Five-year visual outcome among people with correctable visual impairment: the Liwan Eye Study

Importance: Longitudinal data on visual outcome of correctable visual impairments (VI) are of paramount importance for decision-maker to estimate burden and demand to treat avoidable VI.

Background: To assess the 5-year visual outcome among participants with correctable VI and to identify associated risk factors.

Design: Population-based longitudinal cohort study.

Participants: Participants with correctable VI at baseline attended the 5-year follow-up visit of the Liwan Eye Study.

Methods: Presenting visual acuity (PVA) with habitual refractive correction was assessed using an Early Treatment Diabetic Retinopathy Study (ETDRS) chart. Then participants with PVA <6/12 in either eye underwent further non-cycloplegic subjective refraction to obtain their best-corrected visual acuity. Correctable VI was defined as having a PVA of <6/12 in the better eye which could be improved to ≥6/12 after refractive correction.

Main outcome measures: The 5-year visual outcome among participants with correctable VI.

Results: Among 1405 participants at baseline examination, 188 (13.4%) had correctable VI, of whom 118 (62.8%) were re-examined at the 5-year follow-up, including 39 (33.9%) who progressed to non-correctable VI, 43 (37.4%) who had persistent correctable VI and 33 (28.7%) who were converted to normal vision. In multivariate logistic regression, compared with participants who were no longer visual impaired, significant risk factors for participants with persistent VI were older, had income <1000 RMB/month, and more myopia spherical equivalent.

Conclusions and relevance: Over two of three participants with correctable VI remained to have VI after 5 years, among whom 50% are correctable by spectacles, highlighting the need to improve the refractive care accessibility to treat avoidable VI in China.