Crohn's disease is an inflammatory bowel disease (IBD) that causes inflammation in the digestive tract and potentially other sensitive areas of the body. Crohn's disease may cause uveitis, keratopathy, dry eye, and episcleritis.
Crohn’s disease is an inflammatory bowel disease (IBD) that causes inflammation in the digestive tract and potentially other sensitive areas of the body. Although IBD is typically linked to symptoms in the digestive tract, people have reported effects of Crohn's disease on their eyes caused by inflammation in one or both eyes.
The effects of Crohn’s disease on your eyes could even appear before any other common side effects, including abdominal pain, severe diarrhea, fatigue, weight loss, and malnutrition. If you are diagnosed with Crohn’s-related eye ailments, you may experience some pain.
While the medical community is yet to determine why Crohn's disease causes eye complications, there is some evidence that IBD may affect other organs beyond the gastrointestinal tract.
Antigens and inflammatory bowel disease
The antigens in your eyes are similar to those in the gastrointestinal system. Antigens can be substances like bacteria, viruses, or chemicals that trigger an immune response in your body. In Crohn's disease, this autoimmune response may also extend to the eyes since they have similar antigens.
Although there are treatments that help reduce symptoms, like those in the eyes, there is no cure for Crohn’s disease. If left untreated, it can cause complications that could be life-altering or life-threatening. In some rare instances, Crohn’s disease may lead to loss of vision.
What leads to Crohn’s-related eye disorders?
There's some evidence that Crohn's disease could be genetic. Another factor that increases the risk of contracting eye symptoms is when you have another extraintestinal expression of IBD. Extraintestinal manifestations (EIMs) are symptoms that are a direct result of Crohn’s disease but occur outside your gastrointestinal tract.
Sometimes it's not the Crohn's disease itself but the medications you are taking that can result in eye symptoms.
Types of Crohn’s-related eye disorders
The four main eye disorders that are attributed to Crohn’s disease are mentioned below. In some exceptional cases, you may get inflammation in other parts of your eyes such as the retina and the optic nerve.
Uveitis is a condition that causes inflammation of the uvea, which is a tissue coating below the white layer of the eye that includes the iris. Although not common, it is a serious condition that, in rare and extreme instances, can cause glaucoma and loss of vision. Common symptoms include:
- Blurred vision
- Pain
- Redness in the eyes
Research indicates that women are more likely to contract uveitis compared to men.
Keratopathy
Keratopathy means "disease of the cornea," and is detected by the presence of grey dots. Keratopathy can occur on its own or as a secondary manifestation of another condition such as scleritis. Common symptoms include:
- Heightened sensitivity to light
- Irritation or watering of the eyes
- Reduced vision
- A feeling like there's a foreign object in your eye
- Pain
The medical term for dry eye is keratoconjunctivitis sicca, which is due to your eyes not releasing enough tears. Common symptoms include:
- Burning or piercing sensation
- Itching
- Redness
- Pain
Episcleritis
The episclera is the tissue between the cornea and the white layer of your eye. Episcleritis is the inflammation of this tissue layer. This is the most commonly reported eye disorder for individuals with Crohn’s disease. It causes less pain compared to uveitis, and does not lead to blurred vision or sensitivity to light. Some of the symptoms are:
- Redness of the eyes
- A fragile feeling when you touch your eyes
- Watery eyes
How to identify Crohn’s disease in the eyes
Your ophthalmologist will quickly check your medical history and examine your eyes to make an informed diagnosis. Uveitis and keratopathy can be diagnosed by examination with a slit lamp (a type of microscope also called an ophthalmoscope). Doctors may apply drops containing a yellow dye (fluorescein) that makes examining the cornea easier.
The combination of the light from the ophthalmoscope and the dye will help detect any irregularities or lesions on your cornea. This helps your ophthalmologist to understand the extent of damage, if any, and suggest possible treatments.
How to treat Crohn’s-related eye disorders
Episcleritis may get treated along with your treatment for Crohn’s.
If the treatment prescribed for Crohn’s doesn’t help clear it up, you may be prescribed drugs like tropicamide and atropine to offer short-term relief. Your doctor may also recommend cold compresses and topical steroids.
If you have uveitis, timely treatment is critical. This is because it can lead to glaucoma and loss of vision if left untreated.
For keratopathy, doctors usually treat with lubricating fluids and gels or prescribe medicated eye drops for more serious cases.
When it comes to the treatment of dry eyes, doctors usually use anti-inflammatory agents, with topical cyclosporine being the most effective. Recent evidence suggests that anti-inflammatory treatments slow down the production of inflammatory mediators and help with the healing process.
When to see a doctor
Around 6% of individuals with IBD report extraintestinal disorders; about half of those have uveitis.
Most eye-related conditions are relatively easy to treat if they are diagnosed early. Scheduling regular eye check-ups with your eye doctor can help you detect symptoms early. If you’ve been diagnosed with Crohn’s disease and feel pain or unexpected symptoms in other parts of your body, including your eyes, contact your doctor immediately.