Published: 18 Jun 2025

ICD9: 360.11      ICD10: H44.139      ICD11: 9A96

Sympathetic uveitis (SU) is a rare but severe form of bilateral (affecting both eyes) granulomatous uveitis that typically occurs after penetrating injury or surgery to one eye (the exciting eye).
The other eye, which was initially healthy, becomes inflamed (the sympathizing eye).

Here's a breakdown of what's important to know about sympathetic uveitis:

Key Features:

Triggering Event: A penetrating injury (e.g., trauma, surgery) to one eye is the trigger. The risk is higher with injuries involving the ciliary body.
Bilateral Inflammation: The hallmark is inflammation in both eyes, even though only one was initially damaged.
Granulomatous Uveitis: The inflammation is a specific type called granulomatous, meaning it involves collections of immune cells called granulomas.
Delayed Onset: It usually develops weeks to months (typically 2 weeks to several months, but can be years) after the initial injury/surgery. In extremely rare cases, it can occur after just days.
Autoimmune Reaction: SU is believed to be an autoimmune reaction where the body's immune system attacks proteins within the eye that were previously "hidden" from the immune system (antigens that were not previously exposed to immune cells). The injury releases these proteins, and the immune system mistakenly identifies them as foreign invaders.
Sight-Threatening: If left untreated, SU can cause severe vision loss, including blindness, in both eyes.

Symptoms:

Symptoms can vary, but often include:

In the Injured (Exciting) Eye:
Pain
Redness
Blurred vision (may be worse than initially expected after the injury)
Sensitivity to light (photophobia)
Floaters

In the Uninjured (Sympathizing) Eye:
Gradual onset of blurred vision
Pain
Redness
Sensitivity to light (photophobia)
Floaters

Diagnosis:

Diagnosis is based on:

History: A history of penetrating eye injury or surgery in one eye followed by inflammation in the other eye is crucial.
Clinical Examination:
Slit-lamp examination to visualize the inflammation within the eye (cells and protein in the anterior chamber, inflammation of the iris, etc.).
Fundus examination to assess the retina and choroid for signs of inflammation (e.g., Dalen-Fuchs nodules, which are characteristic but not always present).
Imaging Studies:
Fluorescein angiography: To assess blood vessel leakage in the retina and choroid.
Optical coherence tomography (OCT): To evaluate retinal thickness and identify any fluid accumulation.
Ultrasound: To examine the posterior segment of the eye, especially if the view is obscured by inflammation.

Treatment:

The goal of treatment is to suppress the immune system and reduce inflammation. The mainstays of treatment are:

Corticosteroids: High-dose systemic corticosteroids (e.g., prednisone) are the first-line treatment.
Immunosuppressants: Corticosteroid-sparing immunosuppressants (e.g., cyclosporine, azathioprine, mycophenolate mofetil) are often used to reduce the long-term reliance on steroids and minimize their side effects.
Topical Corticosteroids: Eye drops may be used to treat inflammation in the front of the eye.
Cycloplegics: Eye drops to dilate the pupil and relieve pain.
Enucleation: In some cases, if the injured eye has little or no visual potential and is causing severe inflammation, enucleation (removal of the eye) of the injured eye may be considered *early* (within 1-2 weeks of injury). This is a controversial topic and the decision must be made carefully, weighing the risks and benefits. Enucleation is *not* beneficial once sympathetic uveitis has developed in the sympathizing eye.

Prognosis:

The prognosis for sympathetic uveitis depends on several factors, including:

Severity of inflammation: More severe inflammation is associated with a worse prognosis.
Promptness of treatment: Early and aggressive treatment is crucial to preserving vision.
Response to treatment: Some patients respond well to treatment, while others may have chronic or relapsing inflammation.
Presence of complications: Complications such as glaucoma or cataract can worsen the prognosis.

With early diagnosis and aggressive treatment, many patients with sympathetic uveitis can maintain good vision in at least one eye. However, the condition can be difficult to manage and may require long-term immunosuppression.

In summary, Sympathetic Uveitis is a rare, severe, bilateral autoimmune inflammatory condition that occurs after penetrating injury or surgery to one eye. It requires prompt diagnosis and aggressive treatment to prevent vision loss in both eyes.

Disclaimer: This information is for general knowledge purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.