Silicone IOL patients need YAG treatment sooner, more often than acrylic patients

Fifty-five percent of all patients with acrylic IOLs showed no signs of capsular opacification during the entire 4-year study.

Issue: November 1, 1999

VIENNA, Austria — Compared with AcrySof IOL patients, those with second generation silicone lenses are more likely to require Nd:YAG laser capsulotomy, and will need it sooner, according to a study by Paul H. Ernest, MD, in private practice in Jackson, Mich.

Dr. Ernest’s study, which includes some patients with as much as 4 years of follow-up data, looked at 154 patients who received either an Alcon (Fort Worth, Texas) AcrySof MA30 IOL or a second generation silicone Allergan (Irvine, Calif.) SI40NB lens. The study compared silicone and acrylic IOLs in the same bilaterally implanted patients.

“There were significantly more eyes in our silicone lens group that had capsular opacification than in our acrylic lens group,” Dr. Ernest told attendees of the European Society of Cataract and Refractive Surgeons meeting. “More than twice the eyes of a silicone lens require capsulotomies compared with the acrylic lens.”

Additionally, Dr. Ernest found that the time interval for a YAG to be performed was longer for the AcrySof lens. AcrySof lens patients went without a capsulotomy for approximately 42 months, compared with 32 months for the silicone lens patients.

The average age of the implant recipients was 74 years, with a range of 53 to 98 years. By a margin of 2 to 1, the patients were female. The mean follow-up time was about 114 weeks, ranging up to 4 years, and with a standard deviation of 44 weeks.

“Our study design had no exclusion criteria,” Dr. Ernest said. “The lenses were randomized to the first eye and then automatically defaulted to the second eye. So if a silicone implant was inserted in the first eye, an acrylic was inserted in the second, and vice versa.”

45% versus 73%

At any given time during the study, 45% of AcrySof lens patients had opacification, while 73% of silicone patients had opacification.

“Capsular opacification at any visit was 2:1 in silicone lenses, in favor of the acrylic,” he said. Fifty-five percent of all patients with acrylic IOLs showed no signs of capsular opacification during the entire 4-year study, where only 27% had a similar result with the silicone lenses, he reported.

The mean time for a YAG to be performed in months was 41.9 months for AcrySof and only 31.9 months for silicone. Again, this was statistically significant with a P value of .007.

The factors that influence posterior capsule opacification development includes the age of the patients, residual lens epithelial cells, as well as the technique and removal, the implant design, and optic material, he said. Considering this array of factors, Dr. Ernest said AcrySof appears to be a better choice.

Surgeries were all performed by Dr. Ernest within a 2-month time period. All incisions were 3.2 mm in width, temporal location, limbal and sutureless.

At regular intervals, capsular opacification was measured using a slit lamp, and scoring was subjective by the surgeon. He also measured the visual acuities with a standard eye chart.

Patients who complained about blurred or unclear vision, those with measurable capsular opacification and those with a reduction in the visual acuity of two lines from the time of surgery were referred for capsulotomy.

For Your Information:

Paul H. Ernest, MD, can be reached at TLC Eye Care of Michigan, 1116 W. Ganson, Jackson, MI 49101; (517) 782-9436; fax: (517) 782-3001; e-mail: paul.ernest@izr.com. Dr. Ernest has no direct financial interest in any of the products mentioned in this article. He is a paid consultant for Alcon.