Fuchs heterochromic iridocyclitis (FHI) is a chronic unilateral

uveitis Uveitis () is inflammation of the uvea, the pigmented layer of the eye between the inner retina and the outer fibrous layer composed of the sclera and cornea. The uvea consists of the middle layer of pigmented vascular structures of the eye and in ...

appearing with the triad of

heterochromia Heterochromia is a variation in coloration. The term is most often used to describe color differences of the iris, but can also be applied to color variation of hair or skin. Heterochromia is determined by the production, delivery, and concent ...

, predisposition to cataract and

glaucoma Glaucoma is a group of eye diseases that result in damage to the optic nerve (or retina) and cause vision loss. The most common type is open-angle (wide angle, chronic simple) glaucoma, in which the drainage angle for aqueous humor, fluid withi ...

, and keratitic precipitates on the posterior corneal surface. Patients are often asymptomatic and the disease is often discovered through investigation of the cause of the heterochromia or cataract. Neovascularisation (growth of new abnormal vessels) is possible and any eye surgery, such as cataract surgery, can cause bleeding from the fragile vessels in the atrophic iris causing accumulation of blood in the anterior chamber of the eye, also known as hyphema.

Presentation

This condition is usually unilateral, and its symptoms vary from none to mild blurring and discomfort. Signs include diffuse iris atrophy and small white keratic precipitates (deposits on the inner surface of the cornea), cells presenting in the anterior chamber as well as the anterior vitreous.

Glaucoma Glaucoma is a group of eye diseases that result in damage to the optic nerve (or retina) and cause vision loss. The most common type is open-angle (wide angle, chronic simple) glaucoma, in which the drainage angle for aqueous humor, fluid withi ...

and cataract occur frequently.

Complications

* Cataract * Decreased

visual acuity Visual acuity (VA) commonly refers to the clarity of vision, but technically rates an examinee's ability to recognize small details with precision. Visual acuity is dependent on optical and neural factors, i.e. (1) the sharpness of the retinal ...

(vision loss) * Iris atrophy

Causes

According to recent research, not a single theory is able to explain the cause fully. However current plausible theories include infection with '' Toxoplasma gondii'',

Herpes simplex virus Herpes simplex virus 1 and 2 (HSV-1 and HSV-2), also known by their taxonomical names '' Human alphaherpesvirus 1'' and ''Human alphaherpesvirus 2'', are two members of the human ''Herpesviridae'' family, a set of viruses that produce viral in ...

Rubella Rubella, also known as German measles or three-day measles, is an infection caused by the rubella virus. This disease is often mild, with half of people not realizing that they are infected. A rash may start around two weeks after exposure and ...

, neurogenic causes, and autoimmune pathology.

Diagnosis

Diagnosis is made by an

ophthalmologist Ophthalmology ( ) is a surgical subspecialty within medicine that deals with the diagnosis and treatment of eye disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a med ...

optometrist Optometry is a specialized health care profession that involves examining the eyes and related structures for defects or abnormalities. Optometrists are health care professionals who typically provide comprehensive primary eye care. In the Un ...

based on the clinical presentation. One indication can be the

Amsler sign Amsler sign also known as Amsler–Verrey sign is the name of the diagnostic finding seen in people with Fuchs heterochromic iridocyclitis (FHI). It is described as presence of blood (hyphema) in the aspirated aqueous fluid, in paracentesis of the ...

, which is the presence of blood (hyphema) in the aspirated vitreous fluid, in paracentesis of the anterior chamber. This is caused due to iris atrophy usually seen in FHI and exposure of the fragile iris vasculature to the vitreous fluid. The sudden change of pressure in the anterior chamber upon suction induced by the paracentesis, or during cataract surgery, causes bursting of the fragile superficial iris capillaries resulting in micro-bleeding. This is one clinical diagnostic sign of FHI slit-lamp examination shows stringy keratic precipitates

Treatment

Patients usually do not require treatment due to the benign nature of the disease. In case a cataract develops, patients generally do well with cataract surgery.

History

First described using available patient presentations observed, by an Austrian

, Ernst Fuchs in 1906.

Sources

External links

{{Medicine Eye diseases