Sympathetic Ophthalmia - A Rare but Devastating Inflammatory Disorder

Introduction

Sympathetic ophthalmia is a rare diffuse granulomatous intraocular inflammation affecting both eyes, occurring within days or months following a corrective surgery or trauma to just one of the eyes. The eye that faces surgery or trauma is the exciting eye, and the fellow eye that develops unreasonable inflammation is the sympathetic eye. The sympathetic eye shows signs of granulomatous inflammation without any underlying cause. Untreated, it can cause bilateral blindness. Louis Braille, the inventor of the greatest gift for blinds (braille script), has been hypothesized to have been disabled by this condition. His left eye was injured by a knife wound at the age of 3, which led to complete vision loss by age 5.

Who Is Susceptible to Sympathetic Ophthalmia?

Medical literature trials carry a history of sympathetic ophthalmia, so it is difficult to know the real number of cases throughout history. Additionally, the record-keeping has been suboptimal since the diagnosis is primarily through clinical observations and no laboratory history.

According to estimates, the incidence of sympathetic ophthalmia stands at 0.01 % following pars plana vitrectomy, 0.06 % after penetrating ocular traumas, and about 0.01 % after ophthalmic surgeries. The condition accounted for 0.3 % of uveitis cases and an annual incidence of a minimum of 0.03 per 100,000 population, translating into three cases per 10 million individuals. The condition shows no racial or age predilection. However, males with ocular trauma have reported more incidents than females. Sympathetic ophthalmia occurs more frequently after non-surgical traumas. It has been observed that people who are reporting sympathetic ophthalmia express HLA DR4 antigen (human leukocyte antigen DR4), which might indicate a genetic predisposition.

What Leads to Sympathetic Ophthalmia?

Prior trauma or a history of ocular surgery have been surveyed to have been causative of sympathetic ophthalmia. Usually, inflammation develops within five to 66 days of injury. Vitrectomy and cyclo-destructive procedures have been considered high risk for sympathetic ophthalmia.

T-cells are regarded as the primary mediator of inflammation which invades the uveal tract. CD4+ helper T-cells primarily ride the initial wave of infiltrative cells, and CD8+ cytotoxic T-cells surf the later waves. Studies have shown proliferative T-cell responses to uveal monocytes in patients. The inflammation is typically granulomatous, and the choroid is diffusely thickened by lymphocytes, epithelioid cell nests, and multinucleated giant cells; the latter two are usually pigmented.

The condition is differentiated from Voyt-Koyanagi-Harada syndrome by the absence of choriocapillaris and retinal involvement. Dalen-Fuchs nodules (pigmented epithelioid cells in the retina and choroid) are commonly seen. The iris appears thickened by nodular infiltration when viewed anteriorly. The classical signs of the condition are accompanied by conjunctival injection and a granulomatous anterior chamber reaction with mutton-fat-keratic-precipitates (inflammatory cells that coalesce and yellows) on corneal epithelium, whereas the inflammation can be very mild in the anterior chamber. Intraocular pressure may be elevated due to blockage of the trabecular meshwork by inflammatory cells that results secondary to ciliary body closure.

What Are the Clinical Features of Sympathetic Ophthalmia?

The signs and symptoms of sympathetic ophthalmia can develop anywhere between five days to several years.

The clinical features are:

• Eye floaters.

• Loss of accommodation.

• Bilateral uveitis (inflammation of the uveal layer of the eye).

• Pain.

• Light sensitivity (photophobia).

• Swelling of the optic disc (papilledema).

• Secondary glaucoma.

• Vitiligo.

• Poliosis of eyelashes (loss of pigmentation).

• Blurry vision.

• Epiphora (excessive tear formation).

• Vitritis (cellular infiltration of the vitreous body).

• Retinal vasculitis (sight-threatening inflammatory eye condition).

• Choroiditis (inflammation of the choroid and the retina).

• Papillitis (inflammation and deterioration of the optic disk).

• Retinal detachment.

• Optic nerve swelling.

How to Diagnose Sympathetic Ophthalmia?

Sympathetic ophthalmia is diagnosed primarily via detailed clinical history and examination. There are no diagnostic laboratory investigations. Fluorescein angiography and indocyanine green video-angiography are the two adjunct tools used to determine the extent and severity of the inflammation.

In acute stages, multiple leakage sites are detected at the retina pigment epithelium that also persists into the later stages. A gradual accumulation of Dalen–Fuchs nodules shows up as focal hyperfluorescence due to the simultaneous dye stack. Even the optic nerve head gets stained in the late stages, which is diagnostic of nerve head swelling.

Time-domain optical coherence tomography shows retinal disorganization, thinning retinal pigment epithelium, and choriocapillaris disintegration. B-scan ultrasonography shows marked choroid thickening and retinal detachment.

How to Treat Sympathetic Ophthalmia?

The primary treatment protocol for sympathetic ophthalmia includes corticosteroids which need to be started soon after diagnosis, keeping in mind the contraindicative factors. In acute stages, intravenous Methylprednisolone pulse therapy has been proven to reduce posterior segment alterations rapidly. Immunomodulators like Cyclosporine and Azathioprine are also prescribed. Sympathetic ophthalmia is one of the few conditions where immunosuppressive therapy is indicated soon after diagnosis.

Surgical options may also be considered when the injured eye has completely lost all scope of any vision recovery. To prevent sympathetic ophthalmia, enucleation of the injured eye may be performed, preferably within a fortnight of injury. Evisceration (globe content removal leaving the sclera and intraocular muscles intact) is an easier procedure and provides the additional benefit of greater stability and aesthetics, albeit with prosthetics.

The patients require close monitoring and may require hospitalization in case of inefficient in-house therapeutic care. The patients must visit the specialist for regular small-interval follow-ups unless the doctor decides to space out the visits.

What Is the Prognosis of Sympathetic Ophthalmia?

Sympathetic ophthalmia is a serious condition with a high potential disability. More than half of the diagnosed patients get 20/40 or worse vision grades, and close to 35 % of patients go completely blind. Pertaining to the recent advancements in ophthalmology, it is possible to stabilize and enhance the ocular outcome even in the exciting eye. A better prognosis can be expected only when the diagnosis is made at earlier stages, and aggressive treatment modalities are adopted.

What Is the Differential Diagnosis of Sympathetic Ophthalmia?

• Vogt-Koyanagi-Harada syndrome.

• Sarcoidosis.

• Posterior syphilis.

• Tuberculosis.

What Are the Complications of Sympathetic Ophthalmia?

• Retinal detachment.

• Permanent blindness.

Conclusion

Sympathetic ophthalmia is a rare inflammatory condition with a very peculiar progression, as even the unaffected eye can undergo complete blindness. The condition can be considered a delayed hypersensitive reaction. With prompt and aggressive treatment modes, the patient can regain some amount of vision. In case an ocular recovery is out of range, it is advisable to proceed with the scalpel and get the exciting eye removed to keep the other eye damage-free. With the advancement of three-dimensional scanning and printing, highly accurate prosthetics are available for patients.