The first drug showing promise of reducing vision loss caused by macular degeneration, which affects 1.7 million Americans 50 or older, was approved Friday by the U.S. Food and Drug Administration.
Lucentis, made by Genentech, was found in clinical trials to stabilize vision in 95 percent of patients. What is most promising, said Fort Wayne retinal surgeon Dr. Gohar Salam, is that 25 percent of patients treated regularly with Lucentis improved their vision by three additional lines on the standard eye exam chart.
“It’s still not a cure, but it’s a significant step forward,” Salam said.
Macular degeneration’s symptoms hit Anneliese Remington, 80, of Fort Wayne quickly. “In March, my great-grandson was ice skating at McMillen Park. When he was done, I tried to get down the bleachers and I could hardly see,” she recalled.
At home she looked at a printed grid on the refrigerator, given to her by her ophthalmologist. The normally straight lines appeared wavy, a key sign of macular degeneration.
“It was so scary,” she said. Her ophthalmologist referred her to Salam, who diagnosed an advanced form of the disease called wet macular degeneration.
Remington’s first treatment, photodynamic therapy, was ineffective, so Salam suggested an experimental treatment, an earlier form of the just-approved drug. “In three to four weeks, I noticed marked improvement,” Remington said. “My right eye is still not as good as the left, but I can see much better and I feel safer behind the wheel.”
Macular degeneration, the most common cause of legal blindness in people over 60, according to the National Institutes of Health, is a progressive disease of the center part, or macula, of the retina of the eye. A person 65 or older today has a one-in-four chance of developing the disease. During the 2000 Census, 25,615 people 65 and older lived in Fort Wayne. As America grays, the disease portends a health and social crisis in the making – by 2020, 6 million Americans could be blind from some form of eye disease.
Macular degeneration causes loss of central vision, making facial recognition, reading and watching movies and television difficult or impossible. Salam describes the retina as the “wallpaper” on the inside of the back of the eye. The light-sensitive retina converts light and images into nerve impulses that travel up the optic nerve to the brain. The brain’s interpretation of the images is how we see.
People with age-related macular degeneration, or AMD, may not notice the subtle hallmark vision changes: vertical objects or lines may be a little off kilter, appearing bent; areas of gray appear in the center when focusing on an object. Peripheral vision remains, so someone with advanced disease may be considered legally blind yet retain a small ring of vision.
Lucentis is a first-line cousin to a cancer drug called Avastin, also made by Genentech.
“Researchers knew Avastin kills new blood vessels in cancer,” Salam said. Abnormal growth of blood vessels is a complication of advanced macular degeneration. Genentech changed the molecule size of Avastin so it could better penetrate the retina when injected into the eye.
Salam, who participated in clinical trials for Avastin while waiting for Lucentis to be approved by the FDA, offered it to patients such as Remington in whom other treatments failed.
Although no treatment exists as yet for advanced, or wet, AMD, drugs such as Lucentis, and its forerunner Macugen, can delay progression of vision loss by AMD. Made by Pfizer, Macugen was FDA-approved in December 2004, and has shown improvement in stabilizing the disease in 70 percent of cases; Lucentis’ rate is 95 percent.
Remington may need additional treatments with Lucentis. For best results, injections every four weeks are prescribed. But Remington, whose condition stabilized after just one injection, may be given Macugen, which is injected every six weeks, or put on a regimen combining both treatments, Salam said.
“It is the scariest thing to lose one’s eyesight,” Remington said, adding that she is glad she agreed to use the drug at a time when it was still in the experimental stage. Possible side effects from Lucentis include eye redness and irritation, with less common side effects of cataracts, infection, retinal tears and detachment. In clinical trials, 4.2 percent to 4.6 percent of patients given Lucentis for two years suffered a stroke or heart attack, compared to 3 percent patients in the control group.
Nevertheless, “These are good breakthroughs,” Salam said. But early detection is still the cornerstone of keeping AMD from robbing vision.
For people who have had routine vision exams during adulthood, beginning at age 55 they should undergo annual exams involving dilation of the eyes by an optometrist or ophthalmologist: “The earlier people come, the better the outcome,” Salam said.
Disease symptoms
The most common form of age-related macular degeneration of the eye is dry AMD (see graphic). One reason the disease may go unnoticed is that it may develop in only one eye, although that is less common. In 10 percent of people with dry AMD, a form called wet AMD develops. Normally straight lines becoming wavy is a symptom of this most severe and advanced form of AMD. Damage to the macula occurs rapidly, and vision loss is greater than in dry AMD. While there is no definite cause, the most significant risk factors for AMD are age and smoking, said Fort Wayne retinal surgeon Dr. Gohar Salam. Other factors include cardiovascular disease, diabetes, high blood pressure and family history of the disease. Women are at greater risk than men, and obesity may also increase risk.
