|Year : 1977 | Volume
| Issue : 4 | Page : 43-45
Anna Thomas, Molly Mathew Oommen, TA Alexander
Department of Ophthalmology, Christian Medical College, Vellore, India
Department of Ophthalmology, Christian Medical College Vellore-632 001
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Thomas A, Oommen MM, Alexander T A. Intraocular filariasis. Indian J Ophthalmol 1977;25:43-5
In the last twentyeight years in the department of ophthalmology we have come across various ocular manifestations due to parasitic invasion of the eye and the ocular adnexa. This included besides namatodes, dracunculus medinensis and ancylostoma duodenale, cestodes and protozoa.
Since 1968 when we came across a case where innumerable live microfilaria were found stuck to the crystalline lens in both eyes with bilateral uveitis, we were on the look out for cases of intraocular filariasis. Since then we came across two more cases of filarial infestation with ocular manifestations.
| Case Report I|| |
Mr. G. a Hindu male aged 25 years resident of Walajah Taluk, Tamilnadu, South India came to the outpatient department on 18th February 1976 complaining of decreased vision in the left eye of 4 days duration. On examination his vision in the right eye was 6/6 and that of left eye was counting fingers at 80 cms. On biomicroscopic examination cells were detected in the vitreous of the left eye. Fundus examination revealed a hazy media, with blurred disc margins and a worm stuck to the retina attached to the superior temporal vessels. It showed a constant burrowing movement at the superior end on directing the light from the ophthalmoscope on it. Since his night blood smear showed numerous microfilaria Wuchereria bancrofti it was assumed that the worm in the fundus was microfilaria wuchereria bancrofti. The day blood taken for WBC count also showed numerous microfilaria. After seeing the laboratory report, we elicited a history of fever with chills of one months duration.
The patient also showed E. histolytica in the stools which was treated with Emdequin.
As soon as treatment with Hetrazan was started the movement of the worm stopped, lost its grip on the retina, slided down to cover the macula and slowly disintegrated forming vacuoles fragmenting within a month. On subsequent visits pallor of disc was noticed showing commencing optic atrophy. On his last visit on 28th September 1976 the vitreous showed no cells and four flattened white pieces were seen on the retina near the macular region remnants of the worm Wuchereria bancrofti. There was also optic atrophy and pigment disturbance of macula. Vision had improved to 6/60 from counting fingers and remained stationary thereafter.
| Case Report II|| |
Mr. S. a Hindu male aged 28 years from Gudiyattam (Tamilnadu) came to us in July 1975 with diminution of vision of one week duration. On examination his vision was 6 / 18 and 6/12 in the right and left eye for distance and Jl for near in both eyes. Slit lamp examination revealed a bilateral uveitis and the right fundus showed exudates. Routine laboratory tests were taken and patient treated with local and systemic steroids and atropine to which he responded well. But again he came back in February 1976 with a recurrence of uveitis, when some investigations were repeated and microfilaria Wuchereria bancrofti was seen in night blood, on 3 consecutive occasions. He was treated with Hatrazan and local and systemic steroids. He improved considerably and in August 1976 on his last visit the vision was 6/6 and J 1 for distance and near in each eye. Fundus showed few residual vitreous floaters.
| Discussion|| |
According to Duke Elder  the incidence of intraocular filariasis is rare but common in animals. Though only a few reports of intraocular filariasis in man are found in the literature, the incidence may not be as rare as made out, since few take the trouble to report their cases. Another reason is that the presenting symptoms are usually that of iritis and this etiology is not usually looked for in that disease. Rose,  advised to look for filariasis in all cases of uveitis in tropics where it is endemic.
In all reported cases the microfilaria were found in the anterior chamber or when present in the vitreous chamber they eventually found their way into the anterior chamber.
Madangopal  cites a case presented by Mody et al where a worm probably filaria which was found near the macula migrated into the anterior chamber on applying a beam of photocoagulation.
Kerkenezov  mentions in his case of intraocular filariasis no other clinical symptoms, no temperature rise, no eosinophilia or microfilaria in peripheral blood on repeated examination by day and night. It is suggested the worm enters the eye through its outer coat or through a venous channel in the absence of ocular lymphatics.
In Misra's case  the intravitreal worm was found opposite the macular area, one end seemed to be attached to the retina. Later the worm entered the vitreous, swimming about freely. In one case reported here, the worm was found to be attached at the macula the other end was moving and after death it was still stuck to the retina. In an earlier case reported by Thomas et al  numerous microfilaria were found clinging to the lens capsule with the curved end of the sheath present in microfilaria Wuchereria bancrofti. The same mechanism can explain how the worms are found clinging to the retina. It is interesting that in all these cases the worm was found on and around the macular region. Sorsby  gives gross chorioretinitis associated with consecutive optic atrophy as one of the complications of filariasis. He also mentions that sometimes optic atrophy can be found in the absence of chorioretinal changes. The first case reported here presented as optic neuritis. He developed optic atrophy and showed two chorioretinitis patches in the upper and lower temporal peripheral fundus. The optic neuritis was probably due to irritation caused by the live worm and due to toxins liberated after the death of the worm.
We want to stress that in the tropics where filariasis is endemic it may be worthwhile to rule out filariasis in all cases of uveitis and optic neuritis of obscure etiology.
| Summary|| |
Two cases of ocular manifestation of microfilaria are reported. One case presented as optic neuritis in which the worm was found to be attached to the retina. The other case presented as uveitis with microfilaria in the peripheral blood and responded to therapy with hetrazan. In tropical countries where the disease is endemic, this etiology should be looked for in all cases of uveitis.
| References|| |
Barrada, 1934, Bull. O.S. Egypt XXVII, 63
cited by Duke Elder.
Duke Elder, S., 1940, Text book of Ophthalmology, 3,
Kerkenezov, N., 1962, Brit. J. Ophthal., 46
Kuhnt, A.F., 1892, Aug. XXIV 205 cited by Duke Elder.
Madangopal, A.V., 1970, Proc. 1411 India Ophthal. Soc. XXXI,
Misra, S., 1958, Arch. Ophthal., 60,
Nayar, and Pillai, 1932, Brit. J. Ophthal., 16,
549 cited by Duke Elder.
Rose, L., 1966, Arch. Ophthal. 75, 13.
Sorsby, A., 1972, Modern Ophthal.,
2nd ed. 2, 218, 227.
Thomas, A. et al,
1974, Eas. Arch. Ophthal., 2,
[Figure - 1], [Figure - 2]