Survey of ophthalmic conditions in a Labrador community: II. Ocular disease.

An ophthalmic examination of 87% of the resident population of Nain, Labrador (latitude 56 degrees 33'N) was carried out, and the findings in 330 Inuit, 236 persons of mixed racial ancestry (Inuit-Caucasian) and 80 Caucasians were analysed. Legal blindness was present in 1.2% of the survey population, compared with 1.6% of the study population of the Arctic Ophthalmological Survey of 1970-71. Of the age group 52 to 85 years, 10.8% were legally blind, compared with 0.6% of the same age group surveyed in the Framingham (Massachusetts) Eye Study. The leading causes of unilateral or bilateral blindness in Nain were trauma, especially in the Inuit, and spheroidal degeneration (Labrador keratopathy); neither senile macular degeneration nor diabetic retinopathy had caused legal blindness. External diseases, particularly spheroidal degeneration (which affected 19% of the population), phlyctenular keratoconjunctivitis and epiblepharon, were the commonest diagnoses in Nain. No diabetic retinopathy was detected, but evidence of toxoplasmosis was encountered. Compared with the study population of the Arctic Ophthalmological Survey, the Nain population had a higher prevalence of spheroidal degeneration and other corneal diseases.