| Researchers have found that immediately treating people who
have early stage glaucoma can delay progression of the disease.
This finding supports the medical community's emerging consensus
that treatment to lower pressure inside the eye can slow glaucoma
damage and subsequent vision loss. These results are reported
in the October 2002 issue of Archives of Ophthalmology.
Scientists found that immediate treatment of newly-discovered
primary open-angle glaucoma, the most common form of glaucoma
and one of the nation's leading causes of vision loss, led
to a slower rate of disease progression. The findings from
this study reinforce accumulating medical evidence that lowering
eye pressure in glaucoma's early stages slows progression
of the disease.
"These results strongly support the body of evidence
suggesting that immediate treatment of early stage, open-angle
glaucoma will slow the disease progression," said Paul
Sieving, M.D., Ph.D., director of the National Eye Institute
(NEI), one of the Federal government's National Institutes
of Health and co-sponsor of the study. "Unfortunately,
glaucoma has no early warning signs, and many affected patients
are unaware they have the disease until it has advanced. Once
people have lost vision from glaucoma, it cannot be regained.
However, early detection and timely treatment would help to
save the vision of thousands of people each year."
Dr. Sieving also notes that the study results provide important
new medical knowledge on the course of the disease, both among
treated and untreated patients. "Because most people
are treated for glaucoma as soon as they are diagnosed, little
is known about the natural history of the disease," he
said. "Future reports from the study will add further
important information on glaucoma progression and its risk
factors."
The study -- called the Early Manifest Glaucoma Trial --
followed 255 patients, aged 50-80 years, with early stage
glaucoma in at least one eye. Most patients were identified
in a population screening. The average age of the patients
at the beginning of the study was 68 years. One group (129
patients) was treated immediately with medicines and laser
to lower eye pressure, and the other group (126 patients)
-- the control group -- was left untreated. Both groups were
followed carefully and monitored every three months for early
signs of advancing disease, using indicators that are extremely
sensitive for detecting glaucoma progression. Any patient
in the control group whose glaucoma progressed was immediately
offered treatment.
After six years of follow-up, scientists found that progression
was less frequent in the treated group (45 percent) than in
the control group (62 percent), and occurred significantly
later in treated patients. Treatment effects were also evident
in patients with different characteristics, such as age, initial
eye pressure levels, and degree of glaucoma damage. In the
treated group, eye pressure was lowered by an average of 25
percent.
The study was a collaborative effort involving the University
of Lund, Sweden, with centers in Malmö, Helsingborg,
and Lund, Sweden, as well as Stony Brook University, Stony
Brook, New York.
These results should be put into perspective, according to
Anders Heijl, M.D., Ph.D., chairman of the Department of Ophthalmology
at Sweden's Malmö University Hospital and first author
of the report. "Although the study closely checked for
possible glaucoma progression, many of the patients remained
stable over time, even those in the control group," Dr.
Heijl said. "On the other hand, despite the clear effect
of treatment, glaucoma progressed in as many as 30 percent
of treated patients after four years."
Dr. Heijl said that the time it took for glaucoma to progress
varied greatly among patients and was sometimes rather short,
even in treated patients. "This shows that in many patients
with rapidly progressing glaucoma, the treatment used in this
study was insufficient to halt progression of the disease,"
Dr. Heijl said. Dr. Heijl emphasized that treatment for early,
newly diagnosed glaucoma should be individualized and carefully
balanced. Before deciding on the best treatment option, eye
care professionals should consider several unique patient
factors, such as age, eye pressure levels, and disease severity.
"The study findings support the medical community's growing
contention that glaucoma treatment should be tailored to the
individual needs of the patient," Dr. Heijl said. "One
option could include no initial treatment, but subsequent
treatment if the disease progresses. Many glaucoma medicines
have side effects, so the decision not to treat the disease
in its early stage -- but closely monitor patients -- can
postpone or obviate the need for medications."
Although the study results confirm the belief that reducing
eye pressure is beneficial, "they do not prove that elevated
eye pressure in itself is the primary cause of glaucoma,"
said M. Cristina Leske, M.D., chair of the Department of Preventive
Medicine at Stony Brook University and a study co-author.
"However, because reducing eye pressure slows the progression
of glaucoma, eye pressure levels are important in the course
of the disease."
Dr. Leske said that the study treatment had few side effects.
The most important was an increase in nuclear opacities, a
type of cataract, but the number of related cataract surgeries
in the treated group was small.
Open-angle glaucoma affects about 2.2 million Americans age
40 and over; another two million may have the disease and
don't know it. Glaucoma occurs when the optic nerve is damaged.
In most cases, increased pressure in the eye is a risk factor
for this damage. The damage to the optic nerve causes loss
of peripheral (side) vision, although people are often unaware
that they have glaucoma. As the disease worsens, the field
of vision gradually narrows and blindness can result. However,
if detected early through a comprehensive eye exam, glaucoma
can usually be controlled and serious vision loss prevented.
The Early Manifest Glaucoma Trial was co-sponsored
by the Swedish Research Council.
The National Eye Institute is part of the National Institutes
of Health (NIH) and is the Federal government's lead agency
for vision research that leads to sight-saving treatments
and plays a key role in reducing visual impairment and blindness.
The NIH is an agency of the U.S. Department of Health and
Human Services. October 2002
previous
| next
|
