What is Coat’s Disease?

What Is It?

Coats’ disease is a very rare eye disorder where blood vessels develop abnormally in the retina. The retina is the part of the eye that transmits light images to the brain. In people with Coats’, blood vessels break open and leak fluid into the back of the eye. As fluid accumulates, the retina becomes damaged and vision worsens. Leaky fluid can also pile up beneath the retina and cause a retinal detachment, where the retina separates from the back of the eye.

Coats’ disease is far more common in boys than girls. Most cases are diagnosed in children before age 10. Because one of the child’s eyes is working normally, they rarely raise a red flag. Early detection and treatment is key to saving vision.

“I like to reassure parents that Coats’ almost always affects only one eye. In the majority of cases, the other eye is normal and has good vision,” said Thomas Lee, MD and chief of ophthalmology at Children’s Hospital Los Angeles. “Because of that, the child will likely lead a very normal life, especially if they wear glasses to help protect the good eye,” 

Signs and Symptoms

Coats’ disease can be easy to miss because children rarely complain about vision changes. The most common sign of Coats’ is a pupil that looks yellow or white (rather than dark or red) when light is shined into the eye. You may notice this as a “glow” in photos of the child taken with flash. Other signals may include:

·      Loss of vision

·      Eye turning outward or inward (strabismus)

Maggie remembers the first time she noticed a ‘glow’ in her 3-year-old son Cameron’s eye. She was in a dimly lit room giving him a bath. Over the next few days she saw that same glow again. Her mother’s intuition told her this must be a sign of something more. Read Cameron’s story.

If you notice any of these signs, schedule a comprehensive eye exam with an ophthalmologist right away. These symptoms can also be warnings of other vision-threatening problems. 

“The sooner we can intervene, the better the prognosis,” said Dr. Lee. “Coats’ often affects peripheral vision first. If we can treat the affected eye before damage progresses to the child’s central vision, we have a better chance of restoring and maintaining sight.”


An ophthalmologist will do a complete, dilated eye exam and refer you to a retinal specialist if they suspect Coats’. The specialist will need to look directly at the retinal blood vessels to make a diagnosis. Your doctor may use a safe, drinkable dye and special camera to pinpoint what’s happening inside the blood vessels. They may also use a special technique called optical coherence tomography (OCT) to capture high-resolution images of the retina. 


There is no cure for Coats’ disease, but progression of the disease can be stopped or stabilized. Treatment depends on the stage of Coats disease when it is diagnosed, and whether retinal detachment has occurred. It may include:

  • Anti-vascular endothelial growth factor (Anti-VEGF) treatment used to prevent or reduce the formation of new leaky blood vessels and lower inflammation.
  • Cryotherapy or extreme cold used to “freeze” and stop abnormal blood vessels from leaking. 
  • Laser therapy/photocoagulation used to shrink or destroy abnormal blood vessels. 

“Laser treatment remains the definitive gold standard treatment for Coats’,” said Dr. Lee.

Treatments may need to be repeated multiple times before the eye is stable. The child will likely need close monitoring for several years and continued follow-up with an ophthalmologist.