Socio-demographic trends in ocular cysticercosis

- ACTAOPHTHALMOLOGICA SCANDINAVICA 1995

Socio-demographic trends .. in ocular cysticercosis 0

1

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Kumar Atul, Tewari Hem Kumar, Goyal Mallika and Mitra Sandip Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India

ABSTRACT. There has been a gradual change in the socio-demographic trends of ocular/adnexal cysticerosis. We present the results of a 5-year study of 33 cases of ocular/adnexal cysticercosis and compare our observations with those reported by previous authors. The ma1e:female ratio in our study was 2:l and maximum number of patients (45%)belonged to the age-group of 31-40 years. Seventy percent of our patients were of low socio-economic status and 70%were strictly vegetarians. The most common location of cysticerci was in the vitreous (50%of all cases); orbital cysts were present in 5%and subconjunctival cyst in 3%. Most common extraocularsite for associated cysticercosiswas the brain (18%):Ultrasonography proved to be an effective and economical alternative to magnetic resonance imaging and computerized tomographic scanning for the detection of cysticerci in the orbit and in eyes with hazy media. Key words: socio-demographic - cysticercosis - intravitreal- subretinal - orbital. Acta Ophthalmol. Scand. 1995: 73:438-441

C

ysticercosis is the infestation by Cysticercus cellulosae, the larval form of the tapeworm, Taenia solium. In the normal course of the life-cycle of this tapeworm, pig is the intermediate host and man is the definitive host, however, man may accidentally become the intermediate host by ingestion of pork or faecally contaminated vegetables, water or by auto-infection. This parasite is endemic in various parts of the world, including Mexico, Africa, S.E. Asia, Eastern Europe, Central and South America and India (Cano 1989).Since the first cysticercus seen in the human eye by Soemmering in 1830, and extracted by Schott in 1836 (Cano 1989), the epidemiological status has considerably changes along with its location in various ocular 438

sites. We report a 5-year study of 33 patients with ocular and adnexal cysticercosis where we analysed its epidemiological status and clinical presentation.

variables - education, occupation and income. Each item is assigned a specific score so that the status-score of an individual can be objectively worked out; a score of less than 10 is suggestive of low socio-economic status. Detaded ophthalmological examination including visual acuity recording, slit-lamp biomicroscopy, direct ophthalmoscopy and indirect ophthalmoscopy were performed for each eye studied. In cases where media were hazy or where we suspected subretinal extension of an intravitreal cyst or in cases for orbital evaluation, we performed ultrasonography (both A-scan and B-scan) using the Ophthascan-S machine piophysic Inc.). Laboratory investigations for each patient included stool examination for ova and cysts, E.S.R., total and differential leucocyte count and absolute eosinophil count. Patients were examined by general physician to detect cysticerci localised in other parts of the body and by a neurologist to rule out neurocysticercosis. Neurological evaluation included computerized tomography in each case.

Material and Methods We evaluated 33 eyes with suspected ocular or adnexal cysticercosis from the out-patient department of our hospital during the period from 1989 to 1933. Record was made of the age, sex, presenting complaints, dietary habits and socio-economic status of each patient. The socio-economic status was determined using Kuppuswamy’s socio-economic status scale (Kuppuswamy 1962) which containts seven items in each of the following three

Results Of the 33 cases of clinically confirmed cysticercosis, 22 patients were male and 11 were female, making the ma1e:female ratio 2:l. Age range of our patients was from 8 to 60 years with 45% of the patients belonging to the age-group of 31-40 years (Table 1). Seventy percent of our patients had a low socio-economic status and were ignorant of the importance of washing

ACTAOPHTHALMOLOGICA SCANDINAVICA 1995 Table 1. Age and sex distribution of patients in the present series.

0 - 10

1

21 - 3 0 31 - 4 0 > 40

1 2 7 10 2

3 5 2

2 2 10 15 4

Total

22

11

33

11 - 2 0

fruits and vegetables before consumption. Seventypercent of our patients were vegetarian and 30% were non-vegetarian; of the non-vegetarian, only 10% volunteered a definite history of pork intake. The most common presenting complaint was loss of vision, painless in 21 patients (63%), but associated with pain in 4 patients (12%). Six patients (18%) presented with non-axial proptosis accompanied by restriction of ocular movements. One patient (3%) presented with conjunctival injection, chemosis and a sub-conjunctivalswelling which was later proven to be cysticercus on histopathological examination. A 5-year-old boy presented with leucocoria and a presumptive diagnosis of metastatic endophthalmitis had been made; ultrasonic evaluation revealed the intravitreal cysticercus. As shown in Table 2, the most common location for ocular or adnexal cysticerci was in the vitreous (54% of all cases) followed in order by the orbit (18%) and the subretinal space (150/,).

Sub-conjunctival cyst was present in only one case (3%) in our series. The left eye/orbit was involved in 21 (63%) of the 33 cases that we studied; the deviation of this value from 50% is not statistically significant (p > 0.05; Z-proportion test). Six cases (18%) had associated neurocysticercosis - only two of these presented with generalized seizures. The computerized tomographic picture in all these cases was typical of neurocysticercosis. Interestingly, all patients with neurocysticerci in our series had intravitreal cysts. General physical examination did not reveal cysticerci in the subcutaneous tissue, muscles or liver of any patient. All laboratory reports were within normal limits, stool was negative for ova and cysts in all cases studied.

Discussion Since 1836, when Schott and Soemmerring discovered a live cyst in the anterior chamber (Anderson 1966) the epidemiological picture of ocular and adnexal cysticercosis appears to have changed considerably.This study conducted over a period of 5 years attempts to present anupdate on the current socio-demographictrends of ocular and adnexal cysticercosis. There was a definite male preponderance in our study with the ma1e:female ratio being 2:l; a similar male preponderance has been reported in only one other study by Reddy & Satyendran (1964). Most other studies

have found no predilection for either sex (Can0 1989; Duke-Elder & Perkins 1966; Lech 1949; Malik et al. 1968;Reddy et al. 1980). Maximumnumber of patients in our series belonged to the age-group of 3140 years. Most other authors have reported this disease in a younger agegroup. Reddy & Satyendran (1964) reported that 90% of their patients were less than 15 years of age; Reddy et al. (1980) further found that 52.8% of their patients were less than 15years of age; Malik et al. (1968) reported that 68% of their patients were in the agegroup of 10-30 years. Seventy percent of our patients were from a low socio-economic status group and were found to be ignorant of the importance of washing fruits and vegetables before consumption. No comment regarding this factor was found on review of the literature. Seventy percent of the patients were strict vegetarians and 30% were nonvegetarians. Hence, it can be assumed that the most common mode of transmission was vegetables, fruits and salads contaminated with tapeworm ova and similarly contaminated water. In our series, the most common location of ocular/adnexal cysticerciwas in the vitreous (54% of allcases, Fig. 1) followed in order by the orbit (18%) and the subretinal space (15%); subconjunctival cyst was detected in only one eye (3%) of the 33 eyes that we studied. Similar localizationof ocular cysticercosis has been reported by most western workers including von Graefe (1866), Vosgien (1912), and KrugerLeite et al. (1985). However, Reddy &

Table 2. Location of ocular/adnexal cysticerci in different series.

Site Lids Subconjunctival Orbital Anterior chamber Lens Subretinal Vitreous Communicating (subretinal & vitreous) Optic nerve Scleral Total

This series (1994)

Graefe (1866)

Vosgien (1911)

Laignier (1932)

Lech (1949)

Reddy et al. (1964)

1 6

5 1 3 1

84

7

6 1

20

1

7 1 2

162

26

105

2

Sen et al. (1967)

Rao et al. (1967)

Malik et al. (1968)

9

13 1

10 1

1

1

1

5 18 3

80

1

1

2 1

33

90

266

35

115

10

11

15

14

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- ACTAOPHTHALMOLOGICA SCANDLNAVICA 1995

Fig. 1. Ophthalmoscopic view of intravitreal cysticercus.

Satyendran (1964) found that 60% of the patients in their series had subconjunctival cysticerci (Table 2). Malik et al. (1968) reported subconjunctival cysticerci in 10 out of 12 cases and Reddy et al. (1980) detected subconjunctival cysts in 13 out of 15 patients, with the other 2 patients having cystsin the eyelids. Sen & Thomas (1969) also found that the most common site for ocular cysticerci was in the subconjunctival space. To summarize, heretofore there has been a dichotomy in the reports from the West and those from Lndia regarding the location of cysts in the eye or its adnexa; however, in our series the localization of ocular cysts is in agreement with that reported by most western authors till date. Interestingly, we also found 2 cases of com-

municating (vitreal and subretinal) cysticerci which we have reported earlier Kumar et al. (1989) (Fig. 2). The left eye or orbit was involved in 21 (63%) out of the 33 cases that we studied; though the deviation of this value 50% is not statistically significant (p > 0.05; Z-proportion test), a similar trend has been observed earlier. Reddy & Satyendran (1964) observed that the left eye or orbit was involved in 80% of their cases; Malik et al. (1968) also reported left side involvement in 75% of their cases. Similar observation was made by Rao et al. (1967) and by Sen et al. (1967). This predilection of the left side is explained by the more direct course of the left internal carotid artery from its origin at the aorta.

Fig. 3. Ultrasonographic picture of an orbital cysticercus.

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Fig. 2. Ultrasonographic picture of a communicating (vitreal and subretinal cyscticercus.

In this series, orbital cysticercosis was present in 6 (18%) out of the 33 cases of ocular or adnexal cysticercosis. This contrasts with previous reports where von Graefe (1866) observed one (1.1./0) case of orbital involvement among the 90 cases he studied, Vosgien (1912) found no case out of the 372 cases he evaluated, Lech (1949) documented orbital involvement in 2 (1.8%) of 111cases of ocular/ adnexal cysticercosis and Toluant (1969) reported this in only 19 (4.1%) of 462 cases. Of the 6 patients with orbital involvement, all presented with proptosis painless in 4 and associated with pain and diplopia in 2. Diagnosis was confirmed by ultrasonic evaluation of clincially suspected cases.

Fig. 4. Ultrasonographic picture of an intravitreal cyscticercus in an eye with hazy media.

ACTAOPHTHALMOLOGICA SCANDINAVICA 1995 The most common extraocular site for cysticerci in our series was the brain. Definite computerized tomographic evidence of neurocysticercosis was present in 6 (18') of 33 cases. This is in agreement with the observation of Walsh (1957), but in conflict with the report by Malik et al. (1968) where subcutaneous tissue was the most commonly involved site (24.5% of all cases) followed in order by the brain (13.6%) and the eye (l2.8%). Similarly,Anderson (1966) and Reddy et al. (1980)found cysticerci to be most commonly present in the subcutaneous tissue. The hgher incidence of cerebral cysticercosisin our series can be explained by the fact that all patients were screened with computerized tomographic scan of the head, enabling the sub-clinical cases to be picked up; most of such cases would have been missed in the previous clincal studies reported. Interestingly, atl patients with neurocysticerci in this series had intraocular cysticerci and none had orbital cysts. This may be explainedby the fact that orbital blood-supply is at least partly through the branches of the muscular arteries that offer greater resistance to blood flow than do the posterior ciliary arteries supplying the choroid and causing intraocular cysticercosis. None of our patients had significant eosinophilia.This is in agreement with most other reports except that of Reddy et al. (1980) which documented eosiniphiliain66.6% of allcases. Stool was negative for ova and cysts in all cases.

We also found ultrasonography to be indispensable for the diagnosis of orbital cysticerci (Fig. 3), intraocular cysticerci with hazy media (Fig. 4)and subretinalcysticerci.As reported by us early (Murthy et al. 1990)it is a reliable and more economical than the more sophisticated investigative modalities like computerized tomography and magnetic resonance imaging for the diagnosis of these conditions. Indeed, the use of this modality in this series may explain why the locations have changed in clinical series - previously, diagnoses of ocular/orbital cysticercosis were presumptive more often, or had to be ignored due to lack of any specific clinical features combined with the absence of demonstration of the cysts by appropriate noninvasive methods.

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Lech (1949): Ocular cysticercosis. Am J Ophthalmol32: 523. Ma& S R K, Gupta A K & Choudhry S (1968): Ocular cysticercosis. Am J Ophthalmol57: 664. Murthy H, Kumar A & Verma L (1990):Orbital cysticercosis - an ultrasonic diagnosis. Acta Ophthalmol (Copenh) 68: 612-614. Rao N & Balakrishnan E (1967): Cysticercosis of the eye. Orient Arch Ophthalmol 5: 249. Reddy M, Satyendran 0 M & Sivaramalrishna K (1980): Ocular cysticercosis.Indian J Ophthalmol28: 69-72. Reddy P S & Satyendran 0 M (1964): Ocular cysticercosis. Am J Ophthalmol 57: 664. Sen D K, Mathur R N & Thomas A (1967): Ocular cysticercosis in India. Br J Ophthalmol51: 630. Sen D K & Thomas A (1969): Incidence of sub-conjunctivalcysticercosis.Acta Ophthalmol (Copenh) 57: 395-399. Toulant P (1969): Quoted by Walsh. Clinical Neuroophthalmol, Vol II. Williams and Wilkins,Baltimore. Vosgien I (1912): Le cercus cellulosae chez l'home et chez les animaux.Bull SOCCentr Med Vet 12: 270. Von Graefe (1866): A Bemerkung uber cysticerosis. Acta Ophthalmol (Copenh) 12: 174. Walsh F B (1957): Clinical neuroophthalmology, ed 2, p 532. Williams and Wilkins, Baltimore. ~~

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Received on July 29th, 1994. Correspondingauthor: Dr. Atul Kumar (associate professor) Dr. Rajendra Prasad Centre for Ophthalmic Sciences AU India Institute of Medical Sciences New Delhi, 110029,India.

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