Blindness and vision impairment in the elderly of Papua New Guinea

To estimate the magnitude and causes of blindness and vision impairment in Papua New Guinea for service delivery planning and ophthalmic education development.

Using the World Health Organization standardized Rapid Assessment of Cataract Surgical Services protocol, a population-based cross-sectional survey was conducted in 2005. By systematic, two-stage cluster random sampling, 39 clusters each of 30 people aged 50 years and over were selected from urban and rural locations. A cause of vision loss was determined for each eye with a presenting visual acuity worse than 6/18.

Of the 1191 people enumerated, 1174 were examined (98.6%). The 50 years and older age-gender adjusted prevalence of vision impairment (presenting visual acuity less than 6/18 in the better eye) was 29.2% (95% Confidence Interval [CI]: 27.6, 35.1, Design Effect [deff] = 2.3). That of functional blindness (presenting visual acuity less than 6/60 in the better eye) was 8.9% (95% CI: 8.4, 12.0, deff = 1.2), and of World Health Organization blindness (but presenting, rather than best corrected, visual acuity of less than 3/60 in the better eye) was 3.9% (95% CI: 3.4, 6.1, deff = 1.0). Uncorrected refractive error (13.1%, 95% CI: 11.3, 15.1, deff = 1.2) and cataract (7.4%, 95% CI: 6.4, 10.2, deff = 1.3) were leading causes of vision impairment, age-gender adjusted. Cataract was the most common (age-gender adjusted 6.4%, 95% CI: 5.1, 7.3, deff = 1.1) cause of functional blindness. On bivariate analysis, increasing age (P < 0.001), illiteracy (P < 0.001) and unemployment (P < 0.001) were associated with functional blindness. Gender was not.

The identification and treatment of refractive error and cataract need to be priorities for eye health services in Papua New Guinea if the burden of vision impairment and blindness is to be diminished. The education of community and hospital eye care providers, whether medical, nursing or other cadres, must emphasize these. Eye care services must be structured and provided to allow and encourage accessibility and uptake, with satisfactory treatment outcomes for these conditions.