Ocular anomalies not caused by <i>Onchocerca volvulus</i> infection in patients (n = 82) examined before ivermectin treatment, and at 4 and 23 years post initial ivermectin treatment (PIT).

<p>Ocular anomalies not caused by <i>Onchocerca volvulus</i> infection in patients (n = 82) examined before ivermectin treatment, and at 4 and 23 years post initial ivermectin treatment (PIT).</p

Iridocyclitis, cataract, papillitis and chorioretinitis in onchocerciasis patients (n = 82) post ivermectin treatment. Differences were evaluated using Pearson's chi-square test.

$<p>PIT =  post initial treatment.</p><p>PES =  Posterior Eye Segment.</p>$$<p>Other Lesions: Phtyse, Pupille scleroatrophic, Synechie post trauma, Pigments on posterior Capsule.</p>§§<p>Other Lesions: Phtyse, dead O.volvulus microfilariae on posterior capsule.</p>&&<p>Other Lesions: optic cup/disc >0.5.</p>§§§<p>Other Lesions  =  retina detachment from the retinal pigment epithelium, drusen.</p><p>*p<0.001 compared to 4 years PIT;</p><p>**p<0.001 compared to before ivermectin;</p><p>***p<0.0001 compared to before ivermectin and 4 years PIT.</p>&<p>p<0.01 compared to before ivermectin.</p

Sustainable Control of Onchocerciasis: Ocular Pathology in Onchocerciasis Patients Treated Annually with Ivermectin for 23 Years: A Cohort Study

<div><p>The evolution and persistence of ocular pathology was assessed in a cohort of <i>Onchocerca volvulus</i> infected patients treated annually with ivermectin for 23 years. Patients were resident in rural Central and Kara Region of Togo and ocular examinations included testing of visual acuity, slit lamp examination of the anterior eye segment and the eye fundus by ophthalmoscopy. Before ivermectin treatment, vivid <i>O.volvulus</i> microfilariae (MF) were observed in the right and left anterior eye chamber in 52% and 42% of patients (n = 82), and dead MF were seen in the right and left cornea in 24% and 15% of cases, respectively. At 23 years post initial treatment (PIT), none of the patients (n = 82) presented with MF in the anterior chamber and cornea. A complete resolution of punctate keratitis (PK) lesions without observable corneal scars was present at 23 years PIT (p<0.0001), and sclerosing keratitits (SK) lessened by half, but mainly in patients with lesions at early stage of evolution. Early-stage iridocyclitis diminished from 42%(rE) and 40%(lE) to 13% (rE+lE)(p<0.0001), but advanced iridocyclitis augmented (p<0.001) at 23 years PIT compared to before ivermectin. Advanced-stage papillitis and chorioretinitis did not regress, while early-stage papillitis present in 28%(rE) and 27%(lE) of patients at before ivermectin regressed to 17%(rE) and 18%(lE), and early-stage chorioretinitis present in 51%(rE+lE) of cases at before ivermectin was observed in 12%(rE) and 13%(lE) at 23 years PIT (p<0.0001). Thus, regular annual ivermectin treatment eliminated and prevented the migration of <i>O. volvulus</i> microfilariae into the anterior eye chamber and cornea; keratitis punctata lesions resolved completely and early-stage sclerosing keratitits and iridocyclitis regressed, whilst advanced lesions of the anterior and posterior eye segment remained progressive. In conclusion, annual ivermectin treatments may prevent the emergence of ocular pathology in those populations still exposed to <i>O.volvulus</i> infection.</p><p><i>Trial Registration</i>: <a href="http://www.pactr.org" target="_blank">www.pactr.org</a><a href="http://www.pactr.org/ATMWeb/appmanager/atm/atmregistry?dar=true&tNo=PACTR201303000464219" target="_blank">PACTR201303000464219</a>)</p></div

Causes of bilateral visual impairment and blindness in the onchocerciasis patients' cohort (n = 82) before ivermectin treatment, and at 4 years and 23 years post initial treatment (PIT).

<p>The patients' visual acuity was graded according to WHO criteria; blind were those with a visual acuity on the right (RE) or left eye (LE) or both eyes (RLE) of less than 1/20 (3/60 or unable to count fingers at 3 meters); impaired vision had those with a visual acuity between 1/20 (3/60) and less than 3/10 (6/18); good vision had those with a visual acuity equal or greater than 3/10.</p

Microfilaria in the anterior chamber of the eye, the cornea, and puctate and sclerosing keratitis in onchocerciasis patients (n = 82) post ivermectin treatment. Differences were evaluated using Pearson's chi-square test.

$<p>PIT =  post initial treatment.</p><p>*p<0.001 compared to 4 years PIT;</p><p>**p<0.001 compared to before ivermectin;</p><p>***p<0.0001 compared to before ivermectin and 4 years PIT.</p