New Drug Slows Wet Macular Degeneration
Experiemntal Treatment Prevents Vision Loss, Slows Disease Growth
Aug. 21, 2003 -- An experimental new drug may save the eyesight
of older adults who suffer from a vision-robbing disease known as wet macular
degeneration, according to new research.
Macular degeneration is the leading cause of legal blindness
and vision impairment among adults over 60 and is also known as age-related
macular degeneration (AMD) because it primarily affects older adults.
Although the "wet" form of the disease only accounts
for about 10%-15% of all macular degeneration cases, it is responsible for 90%
of blindness caused by the condition. The wet form is more severe and more
About 250,000 new cases of wet macular degeneration are
diagnosed each year. Although the cause is unknown, the condition results in an
abnormal growth of leaky blood vessels underneath the macula, which is at the
center of the light-filtering layer known as the retina. The buildup of fluid
in the eye causes vision to become distorted or impaired and can lead to
permanent loss of vision or blindness.
Symptoms include blurred or fuzzy vision, straight lines
appearing wavy, blind spots, difficulty seeing distant objects, and a decreased
ability to distinguish colors.
In a study presented this week at the American Society of
Retina Specialists Annual Meeting, researchers say an investigational new drug
called Retaane prevented vision loss and further disease progression after two
years of treatment in a group of patients with wet macular degeneration.
Experimental Drug Shows Promise
Researchers say the drug, which is not yet approved by the FDA,
works by slowing or stopping the growth of new blood vessels to reduce leakage
and prevent damage to the retina.
In the study, 73% of the patients treated with Retaane had
stable or improved vision after two years of treatment compared with 47% who
experienced similar results on the placebo.
The men and women averaged 77 years of age, and 55 of the
original 128 patients with wet macular degeneration completed the two-year
clinical trial of the drug.
During the study, patients were randomly assigned to receive
one of three dosages of Retaane or a placebo once every six months. The drug
was given to patients during a procedure at the doctor's office in which a
specially designed tool is used to deliver the drug directly behind the macula
in the eye.
More Study Planned
Researcher Henry L. Hudson, MD, an ophthalmologist at the
Retina Centers, P.C. in Tucson, Ariz., says these findings confirm earlier
results from a one-year study and show Retaane provides long-term benefits to
people with wet macular degeneration.
The drug's manufacturer, Alcon, says it is launching a phase
III clinical trial to compare the effectiveness of Retaane vs. photodynamic
therapy using Visudyne, which is the current standard of treatment for wet
macular degeneration, at more than 50 sites in the U.S., Canada, Europe, and
Once those results are in, the company can then apply for
approval for use in treating wet macular degeneration from the FDA.