|Year : 2018 | Volume
| Issue : 1 | Page : 26-28
Subconjunctival Loa Loa worm: A case report
Nirmal Fredrick, Sunitha Nirmal, SP Sukanya
Nirmal's Eye Hospital, 108, Ayyasamy Street, West Tambaram, Chennai, Tamil Nadu, India
|Date of Web Publication||4-Jun-2018|
Dr. Nirmal Fredrick
108, Ayyasamy Street, West Tambaram, Chennai - 600 045, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Ocular Loiasis although not frequently encountered, is reported from various parts of India. We report one such case of subconjunctival loa loa worm in a patient, who had no history of international travel or immigration. A 62 year old male patient presented with complaints of pain, redness, irritation and watering in the left eye since one day. On examination of the left eye, there was conjunctival congestion and a white thread like mobile worm was noticed in the subconjunctival space nasally. Under aseptic precautions and topical anaesthesia, a single white 5 cm long worm was removed alive and sent for histopathological examination, which reported it as an adult female loa loa worm.
Keywords: Loa loa, Subconjunctival Loa Loa, Loa loa worm
|How to cite this article:|
Fredrick N, Nirmal S, Sukanya S P. Subconjunctival Loa Loa worm: A case report. TNOA J Ophthalmic Sci Res 2018;56:26-8
| Introduction|| |
Loa loa (African eye worm) is a filarial nematode endemic in the rainforest belt of Western and Central Africa. The main clinical manifestation is the presence of adult worms in the eye (subconjunctival or anterior chamber) or Calabar swellings.
| Case Report|| |
A 62-year-old male patient presented to our outpatient department with complaints of pain, redness, irritation, and watering in the left eye for the past 1 day. On examination of the left eye, there was conjunctival congestion and a white thread-like mobile worm was noticed in the subconjunctival space nasally [Figure 1]a and [Figure 1]b. Anterior segment showed no signs of inflammation and the posterior segment was normal. Rest of the ocular examination was unremarkable in both the eyes. The best-corrected visual acuity was 6/6 N6 in both the eyes. The intraocular pressure was within normal limits. The patient was a type 2 diabetic with good metabolic control. Blood investigations such as complete hemogram and random blood sugar were performed which were within normal limits. B-scan ultrasound was carried out which ruled out the presence of additional worms in either eyes [Figure 2].
|Figure 1: (a and b) On clinical examination, a white thread-like mobile worm was noticed subconjunctivally|
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The patient was planned for the removal of worm under local anesthesia. Under aseptic precautions and topical anesthesia, a 3-mm incision was made in the nasal conjunctiva. A single white, 5-cm long worm was removed alive using plain conjunctival forceps [Figure 3]a,[Figure 3]b,[Figure 3]c and measured approximately 2 inch in length [Figure 4]. It was sent for histopathological examination.
|Figure 4: A thin white thread-like worm measuring 5 cm following extraction|
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The patient was started on oral prednisolone 1 mg/kg, antibiotic and steroid combination eye drops and lubricating drops. The histopathological examination reported it as an adult female Loa loa worm, after which the patient was started on oral albendazole 400 mg and diethylcarbamazine (DEC) 300 mg. On subsequent follow-ups, the patient was asymptomatic and the wound was healed well.
| Discussion|| |
Loiasis is a parasitic infection caused by the nematode Loa loa belonging to the family Filarioidea. It is endemic in the rainforest belt of Western and Central Africa. Human infestation occurs through the bites of deerflies of the genus Chrysops. Humans are the only known reservoirs. Multiple larvae are injected into the bloodstream through the bite of deerfly, which then grow into adult worms and migrate to the lymphatics and subcutaneous tissues. The adult female worm sheds microfilariae into the blood which can be detected by a peripheral smear.
Clinical manifestations are caused by the subcutaneous migration of the adult worm. It can occur as multiple subcutaneous, nonpitting, and nontender edema, which is frequently localized to the extremities, known as Calabar swellings. Migration of the worm to the eye can occur subconjunctivally or to the anterior chamber.
Clinical diagnosis is made by the history and the presence of adult worm subconjunctivally or in the anterior chamber. Other investigations such as blood peripheral smear for microfilariae and eosinophil count can be supportive of diagnosis.
Subconjunctival Loa loa is reported from various parts of India  and around the world. Ocular manifestation commonly involves the spread of the worm to the subconjunctival space, but it is also reported to infest the eyelids and the anterior chamber., Most of the case reports and series available report the removal of the worm alive; however, in some cases, the worm is dead before removal. Treatment comprises removal of the worm followed by treating the disseminated microfilaremia. DEC and ivermectin have been shown to be highly effective single agents in reducing the levels of microfilariae in the blood, thereby preventing their uptake and transmission by mosquitoes. Although albendazole reduces the microfilariae load slowly as compared to DEC and ivermectin, it is associated with lesser incidence of encephalopathy.
Following systemic therapy, immunocompromised patients or patients with high microfilarial load may experience a severe inflammatory reaction due to the dying microfilariae, which can even lead to encephalopathy. Therefore, treatment is given under cover of steroids.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]