Thyroid Eye Disease Phases

Thyroid Eye Disease (TED) is a serious, potentially vision-threatening condition that can get worse over time, but can be managed with treatment.

When you have TED, your immune system mistakenly attacks the muscle and fat tissue behind your eyes, causing inflammation (redness and swelling) and scar tissue to form.

TED has 2 phases. The first is called the “acute” phase, which you may hear your doctor describe as the “active” phase of TED. The second is called the “chronic” phase, which you may hear your doctor call the “inactive” phase of TED.

When you first develop Thyroid Eye Disease, you may notice changes happening quickly

TED begins with an acute phase, which means that symptoms appear suddenly and often get worse quickly. The inflammation (redness and swelling) and scarring that start to form during this phase can damage your eyes, and cause a number of changes.

You may notice the following appearance and vision changes:

  • Redness
  • Swelling
  • Dry, gritty eyes
  • Eye bulging
  • Double vision
  • Misaligned eyes or eyes that don’t work together
  • Sensitivity to light
  • Eye pain and pressure

The changes caused by TED may also affect your emotions, making you feel anxious or depressed.

Learn more about the symptoms and signs of TED as well as the impact it can have on your emotional well-being.

While the length of the acute phase of TED is different for everyone, it usually lasts between 6 months to 2 years. During this time, symptoms can change or continue to get worse. Ideally, treatment should be given during the acute phase.

Thyroid Eye Disease may slow down over time, but that doesn’t mean it goes away

The acute phase is followed by the chronic phase of TED. You may have heard your doctor refer to this phase as the “inactive” phase of TED. However, that doesn’t mean your condition has gone away. You may still have symptoms during the chronic phase.

Only a TED Eye Specialist can determine which phase of TED you are in, but there are a few signs to watch for that may signal you are entering the chronic phase:

  • Inflammation (swelling) has stopped or slowed
  • Redness has decreased or gone away
  • Eye bulging hasn’t gotten worse

Inflammation that began during the acute phase can cause scar tissue to build up over time. This can cause damage to the eyes, leaving you with ongoing symptoms like eye bulging, eye pain, eye pressure, double vision and misaligned eyes, if not treated.

If left untreated, certain triggers such as smoking or stress may cause TED to flare. Learn more about triggers using the Triggers and Flares Tool.

Early treatment is better, but treatment later in the course of TED may still help

The longer that TED goes untreated, the more likely it is for serious damage to happen to your eyes. While treatment in the acute phase is recommended, it may still help during the chronic phase.

Learn about a treatment option for TED.

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Get treatment for TED as early as possible to prevent further eye damage.