PURPOSE

To determine the independent, relative, and combined impact of reduced distance and near vision on the vision-specific quality of life (VS QOL) of adults in Timor-Leste.

DESIGN

A population-based cross-sectional eye health survey was conducted in urban and rural areas in Timor-Leste.

PARTICIPANTS

Participants were 40 years or older. Those with better eye presenting distance vision worse than 6/18, and every third participant with 6/18 or better vision, completed the VS QOL questionnaire: in total 704 of the 1414 participants.

METHODS

Distance and near visual acuities were measured and eye health was assessed. The VS QOL questionnaire administered by interview was analyzed using Rasch analysis, univariate analysis, and linear regression to determine associations between VS QOL, demographic factors, and levels of visual impairment.

MAIN OUTCOME MEASURES

The Timor-Leste VS QOL questionnaire results.

RESULTS

Rasch analysis confirmed that for participants both with and without visual impairment, the Timor-Leste VS QOL questionnaire provided a valid and reliable measure, was unidimensional, and had appropriate response categories. There was a consistent pattern of deterioration in VS QOL as vision worsened: for each category of distance- and near-vision impairment, there was an independent and significant change in Timor-Leste VS QOL scores between no visual impairment and either mild, moderate, or severe impairment (P < 0.05). Combined distance- and near-vision impairment was associated with a greater impact on VS QOL than categories separately, the impact of severe distance- and near-vision impairment being the greatest and clinically significant: -3.05 (95% confidence interval [CI], -3.60 to -2.49; P<0.05; and 95% CI, <-1.0). Distance vision (37.2%) contributed relatively more than near vision (4.7%) to the total variance in VS QOL (41.9%). Older people, those not married, not literate, and rural dwellers had significantly worse Timor-Leste VS QOL scores (P < 0.05).

CONCLUSIONS

This study provides evidence of independent dose-response relationships between distance- and near-vision impairment and poorer VS QOL. Distance-vision impairment had a relatively larger impact on VS QOL than near-vision impairment. Combined distance- and near-vision impairment was associated with a greater impact on VS QOL compared with the independent impact of distance- or near-vision impairment at similar levels.