Cysticercosis of the optic nerve

Cysticercosis in ophthalmology

Cysticercosis is caused by Taenia solium, a cestode or tapeworm that preferentially affects the subcutaneous tissue, brain, muscle, and the eye. It is traditionally a disease of low socioeconomic regions, but large-scale population migration has made it a matter of global concern. Its ocular invasion is a potentially blinding disease. In the last two decades, there has been considerable discussion of cysticercosis; however, most comes from a limited number of case observations. Thus, to overcome this limitation, we summarize and analyse twenty years of medical literature (from 2000 to 2020) on cysticercosis in ophthalmology.

Minimally invasive bone-saving orbitotomy for removal of optic nerve cysticercosis

A 32-year-old man previously being managed for multiple neurocysticercosis presented with a reduction in vision and pain on eye movement. Fundus examination revealed disc edema with venous dilatation. MRI showed a localized hypointensity on T1 weighted images and hyperintensity on T2 weighted images suggestive of a cyst in the optic nerve sheath. Medical therapy with albendazole and steroids did not improve vision. Surgical removal of the cyst was achieved by a modified lateral orbital exploration using a lateral canthal incision without bone removal, with full recovery of vision. Histopathological examination confirmed cysticercosis.

Retrobulbar cysticercosis masquerading as optic nerve glioma

Extra ocular muscles are the most common site of involvement in orbital cysticercosis. We present a case of retrobulbar cysticercosis masquerading clinically as optic nerve glioma.

Optic nerve cysticercosis: case report and review of current management

The authors present a case of optic nerve cysticercosis in a 32-year-old patient who presented with sudden blurring of vision in the left eye and a transient visual improvement on systemic steroids. The ocular findings were unremarkable other than a relative afferent pupillary defect (RAPD). An ultrasound of the orbit, CT and MRI scans revealed a cystic lesion in the orbital portion of the optic nerve close to the eyeball. A presumed diagnosis of optic nerve cysticercosis was made on the basis of imaging and a positive serum ELISA. The patient improved dramatically on a 4-week therapeutic trial of albendazole and oral steroids. The post-treatment ultrasound and CT scan showed an involution of the cyst with some residual thickening of the optic nerve.

Optic nerve cysticercosis

Optic nerve cysticercosis is rare but causes significant visual morbidity. A high index of suspicion is warranted for patients in endemic areas who present with sudden vision loss. Visual morbidity can be prevented by early imaging studies and therapeutic interventions.

Orbital and adnexal cysticercosis

Orbital and adnexal cysticercosis is emerging as a far commoner disease than previously considered, both in endemic and nonendemic areas of cysticercosis. A review of the literature on orbital and adnexal cysticercosis found that it has a predilection for children and young adults with no definite sex predilection. The extraocular muscle form is the commonest type of orbital and adnexal cysticercosis. Lodgement of cysts in the subconjunctival space is another common site, followed by the eyelid, optic nerve, retro-orbital space and lacrimal gland. Association of orbital cysticercosis with systemic cysticercosis is quite rare. The clinical manifestations of orbital or adnexal cysticercosis are entirely different and depend on the location, size, relation to adjacent structures and stage of evolution of the cyst. Diagnosis of cysticercosis is based mainly on orbital imaging because of its highly specific appearance. Tissue diagnosis is not essential for initiating treatment. Medical therapy is the recommended treatment for the extraocular muscle form and retro-orbital cysticer-cosis. Surgical removal is advocated for subconjunctival and eyelid cysticercosis. Because of the limited number of cases of optic nerve and lacrimal gland cysticercosis, their treatment is controversial.

Optic nerve cysticercosis

Cysticercosis of the optic nerve is an extremely rare entity and only seven cases have been reported in the world literature. A case of optic nerve cysticercosis in a 25-year-old woman is reported, along with a review of literature. The patient presented with two episodes of pain, diminution of vision and proptosis. Computed tomography and ultrasonography revealed an intraneural cyst with scolex in the retrobulbar portion of the optic nerve. A positive enzyme-linked immunosorbent assay test for cysticercosis further confirmed the diagnosis. Medical therapy in the form of oral albendazole and steroids resulted in complete resolution of the cyst, with few visual sequelae.

Bilateral cysticercosis of the optic nerve

Bilateral cysticercosis of the optic nerves affected a man who presented with features suggestive of optic neuritis. Ultrasonography revealed bilateral sonolucent cystic lesions with central echo-dense, highly reflective structures behind the optic nerve heads. A subretinal cyst was present in one eye. Magnetic resonance imaging of the brain and orbit revealed multiple cysticerci in the brain, orbit, and eye. The subretinal cyst was removed by pars plana vitrectomy, and the other cysts resolved on treatment with albendazole.

Ocular and orbital cysticercosis

PURPOSE

To study the demographic factors, clinical diagnosis, results of investigation, modalities of treatment and their outcome in ocular and extraocular cysticercosis.

METHOD

A total of 20 patients were recruited for the study. Ultrasonography and computed tomography were done for all the patients. Serial ultrasound was obtained in patients receiving medical treatment. Therapy was individualized according to the location of the cyst.

RESULTS

The commonest clinical presentation was proptosis (9 of 20) with restriction of ocular movements, followed by subconjunctival cyst, subretinal cyst, papilloedema, atypical optic neuritis, lid nodule and intraretinal cyst. Ultrasonography was comparable with computed tomographic scan for detection of scolex. Two of the twenty patients had associated cysts in the brain parenchyma. Medical or surgical therapy as indicated, had a satisfactory outcome.

CONCLUSION

Cysticerci can lodge themselves in any part of the ocular and extra ocular tissue. Associated brain parenchyma involvement is quite rare. The clinical presentation, treatment and outcome mainly depends on the location of the cyst.