15th International Thyroid Congress, 85th Annual Meeting of the American Thyroid Association:
Graves' Orbitopathy and Surgical Decompression
Presented at the meeting by Peter Dolman, MD
Orbital Surgery in the treatment of Graves’ Orbitopathy was presented by Peter Dolman, MD at the 15th International Thyroid Congress and 85th Annual Meeting of the American Thyroid Association (ITC/ATA) held in Orlando, FL. Dr. Dolman is a Clinical Professor of Oculoplastics and Orbit, and Division Head at The University of British Columbia in Vancouver.
Graves’ disease is a consequence dysthyroidism, and sometimes referred to Graves’ ophthalmopathy or thyroid-associated orbitopathy. The disease has many manifestations and a wide and varied spectrum of clinical presentations. “In my experience, roughly 70% of patients pursue a relatively mild course,” stated Dr. Dolman. These patients (the 70%) are often younger and nonsmokers, with primarily fat centric disease and less targeting of muscles as demonstrated on CT imaging. Eye lid retraction is the most common feature. Dr. Dolman indicated that proptosis is largely from the fast expansion and variable amounts of muscle enlargement, and secondary exposure symptoms and signs—such as sensitivity to light, tearing, foreign body sensation, and grittiness.
The remaining ~30% of Dr. Dolman’s patients are older and smokers, which he pointed out to be more likely to have bilateral disease usually with a family history. “They present on CT scan with thickened muscles; many extraocular muscles being involved. The onset of their clinical features is much more acute and dramatic,” Dr. Dolman explained. When the disease is aggressive, patients may present with congested features. The CT scan may reveal swollen muscles that are congesting the venous drainage out of the orbit creating a hydraulic effect with swelling in the surface of the eye and retina. “As a result of the muscle involvement, secondary effects are scarring of the muscles, which leads to restriction and a very bothersome diplopia. And in a percentage of patients of that group of patients, roughly 15% of patients will develop optic nerve compression, squeezing of the axoplasm around the dural sheath and dropping vision,” commented Dr. Dolman.
The VISA classification is used by many ophthalmologists to categorize disease in four endpoints.1
- V = vision; optic neuropathy or vision-threatening disease is equivalent to a severe form of disease
- I = inflammation or congestion; measures the soft-tissue component
- S = strabismus; double-vision, restricted motility, eyes turned inward or deviation
- A = appearances changes; representative in the broader category of patients (ie, 70% of Dr. Dolman’s patients mentioned earlier)
“It's the progress of the disease that I like to evaluate as a sign of activity rather than focusing just on the soft-tissue signs or the clinical activity score. So when we use this categorization, we look at an interval change either by history or by objective examination that any one of those four parameters might have progressed. The vision and the soft-tissue change, not an absolute value, but a change in value deteriorating, strabismus, or appearance changes is a sign something is deteriorating with the disease,” explained Dr. Dolman.
Timing and Effectiveness of Therapy
Dr. Dolman uses the analogy with his patients that with inflammation and congestion, especially when symptoms and signs are worsening, “That’s like a fire in a house, and that’s the time to bring in the fire brigade to try to put out the flames and settle the disease.” Putting the flames out sooner can help reduce damage to the orbit. When the patient’s condition is stabilized then surgical treatment to restore alignment of the eyes, reduce prominence and adjust eye lids as necessary can be considered.
“There are some exceptions where you might rush into that house while it's on fire during that active, progressive phase, and the exceptions are additional threatening conditions. So if the cornea is breaking down and medicines aren't working, or if there's optic nerve compression and the medicines aren't working, then that's when the surgeon might be brought in as well to try to intervene,” stated Dr. Dolman.
Surgery may be considered when there is a high Clinical Activity Score and no evidence of thyroid eye disease progression; no development of muscle change or optic neuropathy. Furthermore, the patient has been on high-dose steroids and cyclosporine over a long period of time.
After steroid and radiotherapy, when strabismus is progressive, alignment surgery may be performed 6 to 12 months after full medical therapy concludes, and the patient’s measurements are stable.
Orbital Surgery Goal
The goal of surgical intervention is to prevent disease progression. Despite surgical decompression, about 30% of patients monitored with follow-up CT scans demonstrate muscles continue to expand. Dr. Dolman stated, “You can have a very good [surgical] response in vision—restoration of good vision and color vision—and then suddenly it starts deteriorating again.” Meaning, the additional orbital space surgically created doesn’t half an ongoing inflammatory immune process. That is why it may be important to continue with a steroid and/or radiotherapy.
- Potential Complications: Surgical removal of bone superiorly presents a potential risk of cranial crack and subsequent cerebrospinal fluid leak. Other complications include intracranial hemorrhage and relapse of diminished or loss of vision.
Radiotherapy is used increasingly for prevention in high-risk patients. In a retrospective study of patients with thyroid eye disease, orbital radiotherapy with and without steroids was conducted. The radiotherapy group that also received steroids showed significant better results.2