The geospatial relationship of pterygium and senile cataract with ambient solar ultraviolet in tropical Ecuador.

Tropical Ecuador presents a unique climate in which we study the relationship between the ambient levels of solar ultraviolet radiation and eye disease in the absence of a latitudinal gradient. The national distribution of surface ultraviolet, taking into account MODIS and OMI satellite observation of aerosol, ozone, surface albedo, local elevation and cloud fractions measured during 2011, was compared with the national pterygium (WHO ICD H11) and senile cataract (WHO ICD H25) incidence projected from the 2010 National Institute of Statistics and Census (Ecuador). Public Health Ministry projections for age categories 0 to 39, 40 to 59 and 60+ years were compared to surface ultraviolet irradiance data in 1040 parishes.