Actor Lee Dong Gun Diagnosed With Rare Incurable Disease Affecting Only 1% of Koreans

The latest episode of SBS‘s My Little Old Boy revealed actor Lee Dong Gun‘s diagnosis that left his mother and fans completely brokenhearted.

Lee Dong Gun was spotted visiting the hospital with severe redness in his right eye. In the consultation room, the actor told his doctor that when the symptoms are severe, “the redness gets much worse and [he becomes] extremely sensitive to light.”

When it’s not too bad, my eye just gets red, and my focus is a little off. When it’s severe, the redness gets much worse, and I become extremely sensitive to light. Seeing light is painful, and I feel my vision deteriorating. After dealing with it for a year, I’ve gotten somewhat used to it, but at first it was terrifying.

— Lee Dong Gun

After examining Lee Dong Gun’s X-rays, the doctor diagnosed his condition as ankylosing spondylitis (AS), a rare inflammatory disease.

You have uveitis right now. If uveitis keeps recurring, it could be a type of rheumatic disease known as ankylosing spondylitis. It’s a rare illness that affects about 1% of Korea’s population, causing the spine to gradually stiffen and fuse. Most ankylosing spondylitis patients experience uveitis as their first symptom.

If we classify your X-rays by arthritis stages, your inflammation is around stages 2 to 3. Based on the recurrent uveitis and inflammation in the sacroiliac joint, ankylosing spondylitis can be diagnosed.

— Doctor

In addition, the doctor mentioned that “there’s a specific gene” linked to the disease—which Lee Dong Gun was surprised to hear, since no one else in his family had shown any symptoms. Explaining that in 1–2% of cases, the condition can occur as a rare, isolated case like his, Lee Dong Gun’s doctor stressed the importance of lifestyle management.

In your current state, the disease could worsen. Since the cause is unknown and there is no complete cure, it’s a condition that must be managed for life.

— Doctor

Amid the news, some viewers have voiced concern about whether the disease could be hereditary for Lee Dong Gun’s daughter, Lee Ro Ah. Lee Ro Ah was born in 2017 between him and his actress ex-wife Jo Yoon Hee. Others have noted, “Lee Dong Gun’s case seems to be a rare one,” cautioning against overinterpretation.