New drug gives patient his sight back

Hadley Leggett
Published on March 23, 2022

When Gang Pan first came to Stanford Medicine, he could no longer work or drive and was uncomfortable even venturing out in public because an autoimmune condition had severely restricted his vision and the movement of his eyes.

A condition called thyroid eye disease had caused the soft tissue behind his eyes to swell and push one of his eyeballs to point up and the other to point down, rendering him functionally blind.

"I had to cover my eyes to go outside because they were really scary even just to look at," said Pan, who was seen at the multidisciplinary Thyroid Eye Clinic. "As the swelling got worse, it got to the point where I didn't want to go out at all."

In addition to restricting his eyeballs' movement and creating severe double vision, the inflammation also compressed Pan's optic nerves -- which carry images from the eye back to the brain -- affecting his ability to see and discern colors, and threatening permanent blindness.

But in January 2020, Pan became the first patient with sight-threatening thyroid eye disease to be treated with a newly FDA-approved drug called teprotumumab, or Tepezza. After two IV infusions of the drug, Pan regained the ability to move his eyes and see colors and details of objects from afar.

"We were shocked and so excited," said Stanford Medicine assistant professor of ophthalmology Andrea Kossler, MD, who co-led his treatment team. "We did not expect such a dramatic improvement, especially after just two infusions."

Thyroid eye disease: An unpredictable autoimmune disease

Symptoms of thyroid eye disease range from mild complaints like dry eyes or redness to moderate symptoms like bulging eyes and double vision, all the way to the severe symptoms Pan experienced, which can include blindness.

Studies suggest that the disease affects approximately 16 in 100,000 women and 3 in 100,000 men in the United States.  

"Thyroid eye disease is a heterogeneous and unpredictable autoimmune condition," said Kossler.

Prior to 2020, there were no targeted or FDA-approved treatments for thyroid eye disease. Patients with advanced forms of the disease received high doses of steroids or radiation to halt inflammation, but these treatments did not reverse the disfiguring or disabling symptoms already caused. Other patients might have to wait months before becoming eligible for surgery to fix bulging eyeballs, double vision or eyelid changes.