Phakic IOL offers excellent outcomes for FDA cohort

March 15, 2005

Atlanta—Up-to-date results from participants in the FDA clinical trial of the recently approved Verisyse phakic myopic IOL (Advanced Medical Optics) demonstrate that implant provides excellent refractive outcomes with a good safety profile, according to R. Doyle Stulting, MD, PhD.

"There have been minimal complications with this phakic implant and adequate training in the surgical technique allows for a short learning curve. Those features and the excellent results achieved with the Verisyse phakic myopic IOL are translating into high patient and surgeon satisfaction," commented Dr. Stulting, professor of ophthalmology, Emory University, Atlanta.

The Verisyse phakic myopic IOL was approved for implantation in the United States on Sept. 10, 2004. The FDA clinical trial that was the basis for the approval enrolled patients ages 21 to 50 years with stable refraction and axial myopia that could be addressed with -5 to -20 D of correction. Eligible eyes had to have a minimum anterior chamber depth of 3.2 mm and a minimum endothelial cell count of 2,000 cells/mm2. Eyes with up to 2.5 D of cylinder were allowed, although no cylinder correction was performed.

Considering eyes with preoperative best spectacle-corrected visual acuity (BSCVA) 20/20 or better, 92% had uncorrected visual acuity (UCVA) of 20/40 or better at 3 years and 67.1% were seeing 20/25 or better uncorrected.

"Remember the implant was available in power steps of only 1 D and there was no cylinder correction. Therefore, we anticipate even better results in post-approval clinical use," Dr. Stulting said.

Predictable, reliable results Analyses of the refractive outcomes showed the results were highly predictable, with stability reached early. Seventy-two percent of eyes were within 0.5 D of target refraction and 94.8% were ±1 D. Mean SE was near emmetropia on the first day after surgery and showed little change thereafter-the mean change between 6 months and 1 year was -0.03 D and there was a -0.01-D change from months 24 to 36.

Among 412 subjects who had at least 1 year of follow-up, about 90% expressed good to excellent satisfaction.

BSCVA safety analyses based on data from 308 first eyes seen after 3 years showed two-thirds of eyes achieved 1 or more lines of improvement in BSCVA, while only 8% lost any BSCVA and only 1.3% lost 2 lines. In addition, an increasing proportion of eyes reached BSCVA of 20/15 over time-5% at 1 year, 15% at 2 years, and 24% at 3 years.

"We think that phenomenon is due to more than magnification because it increased progressively with time," Dr. Stulting noted.

Endothelial cell count data were analyzed in various ways by the sponsor and the FDA. An original paired analysis based on the entire cohort showed a mean loss from baseline of just 0.35%. Re-analyses showed an equivalent yearly rate of loss of 1.27% based on the consistent cohort and 1.59% considering the overall count. No eyes have shown corneal edema at visits past 3 months after surgery.

"The latest data represent recounts of images that were retained and they are regarded as the most accurate count of data available. However, in any of the analyses, the changes in endothelial cell density provide no reason for alarm, and they are not significantly different from guidance," Dr. Stulting said.