Multifocal cysticercosis with optical coherence tomography findings in a child.

We herein report a case with multifocal cysticercosis--sub-conjunctival cysticercus cyst, sub-retinal cysticercosis, and neurocysticercosis in a child. The optical coherence tomography (OCT) findings of the sub-retinal cysticercus cyst are reported. He was treated with anti-helminthic drugs and oral prednisolone followed by surgical removal of the sub-retinal cyst. He subsequently underwent silicone oil removal with lens aspiration and intraocular lens implantation maintaining stable vision.

INTRODUCTION

Cysticercosis is the infestation by Cysticercus cellulosae, the larval form of the pork tape worm, Taenia solium. It is contracted by ingestion of under-cooked pork, contaminated water or vegetables. The sites for predilection for the development of cysticerci are the central nervous system (CNS), sub-cutaneous tissue, skeletal muscles, the heart muscle and the eye.12 Ocular cysticercosis is common in the Indian sub-continent.3 We report a case of multifocal cysticercosis in a male patient and present the optical coherence tomography (OCT) findings of the sub-retinal cysticercus cyst.

CASE REPORT

A fourteen-year-old male presented with decreased vision in the right eye for one month and a cyst-like lesion in the left eye for the same duration. There was no history of headache or seizures. He was a vegetarian. On examination, the best corrected visual acuity(BCVA) in the right eye was 1/60, < N36 and in the left eye 6/6, N6. Slit lamp examination of the right eye showed a clear lens with no anterior chamber or vitreous reaction and the left eye showed a subconjunctival cyst near the outer canthus [Figure 1a]. Intraocular pressure was 14 mm of Hg bilaterally. Fundus examination of the right eye revealed an elevated retina along the inferotemporal arcade with an underlying cyst and surrounding chorioretinal atrophy extending into the macular area [Figure 2]. The fundus of the left eye was normal.

Figure 1a

Subconjunctival cysticercus cyst near the outer canthus of the left eye

Figure 2

Color fundus photograph of the right eye showing elevated retina along the inferotemporal arcade with an underlying cyst and surrounding chorioretinal atrophy extending into the macular area

Ultrasound B-scan of the right eye showed a dome-shaped highly reflective immobile membrane in the infero-temporal quadrant suggestive of retinal detachment and a hypoechoic area with a high reflective center in the sub-retinal space suggestive of a scolex [Figure 3]. OCT of the right eye showed hyper-reflective dome-shaped band with a hypoechoic space and a hyperechoic clump in the center suggestive of cysticercus cyst encasing a scolex. This correlated clinically with the subretinal cyst seen on fundus examination [Figure 4]. The underlying retinal pigment epithelium could not be imaged because of the increased height of the cyst. Computed tomography (CT) scan of the brain showed multiple cerebral and cerebellar neurocysticercus lesions [Figure 5].

Figure 3

Ultrasound B-scan of the right eye showing a dome-shaped highly reflective membrane suggestive of retinal detachment and a hypo-echoic area with a high reflective center in the subretinal space suggestive of a scolex

Figure 4

Spectral domain optical coherence tomography of the right eye showing hyper-reflective dome-shaped band with a hypoechoic space and a hyperechoic clump in the center suggestive of cysticercus cyst with scolex

Figure 5

(a) Computed tomography scan of the brain showing multiple cerebral and cerebellar neurocysticercus lesions (b) Computed tomography scan of the brain showing multiple cerebral and cerebellar neurocysticercus lesions (White arrows)

The patient was treated with oral albendazole 15 mg/kg and a tapering dose of oral prednisolone- 1.5 mg/kg prior to pars plana vitrectomy (PPV). After two weeks of treatment, the child presented with acute rhinorrhea, wheezing, breathlessness, bronchospasm and circumcorneal congestion of the right eye suggestive of an anaphylactic reaction which was treated with oral and topical prednisolone and a steroid inhaler. Subsequently, the patient underwent PPV, retinotomy over the cyst, piecemeal removal of the cyst, fluid air exchange, laser photocoagulation and silicone oil tamponade under general anesthesia. Informed consent was obtained from the parents prior to surgery.

The vitrectomy material was sent for histopathological examination which showed variable degenerate parasite suggestive of cysticercus cellulosae. At two months follow up, the BCVA of the right eye was 1/60, < N36. Fundus examination showed persistent focal elevation of the retina for two months and then it flattened spontaneously.

At three months follow-up, the patient presented with pain and redness in the right eye and BCVA of counting fingers at 1 m, < N36. Slit lamp examination indicated an inverted hypopyon in the anterior chamber due to early emulsification of the silicone oil and lenticular changes. The intraocular pressure was 26 mmHg in the right eye. The retina remained attached throughout with emulsified silicone in situ. Anti-glaucoma medication was prescribed and silicone oil removal in the right eye was scheduled. There was a spontaneous resolution of the subconjunctival cysticercus cyst in the left eye [Figure 1b].

Figure 1b

Spontaneous resolution of the subconjunctival cyst after anti-helminthic treatment

DISCUSSION

Cysticerci infection can be extraocular or intraocular.4 In our case, the parasite presumably gained access through the posterior ciliary arteries and therefore was found near the posterior pole in the subretinal space. It caused a localized retinal detachment which was limited by the chorioretinal scar formation secondary to inflammation.

In the current case, neurocysticercosis was initially treated with oral prednisolone followed by oral albendazole.5 After two weeks of therapy, the child developed marked inflammatory response to the toxic products released from the cyst leading to acute rhinorrhea, circumcorneal congestion of eyes with lacrimation, congestion of posterior pharyngeal wall and auscultation of the chest revealed bilateral intense bronchospasm. This caused a further delay in obtaining a clearance for general anesthesia and surgery. Intraoperatively, there was extensive reaction in the vitreous cavity and the cyst came out piecemeal through the retinotomy. Inflammation caused early silicone oil emulsification.

OCT of the sub-retinal cysticercus cyst showed serous detachment of the retina, where the cyst wall could not be separately appreciated in our case. This was likely due to adhesion to the undersurface of the detached retina. This resembled the OCT picture of chronic central serous retinopathy where there are few high reflective echoes under the detached retina due to subretinal precipitates but they are not so well defined like a round clump of high reflective echoes suggestive of the scolex. We were unable to appreciate any breaks in the retinal pigment epithelial – choriocapillary complex which may have provided some insight into the pathway of parasite into the sub-retinal space.

This case highlights that despite the presence of neurocysticercosis, the removal of the subretinal cyst should be performed prior to the initiating oral anti-helminthic drugs. As the cysticercus parasites die, toxins are released that cause a severe inflammatory response making the surgery more complicated. If there is a history of seizures, then anti-epileptic drugs maybe warranted prior to surgery. To the best of our knowledge, this is the first case report describing OCT findings of a cysticercus cyst.