The reliability of anterior segment lesions as indicators of onchocercal eye disease in Guatemala.


World Health Organization certification criteria for onchocerciasis elimination use anterior segment eye lesion prevalence as an indicator of mass ivermectin treatment program success. Lesions either contain visible microfilaria (noninflammatory punctate keratitis [PK] or microfilariae in anterior chamber [MFAC]), or microfilaria obscured by inflammation (inflammatory PK). To assess the utility of these disease indicators, two experienced ophthalmologists independently examined persons from endemic (N = 325) and nonendemic (N = 348) Guatemalan communities. Thirty-six (11.1%) and nine (2.6%) persons from endemic and nonendemic areas respectively had lesions found by either ophthalmologist (prevalence ratio = 4.3, 95% CI 2.1-8.8, P < 0.001). All lesions in nonendemic areas were inflammatory PK in whom no persons were seropositive for onchocerciasis. Overall, observer agreement was moderate (Kappa = 0.49), and most (61%) discordance occurred with inflammatory PK lesions. Our findings suggest that inflammatory punctate keratitis is neither a specific nor a reliable indicator of onchocercal eye disease. Future prevalence surveys should rely upon noninflammatory lesions as disease indicators.

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@article{Winthrop2006TheRO, title={The reliability of anterior segment lesions as indicators of onchocercal eye disease in Guatemala.}, author={Kevin L Winthrop and Roberto Proa{\~n}o and Orlando Oliva and Byron Arana and Carlos Mendoza and Alfredo Dominguez and Josef Amann and George Punkosdy and Carlos Blanco and Robert Klein and Mauricio Sauerbrey and Frank Richards}, journal={The American journal of tropical medicine and hygiene}, year={2006}, volume={75 6}, pages={1058-62} }