Multicenter study finds AMD patients can benefit from cataract surgery

American Academy of OphthalmologyNov 2 2009

This month's Ophthalmology, the journal of the American Academy of Ophthalmology (Academy) reports on a national study that finds cataract surgery is likely to benefit patients with age-related macular degeneration (AMD) at all stages of the disease, on a clinical trial showing that the steroid triamcinolone may be effective in advanced diabetic macular edema (DME) patients when standard treatment fails, and on the public's use of two Academy-sponsored online eye health forums.

Cataract surgery improved vision in patients with any stage-from mild to advanced- AMD in the first study to include an adequate number of advanced AMD patients. Data was obtained from the multicenter, prospective Age-Related Eye Disease Study (AREDS), funded by the National Eye Institute (NEI), which was organized primarily to evaluate the effects of high-dose vitamin and mineral supplements on cataract and AMD. As the American population ages AMD prevalence is expected to rise, and many patients will concurrently develop cataract; both diseases can cause blindness if untreated.

"Earlier epidemiology had suggested cataract surgery might worsen AMD, so the data from the AREDS cohort study were evaluated to answer this important question," said Emily Y. Chew, MD, who led the study for NEI.

The cohort, comprising 1,939 eyes (1,244 patients) with various stages of AMD, was evaluated for visual acuity (sharpness) after cataract surgery. On average, patients with AMD, ranging from mild to advanced, gained visual acuity after cataract surgery; the best gains were in patients with vision worse than20/40 before surgery. No difference in improvement was noted between patients with "wet" (neovascular) or "dry" (central geographic atrophy) AMD. About one year later vision gains remained statistically significant in the 865 eyes available for follow-up. Results for the primary focus of AREDS, regarding the effect of nutritional supplements, showed that high doses of vitamins C, E and beta-carotene did not affect the development or progression of cataract, but this vitamin combination plus zinc did reduce the risk of progression to advanced AMD by 25 percent in the five years of the study.

A five-year study based at the University of Sydney, Australia, found that intravitreal triamcinolone (IVTA) effectively improved vision in patients with DME, a form of diabetic retinopathy, whose eyes had continued to deteriorate despite receiving standard laser treatment.

"The majority of patients who improved with IVTA after initial treatment continued to enjoy better vision at the five year conclusion of our clinical trial, and no new safety concerns were found in these patients," said lead researcher Mark Gillies, PhD. "We believe treatment with IVTA may be considered in carefully selected advanced DME patients when standard treatment has failed to improve vision," he added.

In the first three months after treatment, the patients initially treated with both IVTA and laser showed significantly better gains in vision than control group patients, who were treated with laser only. After two years, patients in the original control group were also treated with IVTA. The beneficial effects persisted in most IVTA-treated patients throughout the five-year study; however, 80 percent of patients in the initial IVTA group developed elevated intraocular pressure and 56 percent of them required glaucoma therapy. Also, two-thirds of all patients required cataract surgery during the study period. Similar outcomes have been noted in other studies of steroid-based treatment and thus were not considered new safety concerns by Dr. Gillies' group.

To identify the topics of highest interest to people who access eye health information on line, John C. Hagan, MD, and colleagues analyzed 4,485 questions over six months (September 1, 2008 to March 1, 2009) posted on the "Ask a Doctor: Ophthalmology" and "Eye Care Community" forums sponsored by the Academy on MedHelp (www.medhelp.org ), one of the 10 largest health information websites. Dr. Hagan and three other ophthalmologists provide free, timely advice to a large and growing number of people with eye health and vision problems through these forums. Serious problems, such as life-threatening retinoblastomas in babies, have been caught and treated in time thanks to these forums, as have thousands of other eye and vision problems.

Concerns related to the retina topped the list at nearly 20 percent of all questions; many people asked about "flashes," "floaters," or retinal detachment. About 19 percent of questions were related to the cornea, the clear outer surface of the eye that helps focus light to make vision possible. Cataract and implanted lens questions were next in prevalence, followed by brain-eye problems (neuro-ophthalmology), children's eye alignment (strabismus), eye cancers, and general discomfort or blurry vision. Two-to-three percent of questions related to each of three vision correction topics: refractive surgery (LASIK and others), eyeglasses, or contact lenses. A smaller number were related to eye care products or medical insurance. The analysis also found many people submit postings to express their gratitude for the medical advice provided.