Aims To investigate longitudinal choroid and ganglion cell–inner plexiform layer (GCIPL) changes in type 2 diabetes mellitus (T2DM) patients and healthy populations across 2 years.
Methods This prospective cohort study included T2DM patients and healthy controls. T2DM patients were divided into mild non-proliferative diabetic retinopathy (NPDR) or non-DR (NDR) groups. Macular choroidal and GCIPL thickness was measured using swept-source optical coherence tomography at baseline and follow-up after 2 years. A linear-mixed effect model compared rates of change in choroidal and GCIPL thicknesses between the three groups.
Results 895 T2DM patients (770 in the NDR group and 125 in the NPDR group) and 847 healthy controls were included. Following 2 years, choroidal thinning occurred at a rate of −7.7±9.2 µm/year, −8.1±8.7 µm/year and −5.2±8.1 µm/year in NDR, NPDR and control groups, respectively (p<0.001). GCIPL loss occurred quickest in NPDR patients (−0.97±0.97 µm/year), followed by NDR (−0.91±0.89 µm/year) and the control group (−0.04±0.55 µm/year) (p<0.001). Following multivariate adjustment, choroidal thinning was −2.04 µm/year (95% CI: −4.05 to –0.03; p=0.047) and −1.95 µm/year (95% CI: −3.14 to –0.75; p=0.001) faster in NPDR and NDR groups than in the control group, respectively, and GCIPL thinning was −1.02 µm/year (95% CI: −1.19 to –0.84; p<0.001) and −0.88 µm/year (95% CI: −0.98 to –0.78; p<0.001) faster in the NPDR and NDR groups than in the control group, respectively.
Conclusion Progressive choroidal and GCIPL thinning occurs in healthy individuals and T2DM patients; however, T2DM undergoes accelerated choroidal and GCIPL loss in NPDR patients.
Data availability statement
All data relevant to the study are included in the article or uploaded as online supplemental information.
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ZH and XG are joint first authors.
ZZ and WW contributed equally.
Contributors WW and WH had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: WW, YL, XG, ZZ and WH. Acquisition, analysis or interpretation of data: all authors. Drafting of the manuscript: all authors. Critical revision of the manuscript for important intellectual content: all authors. Statistical analysis: WW. Obtained funding: WH and WW. Administrative, technical or material support: ZZ, WH and WW. Study supervision: WH. WH is guarantor.
Funding This study was supported by Guangzhou Science & Technology Plan of Guangdong Pearl River Talents Program (202102010162) and the National Natural Science Foundation of China (82000901) and the Fundamental Research Funds of the State Key Laboratory of Ophthalmology (303060202400362).
Disclaimer The funding organisations had no role in the design or conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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