Year : 2004 | Volume
: 52 | Issue : 1 | Page : 57--58
Intravitreal live gnathostoma spinigerum
Samar K Basak, Tushar K Sinha, D Bhattacharya, Tushar K Hazra, S Parikh
Disha Eye Hospitals and Research Centre, Barrackpore, West Bengal, India
Samar K Basak
Disha Eye Hospitals and Research Centre, Barrackpore, West Bengal
Intraocular infestation by live Gnathostoma spinigerum is a rare occurrence in humans. Most of the published reports are from South-East Asia. We report a case of intravitreal gnathostomiasis, where the worm was removed live and intact by pars plana vitrectomy.
|How to cite this article:|
Basak SK, Sinha TK, Bhattacharya D, Hazra TK, Parikh S. Intravitreal live gnathostoma spinigerum.Indian J Ophthalmol 2004;52:57-58
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Basak SK, Sinha TK, Bhattacharya D, Hazra TK, Parikh S. Intravitreal live gnathostoma spinigerum. Indian J Ophthalmol [serial online] 2004 [cited 2013 May 23 ];52:57-58
Available from: http://www.ijo.in/text.asp?2004/52/1/57/14630
Human ocular infestation by live Gnathostoma spinigerum is a rare occurrence and has been reported mostly from South-East Asia. It involves the eyelids, conjunctiva, cornea, anterior chamber, uvea and vitreous cavity. The first case of ocular gnathostomiasis was reported from India in 1945 by Sen et al. A Medline search suggests that among 18 cases of reported intraocular gnathostomiasis so far, intravitreal live parasite was found only in four cases. ,,,Here, we report one case of live intravitreal gnathostomiasis, where the parasite was successfully removed by pars plana vitrectomy. Identification of the worm was confirmed by light microscopy.
A 50-year-old male presented with pain, marked periocular swelling and gross dimness of vision in his right eye for one week. His left eye was normal, with 6/6 vision. The right eye had 3/60 vision. Further ocular examination was not possible because of the severe chemosis and periocular swelling. He was given a course of broad-spectrum antibiotics and oral prednisolone (60 mg/day for 5 days). The inflammation almost subsided with treatment and full ocular examination was then possible. Five days later, examination of the right eye showed visual acuity of 6/9 with normal anterior segment. Indirect ophthalmoscopy revealed a live worm as a motile floater in the anterior vitreous cavity just behind the lens at the 5 o'clock meridian [Figure 1]. The movement of the worm was better seen under the operating microscope in higher magnification. The patient was asked to continue oral corticosteroids for another 15 days in tapering doses.
The peripheral blood smear was essentially normal with no eosinophilia, and no detectable microfilaria. Systemic examination showed no abnormality. No cutaneous lesion was detected. MRI of brain and orbit did not show any evidence of other parasitic infestation.
Pars plana vitrectomy was planned to remove the worm intact and live. During vitrectomy, as soon as the parasite was isolated from surrounding vitreous, it fell to the bottom of the vitreous cavity, over the macula. The worm showed movement even in its new position. Further vitrectomy was then carried out and a posterior vitreous detachment (PVD) was induced. The worm was aspirated gently from the macula with a 20-gauge flute needle and was removed from the eye. The worm, measuring about 3 mm in length and 0.5 mm in diameter was alive and actively motile upon removal from the eye [Figure 2]. On light microscopy, it was identified as a third stage larva of Gnathostoma spinigerum [Figure 3][Figure 4]. After surgery, the patient's condition improved and he regained 6/6 vision in his right eye in two weeks.
Common definitive hosts of Gnathostoma are domestic cats, dogs, and wild animals. Man is an accidental host. Adult worms anchor to the stomach of the definitive hosts and lay eggs. Eggs are liberated in the stools and are hatched in fresh water as first stage larvae. These larvae are ingested by Cyclops, in which second stage larvae develop. Infected Cyclops is ingested by fresh water fish, frogs, snakes, etc., which act as intermediate hosts. Third stage larvae develop within these animals. These infected intermediate hosts may be ingested by other animals, eg, chickens, pigs, or ducks (paratenic hosts), where the third stage larvae can exist without further maturation. Man can be infested by eating the raw or undercooked meat of such intermediate or paratenic hosts. Third stage larvae cannot mature in humans, but they may remain alive up to 10 years. In humans, they may migrate to various organs, including the eye. The mode of entry of Gnathostoma larva into the eye is not clearly known. Fresh chorioretinal haemorrhage close to the optic disc has been observed in a few cases and has been thought to be the mode of entry. Similar retinal haemorrhages were not noticed in the present case.
The most common clinical presentation in ocular gnathostomiasis described earlier was anterior uveitis, though Sen et al also have described lid oedema, conjunctival chemosis and orbital cellulitis. The patient discussed here was unique in the sense that he initially presented with severe chemosis and periocular swelling, which resolved with systemic corticosteroids.
Once the parasite is identified in the vitreous cavity, it should be removed immediately, intact and live, as it is capable of migrating to various part of the eye and could cause structural damage and severe intraocular reaction. In this situation, pars plana vitrectomy is indicated. The parasite can be gently sucked into a 20 gauge flute needle and removed intact. It is not unusual for the parasite to be cut into parts during removal. A severed parasite may cause serious intraocular inflammation.,
This rare case illustrates that intraocular Gnathostoma spinigerum can cause periocular inflammation and the patient may present with severe chemosis and periocular swelling. An initial course of systemic corticosteroids is essential to reduce inflammation. Removal of the intact parasite can ensure restoration of vision.
Prof. Dilip Bera, Head of the Department, Helminthiology, School of Tropical Medicine, Kolkata, West Bengal, India helped in identification of the parasite
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