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

Posterior capsule opacification after phacoemulsification: silicone CeeOn Edge versus acrylate AcrySof intraocular lens

PURPOSE

To compare the rates and morphologic features of posterior capsule opacification (PCO) after small-incision phacoemulsification and in-the-bag implantation of 2 foldable intraocular lenses (IOLs) over an 18-month follow-up.

SETTING

Departments of Ophthalmology, Hospital of Conegliano, Conegliano, and Maggiore Hospital of Bologna, Bologna, Italy.

METHODS

In an open clinical study, 78 cataract patients were randomly selected to have implantation of a silicone CeeOn Edge (Pharmacia) or acrylate AcrySof (Alcon) IOL after phacoemulsification cataract surgery. All the patients were operated on using a standard technique and in-the-bag IOL implantation. One eye in each patient was studied. Morphologic evaluation of PCO was performed using Evaluation of Posterior Capsule Opacification software.

RESULTS

At 18 months in the CeeOn Edge group, 36 eyes (90%) had a clear posterior capsule and 4 (10%) had PCO that did not affect visual acuity. In the AcrySof group, 26 eyes (68%) had a clear posterior capsule, 11 (29%) had PCO that did not affect visual acuity, and 1 (3%) had PCO with a decrease of 2 or more lines of visual acuity that required a neodymium:YAG laser capsulotomy. No eye developed Elschnig pearls or stretched folds in the bag. The postoperative best corrected visual acuity ranged from 0.8 to 1.0 in 96% in the CeeOn Edge group and in 92% in the AcrySof group. No IOL haze or discoloration was observed in the CeeOn Edge group. Mild IOL decentration and tilting occurred in 4 AcrySof eyes; however, no glistenings were found any AcrySof IOL.

CONCLUSIONS

Both the CeeOn Edge and AcrySof groups had a low incidence of PCO after an 18-month follow-up. The CeeOn Edge group had significantly less PCO than the AcrySof group. These results confirm that IOLs with square truncated edges create a barrier effect at the optic edge, reducing the overall incidence of PCO.

Retrospective evaluation of intraocular lenses in adults younger than 60 years

Data from the U.S. Food and Drug Administration, the American Academy of Ophthalmology's National Eyecare Outcomes Network, and Storm Eye Institute databases were analyzed for short- and long-term safety and efficacy outcomes of intraocular lens (IOL) implantation in adults younger than 60 years and 60 years and older. Statistical analyses for significance were performed where appropriate. A comprehensive literature review was conducted to identify safety and efficacy outcomes and their relationship to patient age at the time of implantation. Analyses established that the performance of IOLs in adults younger than 60 years was comparable to that in adults older than 60 years and supported the use of IOLs in the younger adult population.

Changes in posterior capsule opacification after poly(methyl methacrylate), silicone, and acrylic intraocular lens implantation

PURPOSE

To prospectively evaluate the progression of posterior capsule opacification (PCO) after poly(methyl methacrylate) (PMMA), silicone, and acrylic intraocular lens (IOL) implantation.

SETTING

Hayashi Eye Hospital, Fukuoka, Japan.

METHODS

Three hundred eyes of 300 patients scheduled to have IOL implantation were initially randomized into 3 groups based on IOL type: PMMA, silicone, or acrylic. Of the 300 eyes, 269 completed the follow-up. The PCO density in these eyes was measured 1 week and 3, 6, 12, 18, and 24 months postoperatively using special computer software developed for the Scheimpflug videophotography system. Visual acuity and the incidence of neodymium:YAG (Nd:YAG) laser capsulotomy were also examined.

RESULTS

Three months postoperatively and later, the mean PCO value in the PMMA group increased significantly (P <.0001); the increase in the silicone and acrylic groups was not significant. The PCO value in the PMMA group was significantly greater than in the silicone or acrylic group (P <.0001). The PCO value in the acrylic group was slightly less than in the silicone group at 18 and 24 months, but the difference was marginal. The survival rate not requiring Nd:YAG capsulotomy was least in the PMMA group, followed by the silicone and acrylic groups in that order (P <.0001). The mean logMAR visual acuity in the PMMA group increased postoperatively and was worse than in the silicone or acrylic group.

CONCLUSIONS

The degree of PCO after PMMA IOL implantation progressed significantly with time, while the progression after silicone and acrylic IOL implantation was slight. Therefore, PCO in eyes with a PMMA IOL was significantly more extensive than in those with a silicone or acrylic IOL and resulted in marked impairment of visual acuity.

Determining the imaging quality of intraocular lenses

PURPOSE

To validate the proposed optical requirements of a draft international standard for intraocular lenses (IOLs).

SETTING

Eight optical testing laboratories in the United States, Germany, Japan, and The Netherlands.

METHODS

The testing laboratories performed modulation transfer function (MTF) tests on various IOLs using a model eye and visual resolution tests in air. Each laboratory performed duplicate measurements on a set of 43 lenses that was circulated among the testing laboratories.

RESULTS

The interlaboratory tests showed that the MTF measurements using a model eye had better repeatability and reproducibility than the more common industry practice of resolution testing in air with parallel light and the United States Air Force three-bar target. However, the two methods correlated well. The commonly applied criterion that an IOL resolve in air at least 60% of the Rayleigh cutoff spatial frequency corresponded to a minimum requirement of 0.43 MTF units at 100 mm-1 in a model eye.

CONCLUSIONS

Either criterion may be applied in accordance with a proposed international standard for IOLs. The model eye method can be applied over a broader range of dioptric powers and is relevant for materials that interact with aqueous. Both tests appear to have a greater ability to detect unwanted surface aberrations than resolution testing of IOLs in a water cell using parallel light, a method described in the current American National Standards Institute standard.

Three year prospective, randomized evaluation of intraocular lens implantation through 3.2 and 5.5 mm incisions

PURPOSE

To compare the long-term clinical results of two small incision cataract surgery procedures.

SETTING

Seven centers in Japan.

METHODS

Two hundred eyes were randomly assigned to receive a silicone intraocular lens (IOL) through a 3.2 mm incision or a poly(methyl methacrylate) (PMMA) IOL through a 5.5 mm incision. Except for incision size and implantation technique, the surgical methods were identical. Uncorrected and corrected visual acuity, keratometry, flare-cell intensity, specular microscopy, and neodymium:YAG (Nd:YAG) laser posterior capsulotomy rate were analyzed up to 3 years after surgery.

RESULTS

Eyes in the 3.2 mm incision group had significantly better uncorrected and corrected visual acuity in the early postoperative period and lower aqueous flare intensity immediately after surgery, but these differences disappeared after the first postoperative month. However, surgically induced astigmatism was significantly less in the 3.2 mm incision group than in the 5.5 incision group throughout the study. The Nd:YAG laser capsulotomy rate was higher in the silicone IOL group (23.5% at 3 years postoperatively) than in the PMMA IOL group (18.4%) but the difference was not statistically significant.

CONCLUSION

Smaller incision cataract surgery led to early recovery of visual function in the short term and less induced astigmatism in the long term.

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.

Prospective study of the SI-40NB foldable silicone intraocular lens

PURPOSE

To evaluate the surgical performance and postoperative outcomes of 100 consecutive implantations of the new AMO PhacoFlex SI-40NB foldable intraocular lens (IOL).

SETTING

Concord Hospital and Dalcross Private Hospital, Sydney, Australia.

METHODS

This prospective study comprised 100 consecutive patients who had endocapsular phacoemulsification cataract surgery with implantation of the AMO SI-40NB IOL, which has a silicone optic and poly(methyl methacrylate) (PMMA) haptics. Patients were excluded if trabeculectomy was performed concomitantly. The main outcome measures were control of folding, ease of implantation, centration, intraoperative and postoperative complications, and visual acuity. A minimum of 4 months follow-up was planned.

RESULTS

Mean follow-up was 4.3 months +/- 2.1 (SD) (range 1 to 12 months). The lens permitted excellent control of folding and insertion, as well as excellent centration at surgery and 4 months. There was one lens-related intraoperative complication because of crimping of the trailing lens haptic. Postoperative complications were minimal, and 92% of patients achieved a visual acuity of 20/20 or better at 1 and 4 months. Excluding the eyes with retinal pathology, 100% achieved 20/20 or better at 4 months.

CONCLUSION

The AMO SI-40NB three-piece silicone IOL with PMMA haptics provided excellent operative control, centration, and visual outcome and is suitable for small incision cataract surgery.