Her swollen eyes made her see the world in Only 2D

Medical Mysteries Medical Mysteries is a series that spotlights rare diseases or unusual conditions.

- Judith Tan

In September 2022, Madam Goh Sock Cheng started seeing things around her in two-dimensional form, or 2D.

When in a crowd of people, for example, she could not perceive depth. And when she walked into a shopping mall or supermarket where the lights were bright, her vision became a mess, she said.

"I forgot what 3D looked like after a while," added the palliative nurse. "It was not the usual way of looking at things any more. It was very confusing and very glaring. Sometimes I would use just one eye to look at an area before I headed there."

Madam Goh, now 62, had thyroid eye disease (TED), a rare autoimmune disease in which the eye muscles and fatty tissue behind the eyes become inflamed, pushing the eyes forward or causing the eyes and eyelids to become red and swollen.

In some individuals, the eyes end up being out of line, leading to double vision. In rare cases, TED can cause blindness from pressure on the nerve in the back of the eye or ulcers that form on the front of the eye.

The incidence rate of TED is approximately 19 out of 100,000 people a year globally. In Singapore, according to the National University Hospital (NUH), TED has a prevalence of 1 per cent to 2 per cent in the population, or an annual incidence of between 30 and 50 cases per 100,000 people.

Despite having the word "thyroid" in its name, about 30 per cent of TED patients do not have any thyroid disease but still developed TED, said Adjunct Associate Professor Gangadhara Sundar, a senior consultant with the Department of Ophthalmology at NUH.

That is one reason why the condition usually gets misdiagnosed as allergic conjunctivitis or dry eyes.