Use of the YAG laser with a seven-micron spot in pseudophakic eyes

Clinical assessment of long-term safety and efficacy of a widely implanted silicone intraocular lens material

PURPOSE

To summarize the long-term safety and efficacy, in a large series of patients, of intraocular lenses made from a second-generation silicone material (AMO SLM-2/UV) widely used as an intraocular lens material.

METHODS

This was a prospective study of adult patients who received posterior-chamber intraocular lenses with an optic composed of a high-index-of-refraction, ultraviolet-light-absorbing silicone (AMO SLM-2/UV). In 501 patients, clinical data through 3 years postoperative are presented. Postoperative measurements included spectacle-corrected visual acuity, occurrence of postoperative sight-threatening or lens-related complications, and adverse reactions. Results were compared with the standards established by the US Food and Drug Administration (FDA) for polymethylmethacrylate lenses.

RESULTS

At 1 year, 95.2% (496/521) of all patients in group I achieved corrected visual acuity of 20/40 or better. This compared well with the standard reported for polymethylmethacrylate lenses (88%, 2,521/2,864). At 3 years, 94.3% (347/368) of best-case patients achieved corrected visual acuity of 20/40 or better. The rate of sight-threatening complications reported at the final postoperative examination at 3 years was 2.0% (10/501). The rate of Nd:YAG capsulotomy was 27.5% (138/501) through 3 years.

CONCLUSION

Lenses made of the SLM-2/UV silicone material demonstrated safe and effective performance through long-term follow-up at a level equal to or better than established standards for polymethylmethacrylate lenses.

Long-term clinical results of AMO PhacoFlex model SI-18 intraocular lens implantation

The AMO PhacoFlex Model SI-18 was the first commercially available three-piece silicone intraocular lens (IOL) for use in small incision cataract surgery. Allergan Medical Optics' silicone IOLs have been implanted in more than 750,000 patients worldwide over the past eight years. This report of the FDA clinical investigation of the AMO PhacoFlex model SI-18 IOL summarizes one year follow-up data from the initial premarket approval clinical trial on 500 core patients implanted with the SI-18 lens. One-year follow-up data from 5,860 patients in the modified core group and three-year follow-up data on the 500 patient core/modified core group are also presented. At three years postoperatively, 91.3% of best case core/modified core patients achieved 20/40 or better corrected visual acuity. Overall incidence of persistent complications at three years was 3.2%.

Posterior capsule opacification

A complication of extracapsular cataract extraction with or without posterior chamber intraocular lens (PC-IOL) implantation is posterior capsule opacification. This condition is usually secondary to a proliferation and migration of residual lens epithelial cells. Opacification may be reduced by atraumatic surgery and thorough cortical clean-up. Clinical, pathological and experimental studies have shown that use of hydrodissection, the continuous curvilinear capsulorhexis and specific IOL designs may help reduce the incidence of this complication. Capsular-fixated, one-piece all-polymethylmethacrylate PC-IOLs with a C-shaped loop configuration and a posterior convexity of the optic are effective. Polymethylmethacrylate loops that retain "memory" create a symmetric, radial stretch on the posterior capsule after in-the-bag placement, leading to a more complete contact between the posterior surface of the IOL optic and the taut capsule. This may help form a barrier against central migration of epithelial cells into the visual axis. Various pharmacological and immunological methods are being investigated but conclusive data on these modalities are not yet available.