An ophthalmologist recently removed a 9.5-cm-long filarial worm from the eye of a 52-year-old man.
Jayan Thomas, who has been specialising in eye care for 30 years in Kannur, said he never confronted such a roundworm in the eye in his long practice.
Histopathologists who examined the worm confirmed that it was a dirofilaria or a dog heartworm transmitted by mosquitoes from a dog or a cat. Although dirofilarial infections in human beings are not very rare, the worm reaching the eye or ophthalmic dirofilariasis is uncommon, according to the Indian Journal of Ophthalmology.
“I was surprised to find the worm coiled up and moving under the conjunctiva when I examined the patient’s eye under a slit lamp. The man who reached me in the morning with a swollen red eye had begun to experience the pain from the previous night when the worm presumably entered his eye by piercing the blood vessel of the eye,” said Dr. Thomas.
By secreting some toxins, the worm had caused a haemorrhage of the conjunctiva. Dr. Thomas soon paralysed the worm and took it out through a surgical procedure. “My worry was that the worm should not escape from the eye back into the body. If it could come into the eye, it can go back as well,” he said.
He said people were largely unaware of the transmission of dog heartworms into human bodies. Dog heartworms or dirofilarial parasites are usually found in the heart and lungs of dogs, cats, and foxes. They reach human bodies through mosquitoes such as Culex and Aedes. According to the Indian Journal of Ophthalmology, man is a dead-end host for this filarial parasite.
Dr. Thomas said the dirofilarial worm usually would go and lie under the skin or reach the lungs in human bodies. “But reaching the eye is uncommon. I have heard about such cases, but could never see one before. And, I think the 9.5-cm-long worm could be the biggest removed from an eye in Kerala,” he said.
But Dr. Thomas’ claim could not be corroborated. “What I want to tell the people is that they should be careful about mosquitoes. They can spread a lot of diseases,” he said.
He suggested periodic deworming with medicines like diethylcarbamazine as a precaution against such parasites. “Those deworming tablets can kill the worms in the body. They are quite effective,” he said.
