The study appears in the September issue of Ophthalmology, the journal of the American Academy of Ophthalmology.
"The effectiveness of this treatment, which has been widely used for 80 years, has never been convincingly established," says Colum Gorman, M.D., Ph. D., a Mayo Clinic endocrinologist and specialist in Graves’ disease.
The researchers designed the study so that neither the patient nor those who appraised the treatment response via extremely precise measurements knew which eye had been treated. They learned that there was no difference between treated and untreated eyes after either three or six months. The researchers then studied whether treatment earlier or six months later in the course of the disease made a difference, and they found none.
"Because this treatment is still in wide use, is expensive and is not without risk, it is our belief that it should not be used for patients with mild or moderately severe ophthalmopathy," says Dr. Gorman.
The researchers did not study patients with very severe ophthalmopathy that has damaged the optic nerve. Thus, they have no data on the effectiveness of orbital radiotherapy for those patients.
"It is important to understand the entire disease process and how it affects the whole person," says Dr. Gorman. "Graves’ disease is a naturally remitting condition, and over a period of time many of the symptoms, including the eyes, may improve. It is our belief that this tendency to natural remission, together with the imprecision of measurements used in most previous studies, has allowed the perception to persist that the treatment is effective."
As patients with Graves’ ophthalmopathy decide on what treatment is best for them, Dr. Gorman emphasizes the importance of developing a coordinated approach in which the patient, an endocrinologist and ophthalmologist work together as a team to define the best action plan. Other forms of readily available treatment include the use of oral corticosteroids, orbital decompression, eye muscle surgery and eyelid surgery.
Graves’ disease is a form of hyperthyroidism in which too much thyroid hormone is present in the body, causing an increase in the body’s metabolism. Graves’ disease most often affects women between the ages of 20 to 60 years. With modern treatment, it is not considered life-threatening. Graves’ ophthalmopathy is less common, causing problems in approximately three to five percent of the persons who are diagnosed with Graves’ disease. Graves’ ophthalmopathy is characterized by bulging eyes or red and swollen eyes; excessive tearing; widening of the space between upper and lower eyelids; and light sensitivity, blurry or double vision, inflammation or restricted eye movements.
Lisa Copeland
507-284-5005 (days)
507-284-2511 (evenings)
e-mail: newsbureau@mayo.edu
Journal
Ophthalmology