Eye problems caused by an inflammatory bowel disease (IBD) like Crohn’s disease are divided in two categories: primary and secondary. Primary vision complications appear in tandem with Crohn's and resolve when Crohn's is treated. Secondary vision complications are caused by the primary vision complications or by the methods used to treat the primary vision complications.

Uveitis is one of the most common complications of IBD. It happens when the middle layer of the eye — the uvea — gets red and swollen. Symptoms can include pain, redness, sensitivity to light, blurry vision, or seeing floaters. Although eye drops with steroids reduce some symptoms, uveitis will go away when the IBD is under control. If uveitis is not treated, it can lead to a more serious disease called glaucoma.

Glaucoma may occur as a result of untreated uveitis in people who have Crohn’s disease. Glaucoma develops when fluid builds up in the front of the eye and puts pressure on the eye, which damages the nerve at the back of the eye that connects to the brain. There is no cure for glaucoma, and sometimes there are no signs or symptoms in the early stages. However, if glaucoma progresses, there can be pain, redness, or blurry vision in the eyes. Medications and surgeries are designed to decrease eye pressure.

Scleritis is painful swelling of the white part of the eye known as the sclera. Symptoms can include pain and swelling in other parts of the face or head, blurry vision, tearing, sensitivity to light, and possibly vision loss. Treating Crohn’s disease will control symptoms, but drugs or antibiotics can help with pain and inflammation.

Scleromalacia is a rare form of scleritis. People who have scleritis as a result of Crohn’s disease may also develop scleromalacia, which is a thinning of the sclera — the white outer layer of the eye. Signs and symptoms may also include severe pain, decreased vision, a bulging eye, or even retinal detachment. There are medical therapies that treat scleromalacia. However, because scleromalacia can cause vision loss or the complete loss of the eye, graft surgery may be necessary.

Keratopathy is diagnosed when a person has calcium deposits on the cornea — the clear protective layer of the eye — that form an opaque layer over the cornea. It is not painful nor does it lead to vision loss. People with Crohn’s disease may develop keratopathy as a result of IBD or as a result of scleritis. Keratopathy usually resolves on its own as Crohn’s disease is treated.

Episcleritis occurs when the outer layer of the white of the eye — the episclera — is inflamed. Symptoms can present as pain, tenderness, or discharge. Episcleritis resolves on its own when Crohn’s disease is treated, but the symptoms can be treated with steroid eye drops and other topical medicines.

A cataract is the clouding of the eye’s lens. Most cataracts are age-related and develop gradually, but people with Crohn’s disease can develop cataracts as a result of taking oral steroids to treat their Crohn’s disease. This is called secondary cataract. Common symptoms of cataracts are cloudy vision, faded colors, glare, poor night vision, and double vision. In the early stages of cataract, special eyeglasses can improve vision. If that doesn’t work, the cataract may have to be surgically removed.

People with Crohn’s disease have a high prevalence of vitamin A deficiency. Without enough vitamin A, a person can develop dry eye disease. Dry eye disease is a condition where a person doesn’t have enough tears to moisten the eye, or produces tears that are of poor quality. Dry eye symptoms can include burning, blurred vision, and a feeling that something is in the eye. Drugs are available that increase tears, lubricate the eye, or control inflammation.

The best way to prevent eye complications as a result of Crohn’s disease is to develop a successful treatment plan with your doctor to manage your IBD. See your eye doctor regularly to detect trouble early, as early treatment is the best way to maintain healthy vision.