Behind the Eye: Exploring the Threat of Subconjunctival Cysticercosis

Abstract

This report presents a rare case of a 25-year-old man with a Taenia solium worm found under the conjunctiva of his left eye. The patient had experienced redness, pain, itching, and epiphora in the affected eye. Subsequent examination revealed conjunctival congestion and a moving whitish linear formation, which was diagnosed as subconjunctival ocular parasitosis. The patient underwent successful surgical removal of the parasite and recovered without complications. The report highlights the importance of early diagnosis and prompt treatment to prevent permanent vision loss in cases of ocular parasitosis.

Keywords: Ocular parasitosis; Taenia solium; Cysticercosis; Subconjunctival

Introduction

Ocular parasitosis has been a source of interest for ophthalmologists due to the diverse ways it manifests [1]. While ocular involvement is not crucial to the parasite's life cycle, the discovery of intraocular parasites is uncommon and is typically caused by abnormal parasite tissue migration. Ocular pathology can result from either direct invasion and tissue migration of parasite larvae or adults or indirectly from toxic and/or immune-mediated reactions [2].

Cysticercosis is a parasitic infection caused by the cystic form of taenia solium or taenia saginata larvae in human tissue [3]. It spreads through the fecal-oral route, often through contaminated water or food [4]. While adult worms primarily cause intestinal obstruction and malnutrition, larvae can produce more serious conditions, including subcutaneous tissue, muscle, and central nervous system invasion [3]. Ocular structures are affected in 13-46% of infected individuals, and ocular manifestations can be severe, resulting in blindness lasting 3-5 years due to the release of toxic products from the growing or dying cysticercosis [5].

Case Report

This report details an incredibly rare case of a Taenia solium worm discovered under the conjunctiva in a 25-year-old man living in a rural area. The patient presented to the ophthalmology emergency room with redness and pain in the left eye for 7 days, along with itching and epiphora. The episode was not linked to decreased visual acuity, and the patient had no history of ocular trauma, prior similar occurrences, or use of topical medications. The rest of the patient's medical history was unremarkable. Uncorrected visual acuity was 0.1 LogMAR in both eyes, and intraocular pressure was normal. Examination of the left eye revealed conjunctival congestion and a moving whitish linear formation in the nasal region below the bulbar conjunctiva (Figure 1), while the examination of the right eye was normal. The diagnosis was subconjunctival ocular parasitosis, and further tests, including cardiac ultrasound, abdominal ultrasound, and chest X-ray, produced normal results. Routine blood counts were unremarkable, and Enzyme-Linked Immunosorbent Assay (ELISA) for the detection of antibody to cysticerci was negative. Stool examination, on the other hand, revealed Taenia solium ova. Magnetic resonance imaging of the brain and orbit showed cysticercus cyst in the left eye. Surgical extraction of the parasite resulted in the removal of a white, translucent parasite measuring approximately 15mm in length and 0.6mm in diameter. After undergoing surgery to remove the worm and parasitological examination, the patient was treated with anthelmintic medication. The surgical and post-surgical course was favorable.

    

    

    Figure 1: Clinical picture of the affected eye. Note the conjunctival congestion and the whitish linear formation in the nasal region below the bulbar conjunctiva.