While the main symptoms of Crohn's disease involve the digestive tract, the condition can also affect other parts of the body, such as the eyes. As eye tissue is similar to the tissue elsewhere in the body, inflammatory diseases can affect it in similar ways.
Crohn's disease is one of the two major types of inflammatory bowel disease (IBD). The other is ulcerative colitis. IBD is an umbrella term for disorders that stem from chronic inflammation of the digestive tract.
Common symptoms of Crohn's disease include cramps, diarrhea, and bloody stool. However, Crohn's disease can also cause symptoms outside the digestive tract. These include skin complications, problems with joints, and eye disorders.
About 10% of people with Crohn's disease have eye-related symptoms or conditions. Due to the sensitivity of the tissues in the eye, symptoms may occur in this part of the body before people notice them in the gut.
In this article, we discuss eye-related disorders that can occur due to Crohn's disease and why they might occur. We also explain how people can treat these conditions and reduce their risk of developing them.
Several different conditions relating to the eye can affect people with Crohn's disease. These conditions include the following:
Episcleritis. There are a number of eye-related conditions that may affect a person with Crohn's disease.
Episcleritis is a common eye-related disorder for those with Crohn's disease. Episcleritis is the inflammation of the episclera, which is the tissue between the outermost layer of the eye and the white part, or sclera, underneath.
Symptoms include:
- tenderness to touch
- watery eyes
- redness
- bright red spots on the sclera
- mild pain
Unlike some other eye-related conditions that people with Crohn's disease may experience, episcleritis does not cause sensitivity to light or blurred vision. It is also less painful than other eye-related conditions.
Scleritis
Scleritis is the inflammation of the sclera.
Symptoms include:
- redness of the eye
- watery eyes
- pain in or around the eye
- burning
- blurry vision
- headaches
- difficulty sleeping
- sensitivity to light
In extreme cases, inflammation can lead to the thinning of the sclera, which also gives the eye its shape.
Uveitis
Uveitis is the inflammation of the uvea — a layer of tissue that includes the iris — just beneath the sclera. Uveitis affects people with Crohn's disease less frequently than scleritis.
This condition is more serious than episcleritis as it can lead to glaucoma or even vision loss if a person does not receive treatment.
Symptoms include:
- sensitivity to light
- blurred vision
- pain
- redness
These symptoms may occur suddenly or develop slowly over time.
Learn more about uveitis, including its symptoms and treatment options, here.
Keratopathy
Keratopathy is a disorder that affects the cornea, the clear outer part of the eye. It often results in blister-like swelling.
Other symptoms include:
- sensitivity to light
- excess of tears or discharge
- irritation
- the feeling that an object has become stuck in the eye
Dry eye
Dry eye, also known as keratoconjunctivitis sicca, occurs when there is a lack of tear production. It can often feel as though sand or another foreign body is in the eye.
Other symptoms include:
- pain
- burning
- redness
- itching
- stinging
Dry eye has many different potential causes, however. If someone with Crohn's experiences dry eye, there could be a different underlying cause behind it.
Scientists do not yet know the exact causes of eye-related symptoms in Crohn's.
However, Crohn's is an inflammatory disease, and the inflammation that typically affects the digestive tract can sometimes occur in other areas of the body.
In addition to the eye problems above, some people with Crohn's may experience eye disorders due to medication that they take for the disease. For instance, the use of corticosteroids over a long period can lead to glaucoma or cataracts.
If a person experiences persistent eye symptoms, they should see a doctor. A doctor will first carry out a visual examination of the eyes.
They may then use a slit lamp, which is a high intensity light and microscope, to examine the eye further. The use of this instrument can help them confirm whether a person has uveitis or keratopathy.
During the examination, the doctor may also apply drops of yellow dye to the eyes to check the cornea for damage.
Episcleritis is very common, and it is often part of the initial Crohn's disease diagnosis. People may need cold compression or steroids to clear the inflammation, although it may also resolve with the treatment of Crohn's disease.
Uveitis is a more serious condition as it could lead to glaucoma and vision loss if a person does not seek treatment. The treatment for this condition is usually a topical or systemic steroid to reduce inflammation. Drugs that dilate the pupil, such as atropine or tropicamide, may provide temporary relief.
As with episcleritis, uveitis may also improve if treatment brings the person's Crohn's disease under control.
Keratopathy does not result in pain or vision loss. As a result, people experiencing it do not typically require treatment.
For dry eye, treatment includes artificial tears or prescription eye drops. There are also several home remedies for dry eye that may help, including applying a warm compress to the eye.
Eye-related symptoms of Crohn's disease often coincide with bowel symptom flare-ups. As a result, the tips for reducing other Crohn's-related problems also apply to the eyes.
These tips include:
- avoiding tobacco and caffeine
- avoiding high fiber foods
- eating smaller, more balanced meals
- limiting dairy products
- drinking plenty of water
- using stress management techniques to limit stress
Nonsteroidal anti-inflammatory drugs, such as ibuprofen, can also cause flare-ups or worsen the symptoms of Crohn's disease. Avoiding these drugs could, therefore, also help with eye-related symptoms.
If a person with Crohn's disease experiences mild pain or fever, they should ask their doctor if acetaminophen would be suitable.
While Crohn's-associated eye conditions can cause discomfort, they can clear up with the treatment and management of Crohn's disease.
Regular check-ups with an eye specialist can help people identify any eye problems early.
Without treatment, some eye symptoms can be serious. If problems with the eyes persist, a person should speak with a doctor. They should also talk to a doctor if they experience any changes in their Crohn's symptoms.