When a certain receptor in eye cells gets turned on, it triggers processes that cause the cells to release a gooey substance, leading to eye bulging and swelling in people with thyroid eye disease.

Some new treatments for thyroid eye disease might work better by hitting two different pathways in the eye that cause swelling, instead of just one.

In eye cells from people with a thyroid eye disease, a lab-made version of a hormone turns on a cellular signal but doesn't trigger the production of a gooey substance that causes swelling — meaning the signal doesn't always lead to the swelling effect.

In most people with a thyroid eye problem called Graves' ophthalmopathy, certain immune proteins seem to make eye cells produce a gooey substance, and they do it using backup routes instead of the main one scientists expected.