Longitudinal Changes of Parafoveal Vessel Density in Diabetic Patients without Clinical Retinopathy Using Optical Coherence Tomography Angiography

Abstract

Purpose

The purpose of this study was to identify the rate of parafoveal vessel density (VD) changes associated with the progression from non-diabetic retinopathy (NDR) to early stages of DR over a year.

Methods

This longitudinal cohort study enrolled diabetic patients from the Guangzhou community in China. The patients with NDR at baseline were included and underwent comprehensive examinations at baseline and after 1 year. A commercial OCTA device (Triton Plus, Topcon, Tokyo, Japan) was employed to quantify the parafoveal VD in the superficial and deep capillary plexuses. The rates of change in parafoveal VD over time in the incident DR and NDR groups were compared after a year.

Results

A total of 448 NDR patients were included in the study. Among them, 382 (83.2%) were stable and 66 (14.4%) developed incident DR during the 1-year follow-up. The average parafoveal VD in the superficial capillary plexus (SCP) reduced significantly more quickly in the incident DR group than in the NDR group (-1.95 ± 0.45%/year vs. −0.45 ± 0.19/year, p = 0.002). The VD reduction rate for the deep capillary plexus (DCP) was not significantly different for the groups (p = 0.156).

Conclusions

The incident DR group experienced a significantly faster reduction in parafoveal VD in the SCP compared with the stable group. Our findings further provide supporting evidence that parafoveal VD in the SCP may be used as an early indicator of the pre-clinical stages of DR.

Keywords:

• Diabetic retinopathy
• non-diabetic retinopathy
• vessel density changes
• OCTA
• longitudinal study

Acknowledgments

We would like to thank Editage (www.editage.com) for English language editing.

Ethical approval

This study is approved by the Institutional Review Board Ethics Committee of the Zhongshan Ophthalmic Center (2017KYPJ094).

Disclosure statement

No potential conflict of interest was reported by the author(s). The authors have no proprietary or commercial interest in any materials discussed in this article. The study has not been published elsewhere and it has not been submitted simultaneously for publication elsewhere.

Data availability statement

The data that support the findings of this study are available from the corresponding author, WH or CZ, upon reasonable request.

Additional information

Funding

This study was supported by the National Natural Science Foundation of China [Grant 82171084; 81970808], Guangdong Natural Science Foundation [Grant 2020A1515010121].