All About Cataracts

Implantation of a popular multifocal intraocular lens (IOL) during cataract surgery provides clear and stable visual acuity — both for distance vision tasks such as driving and for near vision tasks such as computer work and reading.

Tecnis Multifocal IOL (Image: Abbott Medical Optics)

That’s the finding of a new study published this month in Journal of Cataract & Refractive Surgery.

Researchers in Japan conducted a retrospective study of 72 eyes (of 41 patients) that were implanted with the Array Multifocal IOL (Abbott Medical Optics, Santa Ana, Calif.) after cataract extraction.

The mean age of patients in the study was 48.7 years (range: 18 to 71 years) and all participants were followed for a period of four years after surgery.

Among the results:

• At one month after surgery, mean uncorrected distance visual acuity (VA) was between 20/20 and 20/25, and mean uncorrected near VA was between 20/30 and 20/40.
• Visual acuity remained stable for the four-year study period, but patient satisfaction with near vision decreased at two years after surgery.
• A follow-up laser eye surgery — laser capsulotomy — was performed on 48 eyes (66.7 percent) due to formation of posterior capsular opacification (PCO).

PCO is a clouding of the posterior portion of the lens capsule — the normally clear sac-like structure that holds the eye’s natural lens in place — that is intentionally left in place during cataract removal to prevent certain cataract surgery complications.

Laser capsulotomy is a brief outpatient procedure that uses a special laser (called an Nd:YAG laser) to create a central opening in the lens capsule to restore vision.

The mean time for laser capsulotomy surgery was approximately two years after cataract surgery.

The researchers concluded that the Array Multifocal IOL provided good and stable distance and near visual acuities over the four-year follow-up, despite a significant percentage of eyes receiving the lens implant experiencing posterior capsule opacification that affected near vision and required subsequent surgical treatment.

Ed. note: The Array Multifocal IOL, which was the first FDA-approved multifocal IOL, is no longer available. Abbott Medical Optics has replaced the Array IOL with two new multifocal IOLs: the ReZoom and Tecnis Multifocal IOL. Ask your cataract surgeon for details.

People who have cataract surgery before age 65 appear to have a greater risk of clouding of the eye tissue directly behind the intraocular lens (IOL) that can lead to vision loss, according to a Swedish study.

The good news is that vision loss from this cataract surgery complication — called a posterior capsule opacity (PCO) — usually can be restored with a simple laser procedure called a ND:YAG laser capsulotomy.

Researchers at Norrlands University Hospital in Umea, Sweden, compared the vision of 116 patients who had cataract surgery prior to age 65 with the post-operative vision of patients age 65 and older at the time of surgery. Ten years after cataract surgery, 102 of the 116 people in the study group were given an eye exam and were asked to complete a questionnaire about their vision.

Analysis of the data revealed that within 10 years of cataract surgery, 37 percent of those younger than age 65 at the time of surgery experienced PCO and underwent a ND:YAG laser capsulotomy to restore their vision. In comparison, only 20 percent of those who were 65 or older at the time of cataract surgery required the laser procedure afterward.

The researchers concluded that more than one-third of patients in this study who were under age 65 at the time of cataract surgery subsequently developed a posterior capsule opacity that required a laser capsulotomy to restore vision.

Secondarily, the researchers said that 10 years after surgery, subjective visual function (measured with a questionnaire) and objective visual acuity (measured with an eye chart) remained stable in most patients who had cataract surgery when they are younger than age 65.

SOURCE: Ten-year longitudinal vision function and ND:YAG laser capsulotomy rates in patients less than 65 years at cataract surgery. American Journal of Ophthalmology. Published online November 18, 2009.