All About Cataracts

Researchers in Canada have found that expedited cataract surgery among older patients improves visual acuity but does not appear to significantly reduce the risk of falls among this population.

The investigators conducted a systematic review of several studies that evaluated the effect of surgical removal of cataracts shortly after they were discovered as a measure to improve vision and reduce the risk of injury among older adults. Both published and unpublished studies dating from 1950 to 2008 were included in the research.

Vision data from 737 patients were included in the analysis. Analysis of the data showed that expedited cataract surgery significantly improved visual acuity in most cases. But analysis of pooled data from 535 patients showed only a nonsignificant reduction of falls after cataract surgery.

The researchers concluded that accumulating evidence indicates expedited cataract surgery is effective in significantly enhancing vision but is inconclusive in preventing falls.

The full report of the research appears in this month’s issue of Journal of Cataract and Refractive Surgery.

The results of the study are contrary to research reported in the April 2007 issue of the Canadian Medical Association Journal (CMAJ),* which found evidence that vision and quality of life decrease, and the rate of falls increases, among patients during the waiting period for cataract surgery.

*The consequences of waiting for cataract surgery: a systematic review. CMAJ. Vol 176, No 9. April 24, 2007.

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.

The use of premium intraocular lenses (IOLs) in cataract surgery performed in the United States is increasing, according to recent surveys.

Premium IOLs include multifocal lens implants and accommodating IOLs. Both types of presbyopia-correcting intraocular lenses give patients a broader range of vision, reducing or eliminating the need for reading glasses after cataract surgery.

According to a recent survey of cataract and refractive surgeons reported by the eyecare industry research firm Market Scope, 71 percent of U.S. eye surgeons offered their patients the option of premium IOLs in 2008, up from approximately 59 percent in 2007. The company also estimates that 210,000 presbyopia-correcting IOLs were implanted during cataract surgery or other vision correction procedures in the U.S. in 2008, up from 153,000 in 2007.

Eye surgeons also say they prefer premium IOLs for the correction of high myopia. In a 2008 member survey of the American Society of Cataract and Refractive Surgery (ASCRS) more eye surgeons responding to the survey reported preferring premium IOLs (40 percent) to LASIK (23 percent) for the correction of large amounts of nearsightedness in patients desiring elective refractive surgery.

Among ASCRS surgeons using presbyopia-correcting premium IOLs, their top three lens choices in 2008 were the AcrySof ReSTOR multifocal IOL (Alcon), the Crystalens accommodating IOL (Bausch & Lomb) and the ReZoom Multifocal IOL (Abbott Medical Optics).

Other premium intraocular lenses include toric IOLs that correct astigmatism and aspheric IOLs designed to reduce glare and improve night vision.

Premium IOLs cost more than standard IOLs, and the added expense of these lenses typically is not covered by vision insurance and must be paid out-of-pocket, increasing your cataract surgery cost. However, most people who choose premium IOLs are very pleased with the added visual benefits the lenses provide, according to eye surgeons who offer them.

Most people undergoing cataract surgery with implantation of a multifocal intraocular lens (IOL) require approximately six months to fully adapt to the IOL and achieve maximum visual benefit, according to new research from Spain.

Researchers at Hospital Quiron in Madrid evaluated the visual performance of patients receiving the Tecnis Multifocal IOL (Abbott Medical Optics, Santa Ana, Calif.) over time after their cataract surgery. A total of 250 eyes of 137 patients received the multifocal IOL, and patients were evaluated at intervals of one to three days, 30 to 90 days and 150 to 210 days after surgery.

Results of the study revealed that the patients demonstrated a significant improvement in uncorrected and spectacle-corrected visual acuity at both distance and near over the course of the seven-month study period.

At the last follow-up visit (roughly six months after surgery), eye chart testing of the visual acuity (VA) of eyes receiving the multifocal IOL revealed:

• 77.6 percent had uncorrected distance VA of 20/30 or better.
• 98.4 percent had best spectacle-corrected distance VA of 20/30 or better.
• 96.8 percent had uncorrected near VA of 20/25 or better.

More than 90 percent of the patients rated their near, distance and overall vision as good or excellent, and 88.4 percent of the patients did not wear eyeglasses or reading glasses.

Over the course of the study, most patients experienced an improvement in their visual acuity at all distances and a decrease in the intensity of glare and other undesired visual phenomena.

The researchers concluded that the Tecnis Multifocal IOL provides excellent uncorrected near vision and good distance vision when used to treat cataracts. Most patients, however, required an adaptation period of approximately six months to experience the full visual benefits of the lens, they said.

You can learn more about the Tecnis Multifocal IOL by visiting this Abbott Medical Optics website.