Sympathetic ophthalmia: inflammation in both eyes after one-eye injury

Sympathetic ophthalmia is a form of uveitis, which means inflammation of the middle layer of the eye, that affects both eyes after only one has been injured or operated on. Patient.info describes it as an inflammatory condition affecting both eyes that occurs after a penetrating injury, accidental or surgical, to one of the eyes. The EyeWiki resource of the American Academy of Ophthalmology describes it as a rare, bilateral, granulomatous uveitis caused by exposure of previously hidden eye proteins from trauma or surgery, followed by an autoimmune response to that tissue.

The injured or operated eye is called the exciting eye and the other eye the sympathising eye. Patient.info says the condition is thought possibly to be an autoimmune reaction to the exposed tissue proteins within the damaged eye. In other words, the immune system, which normally never sees these proteins, treats them as foreign and then attacks the same tissue in the healthy eye.

The condition is uncommon. Patient.info cites a figure of about 3 out of every 10,000,000 cases of penetrating injury in one source and an incidence of 0.19 percent after traumatic eye injury in another. It says repeated trauma gives the greatest risk, and that patients who have had vitreoretinal surgery and cyclodestructive procedures are also prone, although less likely, with an incidence after vitreoretinal surgery of around 0.038 percent.

Timing varies a great deal. Patient.info says about two-thirds of cases occur within a fortnight of the injury and 90 percent within the first year, with a documented range of 5 days to 66 years. EyeWiki says the interval is variable and that most cases occur within the first several years, and that vitrectomy and cyclodestructive procedures have been associated with potentially higher rates. Because of the long potential delay, anyone who has had a significant eye injury or operation should know the symptoms for years afterwards.

Patient.info lists deteriorating vision in both eyes, painful red eyes and photophobia (sensitivity to light), in someone with a history of penetrating eye trauma or surgery. EyeWiki describes non-specific symptoms of ocular inflammation, including blurred or decreased vision, pain, photophobia and redness, with reduced near vision typically an early symptom, and an onset that may be gradual or sudden. A history of past injury or surgery, even in the remote past, is central to the diagnosis.

The NHS advises an urgent GP appointment or NHS 111 for eye pain, sensitivity to light, changes in vision such as flashing or blurring, or very red eyes, and says to go to A&E or call 999 if you cannot see. It also advises that a red eye with any change to your sight, pain on looking at light or a severe headache needs immediate attention. If you have had an eye injury or eye surgery, tell the clinician about it straight away, as it changes how these symptoms are interpreted.

• New blurred vision, floaters or reduced near focus in either eye after a past eye injury or operation.

• A painful, red eye or sensitivity to light in the uninjured eye.

• Any sudden loss of vision, which needs A&E or 999.

Diagnosis is clinical and made by an ophthalmologist, usually in a specialist eye unit. Patient.info says any inflammation of an uninvolved eye following trauma to the fellow eye is suspect, and describes the findings on examination: diffuse bilateral intraocular inflammation, which appears as red eyes without a slit lamp, and on slit lamp examination clumps of inflammatory cells on the back of the cornea, hazy fluid in the front of the eye, optic disc swelling and patches of inflammation in the choroid.

Other causes of similar inflammation have to be excluded. Patient.info lists Vogt-Koyanagi-Harada syndrome, sarcoidosis, tuberculosis, syphilis and a lens-related inflammation, and says blood tests and a chest X-ray may be done to rule these out. Imaging such as B-scan ultrasound, fluorescein angiography and optical coherence tomography can help confirm the diagnosis and monitor response. EyeWiki adds that infectious causes must be ruled out before treatment begins because of the risk of worsening an underlying infection.

Patient.info says sympathetic ophthalmia is managed aggressively with steroids, with or without immunosuppressive agents, and that cycloplegic drops may help symptoms. It notes one study in which a steroid implant provided inflammatory control and reduced dependence on systemic immunosuppression. Treatment is directed by an ophthalmologist.

Removal of the previously injured eye may need to be considered if that eye is blind anyway, as this may improve the condition, according to Patient.info. EyeWiki says there is no known benefit to removing the exciting eye once the condition has started, and that the exciting eye may have useful vision after therapy. Decisions about the injured eye are therefore individual and made with the surgeon.

Prevention is the reason that serious eye injuries are repaired promptly. Patient.info lists prompt and meticulous repair of open globe injuries, removal of an injured eye when repair is impossible, and prompt control of inflammation as the key preventive measures.

Patient.info says the prognosis is poor without rapid intervention, but that with aggressive treatment approximately 70 percent of patients improve in visual acuity in the sympathising eye, of which 58.2 percent achieve 20/40 or better. It lists complications including new blood vessels on the iris, which can lead to secondary glaucoma, cataract and retinal detachment, and says very rarely the uveitis follows a mild, self-limiting course.

Long-term follow-up is needed because inflammation can recur. Many people also need support to deal with the combined effects of an eye injury and a new threat to the other eye; your ophthalmology team can signpost sight-loss support services.

Eye injuries are managed in NHS eye casualty and emergency departments, and uveitis is treated in hospital eye services, often with long-term follow-up. Private ophthalmology is available in the UK, but because this is rare and needs specialist uveitis care, referral to an ophthalmologist with that experience is important in either setting. There is no routine NHS patient leaflet for this rare condition that was found while preparing this page, so the main sources are clinician-facing.