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Abstract #45893 Published in IGR 13-2
Prevalence of chronic ocular diseases in a genetic isolate: The norfolk island eye study (NIES)
Sherwin JC; Kearns LS; Hewitt AW; Ma Y; Kelly J; Griffiths LR; Mackey DAOphthalmic Epidemiology 2011; 18: 61-71
Purpose: Over 40% of the permanent population of Norfolk Island possesses a unique genetic admixture dating to Pitcairn Island in the late 18(th) century, with descendents having varying degrees of combined Polynesian and European ancestry. We conducted a population-based study to determine the prevalence and causes of blindness and low vision on Norfolk Island. Methods: All permanent residents of Norfolk Island aged (greater-than or equal to) 15 years were invited to participate. Participants completed a structured questionnaire/interview and underwent a comprehensive ophthalmic examination including slit-lamp biomicroscopy. Results: We recruited 781 people aged (greater-than or equal to) 15, equal to 62% of the permanent population, 44% of whom could trace their ancestry to Pitcairn Island. No one was bilaterally blind. Prevalence of unilateral blindness (visual acuity [VA] < 6/60) in those aged (greater-than or equal to) 40 was 1.5%. Blindness was more common in females (P=0.049) and less common in people with Pitcairn Island ancestry (P<0.001). The most common causes of unilateral blindness were age-related macular degeneration (AMD), amblyopia, and glaucoma. Five people had low vision (Best-Corrected VA < 6/18 in better eye), with 4 (80%) due to AMD. People with Pitcairn Island ancestry had a lower prevalence of AMD (P<0.001) but a similar prevalence of glaucoma to those without Pitcairn Island ancestry. Conclusions: The prevalence of blindness and visual impairment in this isolated Australian territory is low, especially amongst those with Pitcairn Island ancestry. AMD was the most common cause of unilateral blindness and low vision. The distribution of chronic ocular diseases on Norfolk Island is similar to mainland Australian estimates.
D. A. MacKey. Lions Eye Institute, Centre for Ophthalmology and Visual Science, University of Western Australia, 2 Verdun St., Nedlands, WA 6009, Australia. Email: D.Mackey@utas.edu.au
Classification:
1.1 Epidemiology (Part of: 1 General aspects)
