Fundoscopy Should Be Performed in Patients with Suspected Crohn's Disease Who Develop Blurring of Vision
Patients with suspected Crohn's disease who develop blurring of vision should undergo prompt fundoscopic examination to rule out ocular manifestations of inflammatory bowel disease, particularly uveitis, which can lead to permanent vision loss if left untreated. 1, 2
Ocular Manifestations in Crohn's Disease
Ocular manifestations occur in 4-12% of patients with inflammatory bowel disease (IBD) 3. These manifestations include:
- Anterior uveitis (most common ocular manifestation - 29.3% of cases) 4
- Episcleritis
- Scleritis
- Dry eye syndrome
- Cataracts
Risk Factors for Ocular Involvement
Patients at higher risk for ocular manifestations include:
- Younger patients (mean age 34.5 years vs. 42 years in those without ocular manifestations) 4
- Colonic disease location (52% vs. 7.4%) 4
- Active disease (60% vs. 7.4%) 4
- Presence of other extraintestinal manifestations (48% vs. 3.7%) 4
- First year of disease 4
Diagnostic Approach
Fundoscopic Examination
Fundoscopy is essential in patients with suspected Crohn's disease who develop blurring of vision as it can detect:
- Signs of uveitis (inflammation of the uveal tract)
- Retinal changes
- Optic disc abnormalities
According to the European Crohn's and Colitis Organisation (ECCO) guidelines, patients with ocular manifestations should be referred to an ophthalmologist 1. A complete ophthalmologic evaluation should include:
- Visual acuity testing
- Slit-lamp biomicroscopy
- Fundoscopic examination through dilated pupils
- Intraocular pressure measurement
- Assessment for relative afferent pupil defect
Warning Signs Requiring Urgent Assessment
- Sudden vision loss
- Eye pain
- Photophobia
- Redness
- Floaters
Clinical Significance
Uveitis associated with Crohn's disease is frequently bilateral, insidious in onset, and long-lasting 1. If left untreated, it can lead to serious complications:
- Synechiae (adhesions between the iris and lens)
- Cataracts
- Glaucoma
- Permanent vision loss 2
Early detection through fundoscopy and prompt treatment are crucial to prevent these vision-threatening complications.
Treatment Approach
Treatment depends on the specific ocular manifestation:
- Episcleritis: May not require systemic treatment and usually responds to topical steroids or NSAIDs 1
- Uveitis: Treated with steroids (both topical and systemic routes may be necessary) 1
- Refractory cases: Immunomodulatory therapy including anti-TNF agents may be helpful 1
Case Examples
There are documented cases where ocular manifestations were the presenting symptoms of Crohn's disease. In one case, an adolescent boy presented with sudden onset of visual impairment, which was diagnosed as bilateral anterior uveitis. Further evaluation revealed gastrointestinal symptoms leading to the diagnosis of Crohn's disease 5.
Conclusion
Blurring of vision in patients with suspected Crohn's disease should never be ignored. Fundoscopic examination is a critical component of the evaluation of these patients and should be performed promptly to detect potentially vision-threatening conditions like uveitis. Early diagnosis and treatment can prevent permanent vision loss and improve quality of life.