Unusual Presentation of Subretinal Cysticercosis With Hypopyon Uveitis

Introduction

Cysticercosis, caused by the encystment of the larvae of Taenia solium, is the most common ocular platyhelminth infestation in humans.¹ Ocular cysticercosis can be subconjunctival, intraocular, orbital, or in the eyelids.² Intraocular cysticercus may occur in the anterior chamber or an intravitreal or subretinal location. As expected with an inflammatory process predominantly involving the posterior segment, subretinal cysticercosis usually produces only mild anterior segment inflammation. We report an unusual case of subretinal cysticercosis in a child presenting with severe anterior uveitis and hypopyon, associated with dense vitritis and retinal detachment.

Case Report

A 7-year-old boy presented with redness and pain in the right eye for 7 weeks. There was no positive systemic history. He was treated with topical steroids elsewhere. Because there was no symptomatic improvement, the child was brought to our center.

At presentation, the visual acuity in the right eye was hand motions close to face with inaccurate projection of light in two quadrants. The right eye was exotropic with dense anterior segment inflammation, hypopyon, and posterior synechiae (Figure 1). Relative afferent pupillary defect was present and intraocular pressure was 4 mm Hg. The lens was clear. He also had dense vitritis with no view to the fundus. The left eye was normal with visual acuity of 20/20.

Figure 1. Slit-lamp photography showing white reflex and posterior synechiae.

B-scan ultrasonography of the right eye showed a cystic lesion (Figure 2) that had an eccentric, highly reflective echo suggestive of scolex, with associated retinal detachment. Vitreous had multiple echoes suggestive of dense vitritis. Magnetic resonance imaging (MRI) of the orbit and brain were done to rule out orbital cysticercosis and neurocysticercosis. MRI showed an approximately 8-mm single, well-defined, hyperintense, spherical lesion in the superotemporal quadrant of the right eye (Figure 3) with an eccentric, hypointense focus (on T2-weighted images) representing the scolex. Total retinal detachment was noted with subretinal fluid collection. There were no orbital or intracerebral lesions. Based on these findings, a diagnosis of subretinal cysticercosis with associated total retinal detachment in the right eye was made. Because B-scan and MRI were suggestive of cysticercosis, further investigations were not considered.

Figure 2. Ultrasound biomicroscopy showing a cystic lesion (thick arrow) with scolex (thin arrow) and retinal detachment (double arrow).

Figure 3. T2-weighted magnetic resonance imaging showing a hyperintense lesion (white arrow) in the superotemporal quadrant of right eye with hypointense focus (black arrow) representing the scolex. Curved arrow indicates subretinal fluid.

Surgery was deferred after a detailed discussion with the child’s parents because the prognosis for visual acuity was poor. He was treated conservatively with topical steroids, cycloplegics, antihelminthics (oral albendazole 15 mg/kg/day in two divided doses for 6 weeks) and systemic corticosteroids (prednisolone 1 mg/kg/day). The patient was asymptomatic after a few days of treatment; however, there was no improvement in visual acuity.

Discussion

Ocular cysticercosis can be subconjunctival, intraocular, orbital, or in the eyelids. Intravitreal and subretinal cysticercosis can present with decreased visual acuity, pain, redness, and floaters with signs of mild anterior uveitis, severe vitritis, and retinal detachment.¹ Severe anterior chamber fibrinous reaction has been reported in a child with anterior chamber cysticercosis.³ However, severe anterior chamber reaction with hypopyon in subretinal cysticercosis has not been reported. Delay in diagnosis and management could be the reason for such severe inflammatory reaction in the anterior chamber in our patient.

Subretinal and intravitreal cysticercosis can be diagnosed by ophthalmoscopic examination in the presence of clear media. In the presence of hazy media due to dense inflammatory reaction, B-scan ultrasonography, computed tomography, and MRI are imaging modalities that aid in the diagnosis of ocular cysticercosis. In our patient, B-scan showed the typical cyst with an eccentric, echogenic scolex, suggesting cysticercosis. MRI can be an adjunct to B-scan and is superior to computed tomography in ocular cysticercosis.⁴ In our patient, a cystic lesion with an eccentric echo in the subretinal space was also seen on the MRI images, confirming subretinal cysticercosis. MRI also helped to exclude orbital cysticercosis and neurocysticercosis.

Surgical intervention is the treatment of choice in subretinal cysticercosis and should be done at an early stage by removing the cyst either transsclerally or transvitreally. However, this may be associated with intraoperative complications such as hemorrhage, cyst rupture, and iatrogenic breaks.¹ Due to the delay in presentation, this patient had inaccurate projection of light, relative afferent pupillary defect, hypotony, dense vitritis with inflammatory membranes, and retinal detachment. The prognosis and complications of surgical treatment were discussed with the parents and surgery was deferred.

Systemic antihelminthics are generally not advocated for the treatment of subretinal cysticercosis because they can cause death of the parasite with release of toxins, resulting in severe inflammation. Because our patient had poor visual acuity, we decided to treat him with oral albendazole to destroy any other possible sites of infestation. This was given under cover of systemic corticosteroids and we did not note any increase in inflammatory reaction while receiving treatment.

Subretinal cysticercosis can rarely present with severe anterior chamber reaction and hypopyon. This may suggest a longstanding infestation. Early diagnosis is mandatory for good visual outcome in these cases. Prompt imaging with B-scan ultrasonography and MRI can help confirm the diagnosis when dense inflammatory reaction precludes adequate visualization of the posterior segment. Timely diagnosis of the condition would facilitate early institution of appropriate therapy and prevent permanent visual loss.