|Year : 1969 | Volume
| Issue : 3 | Page : 109-113
GN Seal, AK Gupta, MK Das
Department of Ophthalmology, Institute of Post-Graduate Medical Education and Research, Calcutta, India
|Date of Web Publication||10-Jan-2008|
G N Seal
Department of Ophthalmology, Institute of Post-Graduate Medical Education and Research, Calcutta
|How to cite this article:|
Seal G N, Gupta A K, Das M K. Intra-ocular Gnathostomiasis. Indian J Ophthalmol 1969;17:109-13
Ocular infection with Gnathostoma spinigerun is very rare. Sen and Ghose  reported a case of ocular infection in 1945. The patient first presented a picture of orbital inflammation followed by retinal hemorrhages and vitreous opacity. Later on, a severe painful iritis developed with formation of pink nodules on the iris. Subsequently, an immature dead worm of about 4 millimeters long was successfully removed from the anterior chamber. After operation, the inflammation rapidly subsided but optic atrophy resulted and a scar was visible below the macula probably by the wound of entry of the worm from the orbit.
Gnathostoma spinigerum which belongs to super family spiruroidea, was first discovered by Owen in 1836 from the gastric tumour of a tiger. It is commonly found in Thailand, India, Malayan States, China and Japan. The adult parasites are usually found in the alimentary tract of domestic or wild cats and dogs and large carnivoras like tiger. Human beings are not definitive hosts and harbour immature worms (larva). It is not known whether the infection is acquired by animals or man by eating infected fish or by drinking water containing infected cyclops. About 25 cases of proved human infection almost all from Thailand, have been reported. - Sorsby.  In most of these cases, there are development of dermal or Subdermal nodules.
Morphology- Adult parasite is a short nematode, reddish-brown in colour, having a globular cephalic dome separated from the rest of the body by a constriction. The anterior half of the body is provided with fine leaf-like spines while the posterior portion is relatively smooth. The head is globular which carries 4 to 8 transverse rows of hooklets. The mouth is guarded by a pair of fleshy lips. The male is 11 to 25 mm. in length and about 2 mm in breadth; the female is 25 to 54 mm in length. The vulva is situated behind the middle of the body. The eggs are oval, having a mucoid plug at one of their poles. They measure about 70 x 40 microns.
Life cycle - The adult worm lives in the gastric tumour of cats or dogs. The eggs come out with the faces and in a week's time, motile larva, (measuring 265 x 16 microns) hatch out in water. The larva are ingested by cyclops and in two weeks' ingested they develop into second-stage larva. A second intermediate host is required to complete the larval development. The second intermediate host is either a fish or amphibian like frog or snake. A third-stage larva is developed in this host and found encysted in the flesh of this animal. The definitive hosts, i.e. cats or dogs, acquire the infection by eating this infected flesh. The parasite takes about 7 to 8 months to be matured in the stomach.
Pathogenicity - The parasite produces tumours in the stomach and intestine. In man, such pathological lesion cannot be produced as the parasites are unable to grow up to the adult stage. Immature worms with four cephalic rows of hooklets (larva) when ingested by man, may either localise in the visceral organs or may migrate through the subcutaneous tissues causing fugitive swellings. These young worms have been recovered from the skin nodules of various parts of the body. In a similar way, the larva may migrate and reach the orbital tissue and occasionally penetrate the posterior wall of the eyeball to get inside.
The presence of the worm in any part causes an inflammatory reaction with cellular infiltration consisting of eosinophils and plasma cells. With subsequent secondary infection, the inflammatory nodules undergo suppuration leading to abscess formation. The worm, either alive or dead, may be found within the abscess. Inside the eye, the larva may produce chorioretinitis or irridocyclitis when it migrates into the anterior segment of the eyeball.
We are reporting below two cases of ocular Gnathostomiasis where the worm produced exudative irridocyclitis. In both the cases, actively motile larvae successfully removed from the anterior chamber through limbal section.
| Case Report|| |
Durga Ghati, a young Hindu woman aged 32 years was first seen in the Eye Department, Seth Sukhlal Karnani Memorial Hospital, Calcutta, on 22nd December, 1962 with the complaint of sudden attack of pain and redness in her right eye for 7 days. She also had dimness of sight in that eye since then.
General Examination: Patient's general condition was fair and she was afebrile. The condition of her teeth and gum was very bad. There vas no evidence of any skin nodules anywhere in the body.
Right eye: Vision was reduced to hand movement. Projection of light was present. Ciliary injection was marked with moderate degree of edema of the lids. The cornea was clear, anterior chamber slightly deep; the iris was muddy in colour. The pupil was relatively small, irregular and occupied by albuminous exudate. There was a small hypopyon in the lower part of the anterior chamber. The eyeball was tender to touch and the intra-ocular tension was normal.
Slit-lamp examination revealed multiple posterior synechia with moderate degree of aqueous flare. A few keratic precipitates were present in the lower part of the cornea.
Left eye: Perfectly normal with 6/6 vision.
Total and differential counts were as follows:
W.B.C. - 19100 per cmm.
Polymorphs 48 per cent, Lympho 27 per cent, Eosino. 25 percent.
Red cells and platelet counts were normal.
Erythrocyte sedimentation rate was within normal limits. Examination of stool did not reveal any abnormality.
The patient was admitted to the hospital and treated as one of irridocyclitis with subconjunctival injections of strepto-penicillin and topical applications of atropine and hydrocortisone ointments. On the fourth day of admission, a small thread-like structure was noticed within the exudate in the pupillary area; it showed transient movement which was nicely seen with slit-lamp microscope. The eye was regularly examined with slit-lamp microscope and the parasite was found to come out of the exudate and fall into the lower part of the anterior chamber on 30-1.2-62. [Figure - 2]a and b.
In the meantime, the intra-ocular tension was slightly raised, for which tab Diamox (250 mg.) B.D. was administered. Within two days, the tension came down to normal. On 2-1-63, the parasite was removed from the anterior chamber under local anesthesia. A limbal keratome incision was made at 7 o' clock and the parasite removed with the help of an intracapsular forceps from the lower part of the anterior chamber. It was found to show active movements (visible with naked eyes) and was sent to the Helminthology department, School of Tropical Medicine, Calcutta for identification.
After removal of the parasite, the eye rapidly quietened down and the exudate in the pupillary area completely absorbed. The vision, although recovered considerably, remained below 6/60. Examination of the fundus showed diffuse vitreous haze and several linear whitish scars in the posterior region of the retina.
Janaki Nath Das, a young male aged 23 years was first examined in the eye Department, S.S.K.M. Hospital Calcutta on 24-12-62 with the complaint of severe pain in his left eye for 5 days. At the onset, he had headache, sickness and slight fever which lasted for 24 hours. There was considerable reduction of sight and redness in the affected eye.
His general condition was good; he was not running any temperature. His pulse, respiration and blood pressure were within normal limits. There were no evidences of skin lesion (subdermal nodules) anywhere in the body.
Right eye: Perfectly normal with 6/6 vision.
Left eye: Vision was reduced to hand movements. Projection of light was good. The eye was markedly congested (ciliary type) with moderate degree of lid swelling. The cornea was clear, anterior chamber slightly deep with iris muddy in colour. The pupil was small and contracted with irregular margins (posterior synechiae); the light reaction was very sluggish. The pupillary area was partly occupied by albuminous exudate. Intra-ocular pressure was within normal limits.
Slit-lamp examination showed multiple posterior synechiae with moderate degree of aqueous flare. Keratic precipitates were present.
The condition was diagnosed as irridocyclitis and the usual treatment recommended. After two days (26-12-62.) when he was again reviewed, a small curved thready structure was noticed in the pupillary exudate, the structure showed intermittent movements (visible with slit-lamp microscope). [Figure - 3]. He was admitted on the same day for investigation and further treatment.
Total and differential counts were as follow:
W.B.C. - 7800 per cmm.
Polymorphs. 56 per cent, lymph. 29 per cent., Mono. 1 per cent., Eosino. 14 per cent.
The counts for red cells and platelets were normal.
Urine and stool examination showed nothing abnormal. Erythrocyte sedimentation rate was within normal limits. X-ray chest revealed evidence of old pleural thickening on the right side.
The usual treatment of irridocyclitis, i.e. hot compresses, local atropine and hydrocortisone ointments, was continued and the eye condition reviewed daily. On the next day (27-12-62.), the pain in the eye increased and the cornea was found to be steamy with rise of intra-ocular pressure. Immediately, Tab. Diamox (250 mg.) B.D. was started and the tension carne down to normal within 24 hours.
On 28-12-62, the parasite was removed from the pupillary area under local anesthesia. A limbal keratome incision was made at 12 o' clock and the larva with some exudate was extracted with the help of an infra-capsular forceps. The specimen was sent to Helminthology department, School of Tropical Medicine, Calcutta for identification.
Post-operative recovery was uneventful and the eye quietened down quickly with gradual disappearance of the pupillary exudate. Ophthalmoscopic examination at this stage showed diffuse vitreous haze which prevented clear view of the fundus oculus. The vision gradually improved but remained below 6/60. After a few weeks, ophthalmoscopic examination was repeated when the vitreous opacities had reduced considerably and the fundus showed a pigmented patch just lateral to the upper temporal vessels about 2 disc diameter from the disc margin.
Morphology of removed larva:
The immature larvae removed from the anterior chamber of both the cases showed an identical picture. The worm measured approximately 3.5 mm. in length and 0.5 mm. in width. Under the microscope, the larva was actively moving and presented a cephalic bulb with 4 transverse rows of hooklets.
| Discussion|| |
These two cases have been reported because of the rarity of the condition and our ability to extract living gnathostome larva from the anterior chamber for identification. As far as our knowledge goes, Sen and Ghose  reported time first case of intra-ocular Gnathostomiasis from Calcutta in 1945. There are no reports of successful removal of living gnathostome larva from the anterior chamber. Unlike Sen and Ghose's case, there was no preceding inflammation of the orbital tissues (orbital cellulitis) or of the face in our cases. Apart from the ocular findings, no other clinical evidences of Gnathostoma infection were present elsewhere in the body.
How can gnathostome larva enter the anterior chamber? The parasite may have entered by burrowing through the ocular tissues in an attempt to get free. In Sen and Ghose's case, there was a scar below the macula which was thought to be the wound of entry, In our second case, a similar pigmented scar was found just lateral to the upper temporal vessels about 2 disc diameter from the disc margin. Another interesting finding in our cases was that the fundus showed linear whitish scars in the central region. The causation of these scars is not clear. They may represent the tract along which the larva might have migrated through the choroid before it finally burrowed the retina to reach the cavity of the eyeball.
What is the cause of irridocyclitis? It could be due to allergic reaction to an antigen liberated by the parasite or to mechanical irritation of the iris and ciliary body. Allergy may be the probable cause because in both the cases, there was associated eosinophilia.
| Summary|| |
Two cases of intra-ocular infection by immature Gnathostoma spinigerum are reported. The cases presented clinical picture of exudative irridocyclitis and living gnathostome larva were successfully removed from the anterior chamber.
The morphology of the adult parasites, their life cycle and pathogenicity are discussed in details.
| Acknowledgement|| |
Our thanks are due to Dr. A. B. Chowdhury, Department of Helminthology, School of Tropical Medicine, Calcutta for identifying the larva and Dr. I. S. Roy, Institute of Ophthalmology, Calcutta for photographing the larva in the anterior chamber in case no. 1.
| References|| |
Chatterjee, K. D. (1952) "Human Parasites and Parasitic Diseases", p. 561-562. Calcutta.
Sen. K., and Ghose. N. (1945) "Ocular Gnathostomiasis" Brit. J. Ophthal., 29, 618.
Sorsby, A. "Systemic Ophthalmology" 2nd Ed. p. 257 Butterworth & Co., London (1958)
[Figure - 1], [Figure - 2], [Figure - 3]