Sir,

Recovery of a parasite from the anterior chamber of the eye is a rare event despite the fact that some nematode infections such as onchocerciasis and toxocara are common in certain geographical locations around the world.1 We report a case of ocular Angiostrongyliasis in which a live, motile nematode was seen swimming in the anterior chamber, and subsequently successfully removed from the eye.

A 33-year-old white South African man presented with a 2-day history of a painful, red right eye. He had also noticed floaters in the right eye for 5 days. He was in good general health and denied general malaise or headaches.

On ocular examination his visual acuity was 6/9 in the right eye and 6/5 in the left eye. In addition, anterior uveitis with 2+ inflammatory cells together with a live worm (Figure 1) was noted in the right eye. Intraocular pressure in the right eye was elevated at 34 mmHg. The nematode was removed intact using an irrigating/aspirating cannula through a paracentesis. The patient was treated with Gt Pred forte 1% 2 hourly, Gt Chloramphenicol four times a day, and Gt Levobunolol twice daily. The drops were tapered and stopped 4 weeks after surgery as the intraocular pressure and inflammation settled. Posterior segment examination showed white sub-retinal marks in the inferonasal periphery of the right eye but visual acuity was 6/6. There was no associated vitreous activity, and the appearance remained unchanged at the final follow-up (4 months).

Figure 1
figure 1

The worm in the anterior chamber of the right eye.

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The patient was referred to a tropical diseases unit for systemic review, and the nematode was sent to parasitologists for identification. No evidence of systemic parasitic infection was found. The worm was identified as an immature female of Angiostrongylus cantonensis (Figure 2), a round worm measuring 22.0 mm in length and 0.35 mm in diameter.

Figure 2
figure 2

Light micrograph of Angiostrongylus cantonensis following removal from the eye (magnification x25).

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Angiostrongyliasis most commonly occurs in Southeast Asian countries and has been reported from Taiwan, Thailand, Indonesia, Vietnam, Papua New Guinea, Japan, and Sri Lanka. On reviewing the literature, 14 previously reported cases were found.2, 3, 4, 5 Clinical findings included anterior uveitis, episcleritis, raised intraocular pressure, macular oedema, pigment dispersion, and retinal detachment.

Angiostrongylus cantonensis, a lung fluke of rodents, was first described by Chen in 1935 from the bronchial tree of Rattus norvegicus and R.rattus rattus, caught in Canton, China.6 It is a delicate filiform worm, and has a length of 16-25 mm and a maximum diameter of 0.26-0.36 mm; the female of the species is larger. The rodent is the definite host. It is thought that humans are infected by eating inadequately cooked intermediate hosts (slugs, snails, crabs), or vegetables contaminated by larvae. The most likely routes of entry into the orbit are between the optic nerve and sheath, through the cribriform plate, and into the anterior chamber through the limbus.

It is difficult to know where our patient came into contact with the infected intermediate molluscum host. Although he is resident in the United Kingdom, he had recently visited South Africa. Medline search, however, revealed no previous reports of ocular Angiostrongyliasis from United Kingdom or South Africa.