Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Immediate treatment helps delay progression of glaucoma

14.10.2002


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.


tonometer measures pressure inside the eye and is one of several tests necessary to detect glaucoma.
Credit: National Eye Institute, National Institutes of Health



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 followup, 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. A list of EMGT study centers and principal investigators is attached.

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.

Background

Glaucoma is a group of diseases that can lead to damage to the eye’s optic nerve and result in blindness. Open-angle glaucoma, the most common form of glaucoma, is one of the leading causes of blindness in the United States and the number one cause of blindness among African Americans. Glaucoma usually has no early symptoms, and by the time people experience problems with their vision, they usually have lost a significant amount of their sight.

The Early Manifest Glaucoma Trial

Prior to this study, the natural history of glaucoma was not well defined. Researchers did not know how rapidly, if at all, early stage glaucoma would progress if it were not treated initially. Because most eye care professionals immediately treat newly-diagnosed glaucoma by reducing intraocular pressure, the natural progression of the disease (in its untreated state) was not clear. Researchers were also unclear as to how effective treatment was for early stage glaucoma, because they did not know how rapidly the disease would progress without treatment.

This raised a key question: What price, in terms of side effects, inconvenience, and cost, can be considered acceptable when treatment effects are uncertain? To begin answering this question, a randomized study was designed with a control arm in which participants were followed without treatment as long as progression did not occur, thus not exposing study participants to unacceptable risks.

The Early Manifest Glaucoma Trial is the first large, controlled, randomized clinical trial to evaluate the effects of treatment versus no treatment on early stage glaucoma. More specifically, the study compared glaucoma progression in treated (lowering intraocular pressure) versus control patients. The study also determined how much treatment reduced eye pressure, and helped researchers chart the natural history of the disease.

Patient screening began in October 1992 and ended in April 1997. Study participants came from the Swedish cities of Malmö and Helsingborg. The study followed 255 patients, of which 66 percent were women. All patients were between 50-80 years of age, inclusive (average age: 68), and all had early stage glaucoma (open angle glaucoma or normal tension glaucoma) in at least one eye. One group (129 patients) was treated immediately with medicines and laser to lower eye pressure. A second, control group had 126 patients who were 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 followup, scientists found that in the control group, it took an average of 48 months to detect early signs of advancing disease. However, in the treated group, it took an average of 66 months -- 18 months longer -- to detect these early changes. In the treated group, eye pressure was lowered by an average of 25 percent. All the study participants will continue to be followed and regularly monitored.

The information from this clinical trial adds to the scientific knowledge gained from several other glaucoma-related studies supported by the National Eye Institute, including the Ocular Hypertension Treatment Study (www.nei.nih.gov/news/pressreleases/061302.htm ), the Advanced Glaucoma Intervention Study (www.nei.nih.gov/news/pressreleases/pr798.htm), and the Collaborative Initial Glaucoma Treatment Study (www.nei.nih.gov/news/statements/cigts.htm).

International Collaboration

The study is an example of international collaboration between Swedish and U.S. researchers. The National Eye Institute’s co-sponsorship, along with the Swedish Research Council, of this clinical trial allowed for a sufficiently large study to evaluate the research question of whether lower pressure inside the eye can slow glaucoma damage and subsequent vision loss.

The Early Manifest Glaucoma Trial is a collaborative effort that involves a clinical center at the Department of Ophthalmology of Malmö University Hospital at the University of Lund, Sweden, and its Satellite Center in Helsingborg, Sweden; an independent Data Center at the Department of Preventive Medicine, Stony Brook University, Stony Brook, New York; and a Disc Photography Reading Center at the Department of Ophthalmology in Lund at the University of Lund.

Early Manifest Glaucoma Trial Study Centers & Investigators

Clinical Center
Anders Heijl, M.D., Ph.D., Chairman
Bo Bengtsson, M.D., Ph.D.
Boel Bengtsson, Ph.D.
Department of Ophthalmology
Malmö University Hospital
University of Lund
Lund, Sweden
Phone: 46-40-332741

Data Center
M. Cristina Leske, M.D., M.P.H., Chair
Leslie Hyman, Ph.D.
Mohamed Hussein, Ph.D.
Department of Preventive Medicine
Stony Brook University
Stony Brook, NY
Phone: 631-444-1290

Satellite Clinical Center
Kerstin Sjöström, M.D.
Department of Ophthalmology
Helsingborg Hospital
Helsingborg, Sweden

Disc Photography Reading Center
Anders Bergström, M.D.
Department of Ophthalmology
University Hospital of Lund
Lund, Sweden

NEI Representative
Donald Everett, M.A.
National Eye Institute
National Institutes of Health
Rockville, MD
Phone: 301-451-2020


Michael Coogan | EurekAlert!

More articles from Health and Medicine:

nachricht New High-Performance Center Translational Medical Engineering
26.04.2017 | Fraunhofer ITEM

nachricht A promising target for kidney fibrosis
21.04.2017 | Brigham and Women's Hospital

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>