blue-light-blocking spherical SN60AT IOL (AcrySof Natural, Alcon Laboratories) and the aspheric SN60WF IOL (AcrySof IQ, Alcon Laboratories)-according to the results of a small, randomized, fellow eye controlled study. Luther L. Fry, MD, a private practitioner in Garden City, KS, reported the results.

In the investigation, 27 consecutive patients undergoing surgery for bilateral operable cataracts were randomly assigned to receive the SN60AT or the SN60WF lens in their first eye and then had the alternate IOL implanted when the second eye surgery was performed 3 weeks later. Self-assessed vision was evaluated at 3, 6, and 12 months after the second eye surgery by telephone survey using a simple questionnaire. At all time points, the majority of patients (78% to 84%) reported they detected no difference in vision between their two eyes. Among the patients who did express a preference, more favored the spherical IOL compared with the aspheric design.

"These outcomes were surprising because I expected patients would find their vision was better with the aspheric lens, especially in low-contrast situations such as at night. However, it has been reported that near and intermediate acuity are better with the SN60AT compared with the aspheric model. Perhaps the results can also be explained in part by the possibility that a one-size-fits-all approach to asphericity does not match the requirements of the individual cornea," Dr. Fry said.

For routine use?

Dr. Fry decided to undertake the study when the SN60WF lens first became available in order to collect objective data that would allow him to decide if that new IOL should be used routinely. Patients were eligible to participate in the study if their required IOL power was in the range available for the two implants and if they did not have diabetes, maculopathy, or any other ocular pathology that might result in vision less than 20/20.

All patients were informed that they would have a new and supposedly improved IOL placed in their first eye and a slightly different, new and supposedly improved IOL in their second eye. In addition, patients were told they would be contacted by phone after the surgery to ask how they were doing and if they noticed any difference between eyes.

"We decided that any patient who seemed uncomfortable about the surgical plan would be excluded and have surgery with conventional IOL implantation bilaterally. None of the patients we approached, however, expressed any concern," Dr. Fry said.

The survey to determine patient preference was administered by an experienced certified ophthalmic technician, who asked the following questions:

"Admittedly this was a low-tech approach, but I think it was adequate for providing the information we were seeking," Dr. Fry said.

At 3 months, 21 (78%) patients found no difference between eyes, two (7%) preferred the aspheric IOL, and four (15%) considered the blue-light-blocking spherical IOL better. At 6 months, two patients were deceased. Among the remaining 25 patients, three (12%) thought their vision was better in the eye with the aspheric IOL and four (16%) considered the eye with the SN60AT better. After 1 year, 18 (72%) patients again considered their vision similar between eyes, while among those who expressed a preference, only two (8%) considered the eye with the aspheric IOL better while five (20%) preferred the eye with the SN60AT implanted.