Infection of the human eye by Toxocara larvae is known to occur. It is not known whether ocular toxocariasis represents a late or early stage in this infection. This study was done to determine the interval between infection and larval invasion of the eye. Mice were given a single dose of Toxocara canis eggs (120 to 200 per gram of body weight), and necropsy was done on the animals at various intervals after infection; their eyes were removed and examined microscopically. Larvae were recorded as early as day 3. After the 1st week of infection, the number of worms in the eyes tended to level off during the next 4 months. Onset of hemorrhage (anterior chamber) coincided with onset of eye invasion; hemorrhage was noted during the 1st month of infection. The areas anterior and posterior to the lens were infected at the same time, although the posterior portion harbored more larvae.
Present address: Department of Dermatology, Baylor College of Medicine, Houston, Texas 77000.