Pacific Vision Foundation was founded in 1977 with the mission to prevent blindness and to improve vision for those who see imperfectly by fostering the highest level of eye care for the public. This is to be accomplished through contributing to excellence in patient care, improving eye care education of both medical professionals and the public, and supporting innovative ophthalmic research.
San Francisco: July 10, 2015 - Thyroid eye disease (TED), also known as Graves’ dysthyroid ophthalmopathy (GDO) or Graves’ disease is an inflammatory autoimmune disorder. Symptoms may include visual decline, double vision, protrusion of the eyes, ocular dryness, light sensitivity, and eyelid retraction. Women are six times more likely than men to suffer from GDO. It most often strikes people in the prime of life, between the ages of 20 and 50, and 94% of cases are associated with hyperthyroidism. Patients report emotional lability, depression and difficulty concentrating. There have been no anatomic studies to date evaluating these cognitive concerns.
Dr. Rona Z. Silkiss, Chief of CPMC’s Division of Ophthalmic Plastic, Reconstructive and Orbital Surgery, leveraged her more than two decades of experience treating GDO to spearhead an innovative study evaluating the cognitive and emotional manifestations of GDO. Her research, funded by a grant from PVF, analyzed the distribution of cortical changes associated with GDO with MRI—a critical step in understanding the origins and mechanism of psychological change in these patients. Though previous research had identified metabolic abnormalities in the prefrontal and limbic system of GDO patients, there is little understanding of the link between GDO, stress and neurological dysfunction. In particular, there had been no full-brain anatomical or magnetic resonance imaging (MRI) evaluations identifying specific brain areas that are affected by the disease. Dr. Silkiss’ study is the first to use MRI technology to quantitatively investigate the cortical correlates in GDO.
Specifically, Dr. Silkiss and her research team performed structural MRI scans on 10 GDO patients and 10 age-matched control subjects. They measured changes in gray matter thickness in the brain regions that are typically associated with neuropsychiatric disorders. The researchers compared the cortical thickness in GDO patients to controls. Serum analysis of thyroid function tests and antithyroid antibodies were performed as well.
As Dr. Silkiss explained, “Neurologic research has demonstrated that long-term psychiatric illness and overall cognitive performance are closely associated with gray matter thickness decreases in well-defined cortical regions. Understanding the functional and anatomic impact of hormonal changes, stress, inflammatory and autoimmune disease on the central nervous system is interesting and important. Our study looked for changes in the cortices of patients with thyroid eye disease, and compared these changes to normals as well as those observed in individuals with neuropsychiatric impairment. By comparing our data to studies of patients with depression and executive decision making dysfunction, we were able to identify how closely the cortical findings and cognitive symptoms of thyroid eye disease mirror those of known neuropsychiatric disease. Understanding the neuropsychological consequences of thyroid eye disease may enable us to treat this condition more effectively.”
The study’s results showed that GDO patients had statistically significant thinning of the gray matter sheet in at least six locations, mostly in the right brain hemisphere. Compared to the control group, average gray matter thickness levels in GDO patients decreased by 0.5 to 0.9 mm, with variations in different brain areas. These gray matter thickness decreases may well be linked to the impairments in cognition and emotional regulation reported by GDO patients.
Dr. Silkiss’ findings could yield valuable information regarding the association of thyroid hormone abnormalities and thyroid eye disease with neurophysiologic symptoms. Ultimately, a more comprehensive scientific understanding of these effects could revolutionize medical concepts of the etiology of thyroid eye disease while significantly improving treatment and prevention interventions. The study’s results have been submitted to the prestigious American Ophthalmology Society, which was founded in 1864 as the first medical specialty society in the U.S.
Dr. Silkiss and her colleagues believe that their study is the first to demonstrate that GDO, a disease normally correlated with ophthalmologic signs and symptoms, is also associated with changes in cortical thickness in parts of the brain known to regulate emotional state and metacognition. “Recognizing and understanding the anatomic correlates of the cognitive deficits associated with GDO will help clinicians properly diagnose and treat the disease,” she said. “The discovery that these cognitive deficiencies have a neuroanatomical basis is a significant step toward realizing this goal.”
EDITOR’S NOTE – The report originally published in the Spring issue of PVF’s Horizon Newsletter regarding this research conducted by Dr. Silkiss contained several scientific misstatements, which have been corrected and updated in the release above.
Pacific Vision Foundation is a 501(c) 3 organization, founded in 1977 with the mission to prevent blindness and to improve vision for those who see imperfectly by fostering the highest level of eye care for the public through contributing to excellence in patient care, improving eye care education of both medical professionals and the public and supporting innovative ophthalmic research. PVF has supported the Ophthalmology Residency program at CPMC since its inception.
PVF is located at 711 Van Ness Avenue in San Francisco. www.pacificvisionfoundation.org
For additional information please contact
Jo Burnett at (415) 393-1225.