Causes of Uveitis
Uveitis is caused by a wide range of infectious and non-infectious conditions, with systemic inflammatory disorders being the most common etiology in developed countries.
Infectious Causes
- Viral infections: Herpes simplex virus (HSV), varicella-zoster virus (VZV), cytomegalovirus, and Epstein-Barr virus can all cause immunologically mediated corneal infiltrates that may resemble bacterial, fungal, or Acanthamoeba keratitis and lead to uveitis 1
- Bacterial infections: Tuberculosis, syphilis, Lyme disease, and Whipple's disease can cause uveitis, sometimes with concomitant joint inflammation 2
- Fungal infections: Candida species, particularly Candida albicans, can cause endogenous endophthalmitis through hematogenous spread during candidemia 3
- Parasitic infections: Toxoplasmosis is one of the most frequent specific causes of uveitis in children 1 and remains an important cause in adults 4
Non-Infectious/Autoimmune Causes
- Spondyloarthritis: The leading cause of uveitis in western countries, typically presenting as acute, unilateral anterior uveitis 2
- HLA-B27-associated conditions: Including ankylosing spondylitis, psoriatic arthritis, and inflammatory bowel disease 1
- Juvenile idiopathic arthritis: A significant cause of uveitis in children requiring prompt diagnosis and treatment 1
- Inflammatory bowel disease: Posterior uveitis occurs in less than 1% of patients but can be sight-threatening if left untreated 5
- Psoriasis: Associated with increased risk of uveitis, especially in patients with psoriatic arthritis 1
- Sarcoidosis: An underestimated cause of uveitis, occurring in approximately 15% of cases, with a predilection for middle-aged women 2
Specific Syndromes
- Vogt-Koyanagi-Harada disease: Characterized by bilateral, diffuse choroiditis with serous retinal detachments, typically affecting young adults and associated with neurologic, auditory, and integumentary manifestations 5
- White dot syndromes: A group of inflammatory disorders characterized by multiple white-yellow lesions at the level of the retinal pigment epithelium, choroid, or both 5
Risk Factors
- Immunosuppression: A significant risk factor for infectious causes of uveitis, particularly Candida endophthalmitis 3
- Prolonged hospitalization and indwelling catheters: Risk factors for candidemia leading to endophthalmitis 3
- Genetic factors: HLA-B27 is strongly associated with certain types of uveitis 6
- Environmental factors: Air pollution has been linked to increased incidence of uveitis 6
Idiopathic Uveitis
- In the US and Europe, 27% to 51% of uveitis cases are idiopathic, with no identifiable cause despite thorough evaluation 6
Clinical Implications
- Untreated uveitis may lead to serious complications including cataracts, glaucoma, macular edema, retinal detachment, optic nerve damage, and vision loss 6
- Early identification and appropriate treatment are essential to prevent permanent vision loss 5
- All patients with candidemia should have a dilated retinal examination within the first week of therapy to rule out endophthalmitis 3
- Screening for latent or active infections, particularly tuberculosis, is essential before starting systemic immunomodulatory therapy 5
Understanding the diverse causes of uveitis is crucial for appropriate management and prevention of vision-threatening complications.