Phakic lens produces good long-term results in European study
Reassuring data come from the absence of pupil ovalization and endothelial stability at 3 years.
ROME Three years of follow-up in a European multicenter study demonstrate that the Alcon AcrySof phakic IOL is a suitable option for the correction of high to moderate refractive error, with good visual acuity results, a high degree of predictability, refractive stability over time and absence of major complications, according to a surgeon here.
The AcrySof phakic IOL is manufactured in 6-mm meniscus optic with an overall length of 12.5 mm to 14 mm. Refractive power ranges from 6 D to 16 D in 0.5 D increments. It is angle-supported and has, therefore, raised a lot of interest because some models of phakic IOLs have showed a high rate of late endothelial cell loss, said OSN Europe/Asia-Pacific Edition Associate Editor Jorge L. Alió, MD, PhD, who presented the 3-year study results at the winter meeting of the European Society of Cataract and Refractive Surgeons.
Other clinical studies on this lens are currently under way in Canada and in the United States, but Europe currently has the largest cohort of patients (190) and the longest follow-up. The endpoint of the study will be at 5 years.
In the European study, inclusion criteria were stable refraction for at least 12 months before surgery, anterior chamber depth of at least 3.2 mm and a sufficiently high endothelial cell density.
We excluded patients with more than 2 D of astigmatism, as astigmatic enhancement was not allowed in this investigation, Dr. Alió said.
The mean cumulative uncorrected visual acuity at 3 years was 20/40 or better in 97% of the cases, 20/25 or better in 73% of the cases and 46% achieved 20/20. Only one eye was worse than 20/40.
Best corrected visual acuity, which included the correction of astigmatism with spectacles, was 20/20 or better in 81% of the cases, 20/25 or better in 98% of the cases, 20/30 or better in 99% of the cases and no cases were worse than 20/40.
Some gain of BCVA over the years is usually seen after implantation of phakic IOLs because of the magnification of retinal image induced by the lens. Significantly, 80% of the cases did not change or gain one line in which the mean preop correction was 10 D, whereas higher corrections were obtaining a larger amount of lines, Dr. Alió said, adding that the manifest refraction was extremely stable.
We had a number of preoperative cases with 10.4 D of spherical equivalent. The mean refraction after implantation was 0.25 D or better, and no change was seen over the entire postoperative course, he said.
Overcoming major concerns
The lens was well-regarded concerning the issue of endothelial integrity. Material and design make this lens respectful of the anterior chamber anatomy and endothelium, Dr. Alió said.
Evolution of endothelial cell density, hexagonality and coefficient of variation were extremely stable over 3 years, he said.
No adverse events such as endophthalmitis, hyphema, hypopyon, lens dislocation, cystoid macular edema, pupillary block, retinal detachment, corneal edema or iritis were reported.
Raised IOP requiring treatment during the immediate postoperative follow-up was found in 10 cases and was related to the inadequate removal of viscoelastic.
Cataract formation occurred in seven cases, and all cases are related to a well-established diagnosis unrelated to the phakic IOL, Dr. Alió said.
Goniosynechiae was reported as a marginal finding in a few cases and was minimal in terms of size and dimensions.
We had a small number of secondary interventions, he said. On the whole, we can conclude that all minor complications were related to the learning curve of the surgeons.
Pupil ovalization, another major concern with angle-supported lenses, was absent in all cases at 3 years.
All of the patients in the European study were implanted unilaterally. Other phakic lenses were implanted in the fellow eye.
These data are not included in the study, but we observed that the preference of all our patients goes to the eye implanted with the AcrySof (phakic lens) due to the better quality of vision and lack of photic phenomena, Dr. Alió said. by Michela Cimberle
- Jorge L. Alió, MD, PhD, can be reached at Vissum, Instituto Oftalmologico de Alicante, Avda. de Denia, s/n, 03016 Alicante, Spain; +34-965-150-025; fax: +34-965-151-501; e-mail: email@example.com. Dr. Alió is a clinical investigator for Alcon.