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Sympathetic ophthalmia (SO), also called spared eye injury, is a diffuse
granuloma A granuloma is an aggregation of macrophages (along with other cells) that forms in response to chronic inflammation. This occurs when the immune system attempts to isolate foreign substances that it is otherwise unable to eliminate. Such sub ...
tous inflammation of the uveal layer of both eyes following trauma to one eye. It can leave the affected person completely blind. Symptoms may develop from days to several years after a penetrating eye injury. It typically results from a delayed hypersensitivity reaction.


Signs and symptoms

Eye floaters and loss of accommodation are among the earliest symptoms. The disease may progress to severe inflammation of the uveal layer of the eye (uveitis) with pain and sensitivity of the eyes to light. The affected eye often remains relatively painless while the inflammatory disease spreads through the uvea, where characteristic focal infiltrates in the choroid named Dalén–Fuchs nodules can be seen. The retina, however, usually remains uninvolved, although perivascular cuffing of the retinal vessels with inflammatory cells may occur. Swelling of the optic disc (papilledema), secondary glaucoma,
vitiligo Vitiligo (, ) is a chronic autoimmune disorder that causes patches of skin to lose pigment or color. The cause of vitiligo is unknown, but it may be related to immune system changes, genetic factors, stress, or sun exposure, and susceptibili ...
, and poliosis of the eyelashes may accompany SO.


Pathophysiology

Sympathetic ophthalmia is currently thought to be an autoimmune inflammatory response toward ocular
antigens In immunology, an antigen (Ag) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. An ...
, specifically a delayed
hypersensitivity Hypersensitivity (also called hypersensitivity reaction or intolerance) is an abnormal physiological condition in which there is an undesirable and adverse immune response to an antigen. It is an abnormality in the immune system that causes Imm ...
to
melanin Melanin (; ) is a family of biomolecules organized as oligomers or polymers, which among other functions provide the pigments of many organisms. Melanin pigments are produced in a specialized group of cells known as melanocytes. There are ...
-containing structures from the outer segments of the photoreceptor layer of the
retina The retina (; or retinas) is the innermost, photosensitivity, light-sensitive layer of tissue (biology), tissue of the eye of most vertebrates and some Mollusca, molluscs. The optics of the eye create a focus (optics), focused two-dimensional ...
. The immune system, which normally is not exposed to ocular proteins, is introduced to the contents of the eye following traumatic injury.A cautionary tale from the past
by K. Barry Sharpless, in MIT Tech Talk; published March 19, 1992; retrieved May 10, 2016
Once exposed, it senses these antigens as foreign, and begins attacking them. The onset of this process can be from days to years after the inciting traumatic event.


Diagnosis

Diagnosis is clinical, seeking a history of eye injury. An important differential diagnosis is Vogt–Koyanagi–Harada syndrome (VKH), which is thought to have the same pathogenesis, without a history of surgery or penetrating eye injury. Still experimental, skin tests with soluble extracts of human or bovine uveal tissue are said to elicit delayed hypersensitivity responses in these patients. Additionally, circulating antibodies to uveal antigens have been found in patients with SO and VKH, as well as those with long-standing uveitis, making this a less than specific assay for SO and VKH.


Treatment

Because SO is so rarely encountered following eye injury, even when the injured eye is retained, the first choice of treatment may not be enucleation or evisceration, especially if there is a chance that the injured eye may regain some function. Additionally, with current advanced surgical techniques, many eyes once considered nonviable now have a fair prognosis. However, only if the injured eye has completely lost its vision and has no potential for any visual recovery, prevention of SO is done by enucleation of the injured eye preferably within the first 2 weeks of injury. Evisceration—the removal of the contents of the globe while leaving the sclera and
extraocular muscles The extraocular muscles, or extrinsic ocular muscles, are the seven extrinsic muscles of the eye in human eye, humans and other animals. Six of the extraocular muscles, the four recti muscles, and the superior oblique muscle, superior and inferior ...
intact—is easier to perform, offers long-term orbital stability, and is more aesthetically pleasing, i.e., a greater measure of movement of the prosthesis and thus a more natural appearance. There is concern, however, that evisceration may lead to a higher incidence of SO compared to enucleation. Several retrospective studies involving over 3,000 eviscerations, however, have failed to identify a single case of SO. Once SO is developed, immunosuppressive therapy is the mainstay of treatment. When initiated promptly following injury, it is effective in controlling the inflammation and improving the prognosis. Mild cases may be treated with local application of
corticosteroids Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are invol ...
and pupillary dilators. More severe or progressive cases require high-dose systemic corticosteroids for months to years. Patients who become resistant to corticosteroids or develop side effects of long-term corticosteroid therapy (osteoporosis and pathologic fractures, mental status changes, etc.), may be candidates for therapy with chlorambucil, cyclophosphamide, or
ciclosporin Ciclosporin, also spelled cyclosporine and cyclosporin, is a calcineurin inhibitor, used as an immunosuppressant medication. It is taken Oral administration, orally or intravenously for rheumatoid arthritis, psoriasis, Crohn's disease, nephr ...
.


Epidemiology

Sympathetic ophthalmia is rare, affecting 0.2% to 0.5% of non-surgical eye wounds, and less than 0.01% of surgical penetrating eye wounds. There are no gender or racial differences in incidence of SO.


History

Although descriptions of sympathetic ophthalmia can be found in ancient Greek texts, modern understanding of SO derives from the works of Scotland's William MacKenzie who characterized and named the disease sympathetic ophthalmitis. At MacKenzie's time, oral mercury and leeches applied to the
conjunctiva In the anatomy of the eye, the conjunctiva (: conjunctivae) is a thin mucous membrane that lines the inside of the eyelids and covers the sclera (the white of the eye). It is composed of non-keratinized, stratified squamous epithelium with gobl ...
were the treatments of choice for SO. It is thought that Louis Braille, who injured one of his eyes as a child, lost vision in his other eye owing to SO. James Thurber's adult blindness was also diagnosed as sympathetic ophthalmia deriving from the loss of an eye when he was six years old.


See also

* Vogt–Koyanagi–Harada disease


References


External links

{{DEFAULTSORT:Sympathetic Ophthalmia Eye diseases Autoimmune diseases