Onchocerciasis, also known as river blindness, is caused by the parasitic worm Onchocerca volvulus transmitted through repeated bites from infected blackflies. It is the world's second leading infectious cause of blindness. Symptoms include intense itching, skin swelling, and vision loss. Left untreated, the infection can lead to corneal opacification, glaucoma, cataracts and ultimately blindness. Treatment involves doses of ivermectin along with antibiotics to kill the Wolbachia bacteria in the adult worms. Early treatment may prevent permanent vision loss but outcomes depend on the disease stage at presentation.

1. Onchocerciasis
Presented By- Pradumn Vishwakarma
3rd Year
CLGSO

2. Introduction
• Onchocerciasis also known as “river blindness” and Robles disease.
• It is caused by the parasitic worm Onchocerca volvulus, a nematoda.
• It is world’s 2nd leading infectious cause of blindness.

3. • It is transmitted to humans through exposure to repeated bites of
infected blackflies of the genus Simulium.
• 14.6 million of the infected people already had skin disease and 1.15
million had vision loss.
• 99% of infected people live in 31 African countries.

4. Life Cycle

5. Sign & Symptoms
• Intense itching, swelling and inflammation, loss of elasticity,
depigmentation.
• Ocular complain are of an insidious onset of decreased vision, eye
redness, eye pain and photophobia related to iridocyclitis, and
perceived corneal changes related to the sclerosing keratitis.

6. Chronic lichenification with papular dermatitis (left); Sclerosing keratitis (right)

7. Ocular Menifestation
• The infection can lead to corneal opacification (sclerosing keratitis),
secondary angle closure and open angle glaucoma, cataracts,
chorioretinitis, and optic atrophy.
• Combined, these manifestations lead to the blindness that gives the
disease its name.

9. Treatment
• Two doses of ‘ivermectin’ because it only needs to be taken once or
twice a year.
• Antibiotics
• Doxycycline is used to kill the Wolbachia bacteria that live in adult worm

10. Prognosis
• Depends on the stage at which the infection is treated , if treated early
the corneal opacities may be minimal and may recede with appropriate
treatment.
• As the disease progresses, the visual outcomes can progress towards
blindness and may be irreversible.