• The Mystery of the Ghostly White Ring

    Mar. 30, 2018

    A woman in Portugal temporarily stumped her doctors with a ghostly white ring that appeared on her cornea. Eventually, doctors identified the cause: a rare inflammatory condition called Cogan's syndrome. The case was reported in the New England Journal of Medicine.

    The 24-year-old had experienced eye redness and light sensitivity on and off for a decade. New changes in her vision prompted her to return to the doctor. The white ring, along with her other symptoms, pointed to interstitial keratitis (inflammation of the layer of the cornea called the stroma) as the diagnosis. But the woman tested negative for the various infections that are frequently the root cause of interstitial keratitis.

    Six months later, she had a new set of symptoms: vertigo, ringing in her ears and hearing loss. The new symptoms—together with what she'd already experienced—made Cogan’s syndrome the most likely culprit. Cogan's syndrome is a rare autoimmune condition that most often affects the eyes and ears. If it's not treated, Cogan's syndrome can lead to deafness, blindness and other serious health complications. Steroid treatment improved the woman's vision, but some of her hearing loss was permanent.

    Other Causes of Light-Colored Rings on the Iris

    Many people develop a light-colored ring around the outside edge of their iris (the colored part of the eye) as they age. It happens when calcium or lipids (fats) accumulate at the border between the iris and white of the eye. When these deposits build up as a part of the normal aging process, it's called arcus senilis. Most of the time, this condition doesn’t cause any problems.

    There is no treatment for arcus senilis and none is needed. However, the condition can be a sign of high cholesterol, so it's a good idea to check with your ophthalmologist if you notice a ring starting to form around your iris. If younger people develop a ring on their iris, they should see an ophthalmologist as soon as possible. It could be a sign of dietary or other health problems.

    Related video: I have a grey ring around my iris. What is this? - Ask an Ophthalmologist