Ocular Larva Migrans (OLM) is a parasitic infection of the eye caused by the migration of larval stages of certain animal parasites. The most common causative agents are Toxocara species, particularly Toxocara canis and Toxocara cati, which are roundworms commonly found in the intestines of dogs and cats, respectively. These parasites shed their eggs in the feces of infected animals, contaminating soil, sand, and other substrates. Human infection occurs when individuals inadvertently ingest these eggs, either through direct contact with contaminated surfaces or by consuming contaminated food or water.

Once ingested, the eggs hatch into larvae in the intestines and penetrate the intestinal wall, entering the bloodstream and disseminating to various organs, including the eyes. The larvae have a predilection for ocular tissues, where they induce inflammation, tissue damage, and potentially severe ocular complications. While OLM primarily affects the eyes, larval migration can also occur in other organs, leading to a condition known as visceral larva migrans (VLM).

The clinical presentation of OLM can vary depending on the location and extent of larval migration within the eye. Common ocular symptoms may include:

• Blurred vision or vision loss, which may be sudden or progressive, depending on the severity of ocular involvement.
• Floaters or spots in the field of vision, indicative of retinal inflammation or detachment caused by larval migration.
• Redness, irritation, or pain in the affected eye, often accompanied by photophobia (sensitivity to light) and excessive tearing.
• Inflammation of the anterior and/or posterior segments of the eye, including the conjunctiva, iris, ciliary body, retina, and optic nerve.

Diagnosing OLM requires a comprehensive evaluation by an ophthalmologist and may involve several diagnostic modalities:

• Clinical assessment: The ophthalmologist will conduct a thorough examination of the eyes, assessing visual acuity, intraocular pressure, pupillary reactions, and ocular motility.
• Ophthalmic imaging: Imaging studies, such as optical coherence tomography (OCT), fundus photography, and fluorescein angiography, may be performed to visualize retinal changes, choroidal inflammation, and larval migration within the eye.
• Serological testing: Blood tests, including enzyme-linked immunosorbent assay (ELISA) or Western blot, may be conducted to detect specific antibodies against parasitic antigens, providing supportive evidence for the diagnosis of OLM.
• Conjunctival biopsy: In some cases, a biopsy of conjunctival tissue may be performed to identify larval fragments or inflammatory changes consistent with OLM.

The management of OLM aims to eradicate the parasitic infection, alleviate symptoms, and prevent further ocular damage. Treatment modalities may include:

• Anthelmintic medications: Oral anthelmintic drugs, such as albendazole or mebendazole, are commonly prescribed to kill parasitic larvae and inhibit their migration within the eye. These medications are typically administered for several weeks to ensure complete eradication of the parasites.
• Corticosteroid therapy: Topical or systemic corticosteroids may be prescribed to reduce ocular inflammation, minimize tissue damage, and alleviate symptoms such as pain, redness, and photophobia.
• Surgical intervention: In severe cases of OLM associated with significant ocular complications, such as retinal detachment or intraocular cyst formation, surgical procedures may be necessary to remove larval cysts, repair retinal tears, or restore ocular anatomy and function.

Preventing OLM involves minimizing exposure to contaminated environments and adopting appropriate hygiene practices:

• Avoiding contact with soil, sand, or other substrates potentially contaminated with animal feces, especially in areas where dogs and cats are present.
• Practicing thorough hand hygiene, particularly after handling pets or engaging in outdoor activities, to minimize the risk of ingesting parasitic eggs.
• Educating individuals, especially children, about the dangers of geophagia (ingestion of soil) and the importance of proper sanitation and hygiene practices.
• Regular deworming of pets and proper disposal of animal feces to reduce environmental contamination and prevent the spread of parasitic infections to humans.

It is essential to seek prompt medical attention if you experience any of the following signs or symptoms suggestive of Ocular Larva Migrans:

• Sudden or progressive vision changes, such as blurred vision, vision loss, or the appearance of floaters.
• Redness, irritation, or pain in the eyes, especially if accompanied by sensitivity to light or excessive tearing.
• History of exposure to potentially contaminated environments or animals, such as playing in soil or contact with pets.
• Any other concerning ocular symptoms that warrant evaluation by an eye care professional.

Ocular Larva Migrans is a rare but potentially sight-threatening parasitic infection that necessitates prompt diagnosis and appropriate treatment. By understanding its causes, symptoms, diagnosis, treatment options, prevention strategies, and when to seek medical attention, individuals can take proactive steps to safeguard ocular health and well-being. Early detection, coupled with preventive measures and timely medical intervention, is paramount in mitigating the risk of vision loss associated with Ocular Larva Migrans. Maintaining awareness and seeking appropriate medical care when needed are crucial elements in the comprehensive management of this ocular condition.

World Eye Care Foundation’s eyecare.live brings you the latest information from various industry sources and experts in eye health and vision care. Please consult with your eye care provider for more general information and specific eye conditions. We do not provide any medical advice, suggestions or recommendations in any health conditions.