Higher rate of laser capsulotomy found with multifocal IOL

An interaction between posterior capsule opacification and the multifocal optics may cause a decrease in vision.

Michael J. Taravella

Implantation of a multifocal IOL correlated with a higher incidence of Nd:YAG laser capsulotomy than a similarly designed monofocal lens, a study found.

Implantation of the multifocal IOL required laser capsulotomy about three times more frequently than implantation of the monofocal IOL, Michael J. Taravella, MD, the corresponding author, told Ocular Surgery News.

The multifocal lens does not appear to induce more posterior capsule opacification than the monofocal lens. Rather, poor visual quality stemmed from an interaction between posterior capsule opacification and the multifocal optics, Dr. Taravella said.

“Our own clinical observation is that the posterior capsule looks about the same in patients with both lenses,” he said. “It doesn’t seem, for instance, that posterior capsule opacification is more aggressive. We believe it’s just because of the interaction with the multifocal optics.”

The study was published in the Journal of Refractive Surgery.

Retrospective analysis

The study authors compared posterior capsulotomy rates for patients implanted with the AcrySof SN60WF one-piece monofocal IOL or the AcrySof ReSTOR SN60D3 or SA60D3 multifocal IOL (Alcon).

The AcrySof SN60D3 and SA60D3 have been discontinued in the U.S. and replaced by the aspheric model, SN6AD1, according to an e-mail from Alcon.

The retrospective study included 142 eyes implanted with the multifocal IOL. A comparator group comprised 275 eyes implanted with the monofocal lens.

Patients in the multifocal IOL group had a mean age of 65.5 years, while those in the monofocal IOL group had a mean age of 65.6 years.

Mean outcome measures were preoperative corrected distance visual acuity and incidence, time and onset of posterior capsule opacification. Average postoperative follow-up was 22 months (range: 2 to 41 months).

Study results showed that 22 eyes in the multifocal IOL group (15.49%) and 16 eyes in the monofocal group (5.82%) underwent capsulotomy. The between-group difference was statistically significant (P = .0014).

The SA60D3 multifocal IOL had a capsulotomy rate of 15.04% and the SN60D3 multifocal IOL had a capsulotomy rate of 17.24%; the difference was not significant, the authors said.

Eyes in the multifocal IOL group underwent capsulotomy after a mean postoperative interval of 8.8 months, while those in the monofocal IOL group underwent capsulotomy a mean 10.4 months postop. The difference was not statistically significant.

Eyes in the multifocal IOL group had a mean preoperative logMAR corrected distance visual acuity of 0.113, and eyes in the monofocal IOL group had a mean preoperative corrected distance visual acuity of 0.244. The difference was statistically significant (P = .073).

Observations and pearls

“What we hypothesize is that multifocal IOLs already have a decrease in contrast sensitivity and you get an additive effect when you have posterior capsule opacification,” Dr. Taravella said. “So, patients are more likely to become more symptomatic with minimal opacification with a ReSTOR or a multifocal lens than they would with the same degree of opacification if it’s not a multifocal lens.”

The main indication for laser capsulotomy was patient complaints of diminished vision. The most common complaints were blurred reading vision and poor overall vision, Dr. Taravella said.

It was difficult to distinguish glare and halo caused by posterior capsule opacification or by multifocal optics in the eyes implanted with multifocal IOLs.

“It’s hard to know and really sort out when you have a patient with capsule opacification vs. a multifocal IOL, which is the cause of their glare and halos,” he said. “If you asked me which one is doing it, the answer is, yes, both of them. We didn’t actually try to quantify glare and halos pre- and post-YAG.”

IOL exchange should not be considered after capsulotomy because of potential complications such as retinal breaks, tears and detachment, Dr. Taravella said.

“I would say the main thing is, don’t YAG a patient until you’re really sure that you’re not going to do a lens exchange,” he said. “I always tell my patients, ‘Once we open up the capsule, you’ve bought the lens. We’re not going to be taking it out.’”

In addition, a surgeon who is considering laser capsulotomy should first rule out residual refractive error, particularly astigmatism, dry eye, macular edema and other pathologies, Dr. Taravella said.

“If you’re not sure, get an OCT to make sure you’re not dealing with macular edema or an epiretinal membrane that might be a cause of dissatisfaction,” he said. “Because if that’s the case, then opening the capsule is not going to help them any and they might benefit from an intraocular lens exchange.” – by Matt Hasson

Reference:

• Shah VC, Russo C, Cannon R, et al. Incidence of Nd:YAG capsulotomy after implantation of AcrySof multifocal and monofocal intraocular lenses: a case controlled study. J Refract Surg. 2010;26(8):565-568.

• Michael J. Taravella, MD, can be reached at 1675 N. Aurora Court, P.O. Box 6510, Mail Stop F731, Aurora, CO 80045-0510; 720-848-2500; fax: 720-848-5014; e-mail: michael.taravella@ucdenver.edu.