Ocular larva migrans (OLM), also known as ocular toxocariasis, is the ocular form of the larva migrans syndrome that occurs when ''

Toxocara canis ''Toxocara canis'' (also known as dog roundworm) is a worldwide-distributed helminth parasite of dogs and other canids. The name is derived from the Greek word "," meaning bow or quiver, and the Latin word "caro," meaning flesh.Bassert , J., & T ...

'' (dog roundworm) larvae invade the eye. They may be associated with

visceral larva migrans Visceral larva migrans (VLM) is a condition in humans caused by the migratory larvae of certain nematodes, humans being a dead-end host, and was first reported in 1952. Nematodes causing such zoonotic infections are ''Baylisascaris procyonis'', '' ...

. Unilateral visual disturbances,

strabismus Strabismus is a vision disorder in which the eyes do not properly align with each other when looking at an object. The eye that is focused on an object can alternate. The condition may be present occasionally or constantly. If present during a ...

, and eye pain are the most common presenting symptoms.

Diagnosis

The disease presents with an eosinophilic granulomatous mass, most commonly in the posterior pole of the retina. The granulomatous mass develops around the entrapped larva, in an attempt to contain the spread of the larva. ELISA testing of intraocular fluids has been demonstrated to be of great value in diagnosing ocular toxocariasis.

Differential diagnosis

The retinal lesion can mimic

retinoblastoma Retinoblastoma (Rb) is a rare form of cancer that rapidly develops from the immature cells of a retina, the light-detecting tissue of the eye. It is the most common primary malignant intraocular cancer in children, and it is almost exclusively fo ...

in appearance, and mistaken diagnosis of the latter condition can lead to unnecessary ''enucleation''.

Complications

The eye involvement can cause the following inflammatory disorders: *

endophthalmitis Endophthalmitis is inflammation of the interior cavity of the eye, usually caused by infection. It is a possible complication of all intraocular surgeries, particularly cataract surgery, and can result in loss of vision or loss of the eye itself ...

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 ...

chorioretinitis Chorioretinitis is an inflammation of the choroid (thin pigmented vascular coat of the eye) and retina of the eye. It is a form of posterior uveitis. If only the choroid is inflamed, not the retina, the condition is termed choroiditis. The ophthalm ...

Epidemiology

In contrast to visceral larva migrans, ocular toxocariasis usually develops in older children or young adults with no history of pica. These patients seldom have eosinophilia or visceral manifestations.

References

External links

Eye diseases Tropical diseases {{eye-stub