Update on pathology of ocular parasitic disease.

Parasites are a group of eukaryotic organisms that may be free‑living or form a symbiotic or parasitic relationship with the hosts. Consisting of over 800,000 recognized species, parasites may be unicellular (Protozoa) or multicellular (helminths and arthropods). The association of parasites with human population started long before the emergence of civilization. Parasitic zoonotic diseases are prevalent worldwide including India. Appropriate epidemiological data are lacking on existing zoonotic parasitic diseases, and newer diseases are emerging in our scenario. Systemic diseases such as cysticercosis, paragonimiasis, hydatidosis, and toxoplasmosis are fairly common. Acquired Toxoplasma infections are rising in immune‑deficient individuals. Amongst the ocular parasitic diseases, various protozoas such as Cystoidea, trematodes, tissue flagellates, sporozoas etc. affect humans in general and eyes in particular, in different parts of the world. These zoonoses seem to be a real health related problem globally. Recent intensification of research throughout the world has led to specialization in biological fields, creating a conducive situation for researchers interested in this subject. The basics of parasitology lie in morphology, pathology, and with recent updates in molecular parasitology, the scope has extended further. The current review is to address the recent update in ophthalmic parasites with special reference to pathology and give a glimpse of further research in this field.

A Case of Recurrent External Ophthalmomyiasis Caused by Lucilia sericata Meigen in a Healthy Patient

PURPOSE: To report a case of recurrent external ophthalmomyiasis caused by Lucilia sericata Meigen in a healthy patient. CASE SUMMARY: A 72-year-old male, who was diagnosed 7 months earlier with ophthalmomyiasis and obtained permanent relief by surgical treatment, presented with severe tearing, redness, foreign body sensation, pain in both eyes and aural discomfort in the left ear. On presentation, visual acuity in both eyes was hand movement. On slit lamp examination, total corneal epithelial defect with stromal infiltrations was observed. However, there were no motile organisms in his eyes due to previous removal of maggots at a local clinic. On physical examination, eschar change was observed at the inferomedial area of the left lower eyelid. On otorhinolaryngological examination, several motile organisms with tympanic membrane perforation were observed in the left external acoustic meatus. The patient was treated with topical antibiotic eye drops hourly with systemic antibiotics, and 6 larvae were removed from the external acoustic meatus using otoscopy. Microscopic findings of the removed larvae revealed L. sericata in their third stage of development. After 1 month, corneal epithelial defect and stromal infiltration improved. However, visual acuity in both eyes was 0.1 due to remaining stromal opacities. CONCLUSIONS: In a healthy patient without any predisposing factors, recurrent ophthalmomyiasis accompanied with aural myiasis can develop under poor hygiene conditions.

Human ophthalmomyiasis externa caused by the sheep botfly Oestrus ovis：a case report from Karachi, Pakistan

Ocular myiasis due to Oestrus ovis larvae infestation is an eye infection in humans. A case of ophthalmomyiasis externa in a young male from Karachi, Pakistan in winter (December 2012), without history of close proximity to domestic animals or visit to any rural area was reported. The condition is self-limiting and the disease is confined to the conjunctiva. The eye was locally anesthetized and washed with 5% povidine iodine solution. A total number of 27 first instar larvae of Oestrus ovis were removed with fine forceps. The patient received 0.5% moxifloxacin and diclofenac eye drops for one week. His eye was examined after one day, one week and one month and the recovery status was favorable. The present case raise the awareness among ophthalmologists regarding larval conjunctivitis as one of the causes of conjunctivitis and it can occur throughout the year in any season including winter. Moreover, it can occurr in any area either rural or urban with or without close proximity to domestic animals especially in subtropical regions with high parasitic burden.

Human ophthalmomyiasis externa caused by the sheep botfly Oestrus ovis: A case report from Karachi, Pakistan

Ocular myiasis due to Oestrus ovis larvae infestation is an eye infection in humans. A case of ophthalmomyiasis externa in a young male from Karachi, Pakistan in winter (December 2012), without history of close proximity to domestic animals or visit to any rural area was reported. The condition is self-limiting and the disease is confined to the conjunctiva. The eye was locally anesthetized and washed with 5% povidine iodine solution. A total number of 27 first instar larvae of Oestrus ovis were removed with fine forceps. The patient received 0.5% moxifloxacin and diclofenac eye drops for one week. His eye was examined after one day, one week and one month and the recovery status was favorable. The present case raise the awareness among ophthalmologists regarding larval conjunctivitis as one of the causes of conjunctivitis and it can occur throughout the year in any season including winter. Moreover, it can occurr in any area either rural or urban with or without close proximity to domestic animals especially in subtropical regions with high parasitic burden.

Ophthalmomyiasis externa by Musca domestica in a case of orbital metastasis.

bone destruction with extension into surrounding sinuses. Over 200 maggots were manually removed after immobilisation with turpentine oil instillation. Entomological examination showed it to be a case of accidental myiasis caused by the common housefly Musca domestica. The patient was managed conservatively and the ulcer cavities filled up with healthy granulation tissue. This case is presented on account of its rarity.

Red eye: Rule out Ophthalmomyiasis too.

Ophthalmomyiasis is the infestation of human eye by the larvae of certain flies. Sheep botfly commonly manifests as Ophthalmomyiasis externa when there is conjunctival involvement or rarely as Opthalmomyiasis interna when there is larval penetration into the eyeball. It appears to be more common than what has been indicated by previously published reports. We present a report of seven cases of Ophthalmomyiasis by Oestrus ovis, from central India who presented with features of conjunctivitis varying between mild to severe. The larvae were seen in bulbar and palpebral conjunctiva and also entangled in lashes with discharge. Since the larvae are photophobic, it is prudent to look for them in the fornices and also in discharge. Prompt removal of the larvae from the conjunctiva helps in relieving the symptoms and also prevents serious complications. Taxonomic identification of the species is important to estimate the risk of globe penetration by the larvae.

External Ophthalmomyiasis Presenting to an Emergency Department: Corneal Findings as a Sign of Oestrus ovis

PURPOSE: This study aims to determine the frequency of opthalmyomyiasis externa and the ocular findings of disease in Southern Khorasan. METHODS: All patients referred to the emergency department of Valiaser hospital during the year 2011 with external ophthalmomyiasis were enrolled in this study. The diagnosis of external ophthalmomyiasis was made according to clinical findings and the presence of Oestrus ovis larvae. RESULTS: There were 18 cases of external ophthalmomyiasis in the emergency department of Valiaser hospital in 2011. Most cases had the common signs and symptoms of allergic conjunctivitis, except for three males who were referred with respective complaints of red eye, foreign body sensation, and swelling around the eyelids after contact injury the previous day; corneal infiltration was present in three cases. The visual acuity among the three cases that had peripheral corneal involvement was 20 / 30 in both eyes. The bulbar conjunctiva showed chemosis in all cases and a ropy pattern discharge that was clinically compatible with external ophthalmomyiasis. However, in one case, microscopic slit lamp examination did not show Oestrus ovis larvae. CONCLUSIONS: The frequency of external ophthalmomyiasis was high in this region. Although external ophthalmomyiasis usually manifests as allergic conjunctivitis, coronary-like corneal infiltration may be considered in the differential diagnosis of external ophthalmomyiasis or toxic insult.

Ophthalmomyiasis Caused by a Phormia sp. (Diptera: Calliphoridae) Larva in an Enucleated Patient

Ophthalmomyiasis rarely occurs worldwide, and has not been reported in Korea. We present here a case of ophthalmomyiasis caused by Phormia sp. fly larva in an enucleated eye of a patient. In June 2010, a 50-year-old man was admitted to Dankook University Hospital for surgical excision of a malignant melanoma located in the right auricular area. He had a clinical history of enucleation of his right eye due to squamous cell carcinoma 5 years ago. During hospitalization, foreign body sensation developed in his right eye, and close examination revealed a fly larva inside the eye, which was evacuated. The larva was proved to be Phormia sp. based on the morphology of the posterior spiracle. Subsequently, no larva was found, and the postoperative course was uneventful without any complaints of further myiasis. This is the first case of ophthalmomyiasis among the literature in Korea, and also the first myiasis case caused by Phormia sp. in Korea.

Oestrus ovis ophthalmomyiasis with keratitis.

A 35-year-old male patient presented with complaints of redness, swelling around the eyelids, watering, and irritation in the right eye. At presentation his best-corrected visual acuity was 20/20 partial in the right eye. The tarsal conjunctiva of the upper eyelid showed injection with pseudomembrane. Underneath the pseudomembrane we noticed four motile larvae. The cornea showed an irregular cobweb-like mucous plaque adherent to the epithelium, with a clear stroma. The pseudomembrane was easily peeled-off under topical anaesthesia. The organisms were removed and identified as Oestrus ovis. Three days later the patient was comfortable and his visual acuity was 20/20 in the right eye.

Ophthalmomyiasis: Three cases from North India.

Three cases of external ophthalmomyiasis are reported here. The larvae were identified to be Oestrus ovis in two cases and Cochliomyia hominivorax in one. Two of the patients were immunocompetent while one was undergoing treatment for squamous cell carcinoma of eyelid. In the latter myiasis led to complete destruction of the eye.

External Ophthalmomyiasis Caused by Oestrus ovis: A Rare Case Report from India

Myiasis of different organs has been reported off and on from various regions in the world. We report a human case of external ophthalmomyiasis caused by the larvae of a sheep nasal botfly, Oestrus ovis, for the first time from Meerut city in Western Uttar Pradesh, India. A 25-year-old farmer presented with severe symptoms of conjunctivitis. The larvae, 3 in number, were observed in the bulbar conjunctiva, and following removal the symptoms of eye inflammation improved within a few hours.