Table 3.

Ocular parasitosis caused by round worms (geographical distribution & ocular findings).

Disease/Infection	Causative agent	Geographical distribution	Ocular findings
Angiostrongyliasis	Angiostrongylus cantonensis	Southeast Asia, Pacific region, eastern Australia	Blurred vision and poor visual acuity
Bancroftian and Brugian filariasis	W. bancrofti, B. malayi	Southeast Asia	Retinal vasculities, decreased vision and panuveitis with secondary glaucoma
Baylisascariasis	Baylisascaris procyonis	Few records in US, Japan, Germany	Vision loss, transient visual obscuration, and diffuse unilateral subacute neuroretinitis
Dirofilariasis	Dirofilaria repens	Europe, Asia and Africa	Pain, oedema, and congestion of the conjunctiva, diplopia, foreign body sensation in the eye
Loiasis	Loa loa	Central and West Africa	Conjunctival congestion and pain with movement of the eye. May affect vision transiently. Retinal hemorrhages and perivascular inflammation
Onchocerciasis	Onchocerca volvulus	Tropical Africa, South America, and the Arabian peninsula	Chorioretinitis, keratitis, uveitis, corneal opacification, neovascularisation, blindness
Thelaziasis	Thelazia callipaeda	Asian Pacific region	Epiphora, conjunctivitis, keratitis, corneal opacity and ulcers
Toxocariasis	Toxocara canis and Toxocara cati	Wide spread	Peripheral white mass is often visible in affected eyes
Trichinosis	Trichinella spiralis	Central and eastern Europe, united States	Oedema around the eye, conjunctivitis and exophthalmoses