Purpose To investigate the 5-year changes in static and dynamic anterior segment optical coherence tomography (AS-OCT) parameters and their predictors.
Methods This was a prospective, population-based cohort study of people aged 50 years and older residing in the Liwan District, Guangzhou, China. Standardised AS-OCT scans were performed in November 2008 and November 2013 under dark and light conditions. Customised software was used to analyse horizontal AS-OCT images. Parameters in dark and measurements of light-to-dark changes were used for analyses.
Results A total of 186 (71.8%) subjects underwent AS-OCT twice, 5 years apart and were included for analyses. The mean age in 2008 was 64.7±7.0 years, and 60.2% were women. The anterior chamber width (ACW) decreased from 11.74±0.44 mm in 2008 to 11.60±0.37 mm in 2013 (p=0.001). There was a trend towards a decrease in dynamic capacity (light-to-dark changes) in the anterior segment, with decreased iris thickness at 750 µm (ΔIT750), ΔACW, Δ anterior chamber area (ACA) and Δ pupil diameter at 5 years (all p<0.05). After adjusting for age and sex, the following baseline parameters were associated with a greater decrease rate in trabecular iris space area at 500 µm (TISA500) at 5 years: TISA500, IT750 and ACA in dark (p<0.001 for all).
Conclusions Anterior chamber angle width decreased and the amount of light-to-dark changes declined during 5-year follow-up. Subjects with greater height, wider angle width and thicker iris at baseline have greater angle narrowing at follow-up.
- population-based study
- anterior segment optic coherence tomography
- angle closure
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YJ, DW, WW and FC are joint first authors.
Contributors Conception and design MH; data collection YJ, WW, FC, WH; SH; analysis and interpretation YJ, DW, FC, WW, WH, SH, MH; writing of the article YJ, DW, WW, FC, JS; critical revision of the article: MH.
Funding This research was supported in part by the grant from the Fundamental Research Funds of the State Key Laboratory in Ophthalmology (81420108008 81570843 H1204), Science and Technology Planning Project of Guangdong Province, China (2013B20400003). MH receives support from the University of Melbourne at Research Accelerator Program and the CERA Foundation. The Centre for Eye Research Australia receives Operational Infrastructure Support from the Victorian State Government. No additional external funding was received.
Competing interests None declared.
Patient consent for publication Not required.
Ethics approval Ethical approval was obtained from the zhongshan Ophthalmic Center Ethics Review Board and the Research Governance Committee of Moorfields Eye Hospital in London, England. ID:  No.12.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement Data are available upon request.
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