Investigation of Choroidal Blood Flow and Thickness Changes Induced by Near Work in Young Adults

Abstract

Purpose

This research aimed to determine the effects of near work on macular choroidal blood flow and thickness in young adults.

Methods

A total of 109 participants (19–28 years old) were recruited from Capital Medical University in China. The participants spent 40 min reading a book text at a distance of 33 cm. Swept-source optical coherence tomography/optical coherence tomography angiography (SS-OCT/OCTA) was performed to measure the changes in choriocapillaris perfusion area (CCPA) and choroidal thickness (ChT) after 40 min of near work. The SS-OCT/OCTA data covered an area of 6 mm × 6 mm, which centered on the fovea.

Results

The baseline ChT and CCPA before near work were negatively correlated with AL, while positively correlated with the magnitude of spherical equivalent (p < .001). Total CCPA decreased significantly by 6 mm × 6 mm macular area after near work compared to that before near work (24.26 ± 1.96 vs. 24.63 ± 1.61 mm², p<.001). The macular ChT was lower after 40 min of reading than that before 40 min of reading, but no significant difference was observed (302.25 ± 77.69 vs. 304.92 ± 79.73 μm, p = .078). The extent of choroidal thinning was significantly positively correlated with the magnitude of CCPA reduction (p < .001). The decline in CCPA after near work was significantly positively correlated with axial length (AL; p < .001).

Conclusion

This study demonstrated that near work significantly decreased CCPA. The extent of CCPA reduction after near work was associated with higher severity of myopia and choroidal thinning. The baseline CCPA and ChT decreased gradually with AL.

Keywords:

• Choriocapillaris perfusion area
• choroidal thickness
• near work
• optical coherence tomography angiography
• myopia

Acknowledgements

The authors thank all staffs who contributed to this study.

Authors’ contributions

All authors contributed to the study conception and design; data collection: Xintong Liang, Shifei Wei, Shengjun Zhao, Wenzai An, Weiling Bai, Yunyun Sun, Zhining Cai; statistical expertise: Xintong Liang, Shengjun Zhao; administrative, technical and logistic support: Shi-Ming Li, Ningli Wang; analysis and interpretation: Xintong Liang; writing the article: Xintong Liang; critical revision of the article: Xintong Liang, Shifei Wei, Ningli Wang, Shi-Ming Li; final approval of the article: Xintong Liang, Shifei Wei, Shengjun Zhao, Shi-Ming Li, Wenzai An, Yunyun Sun, Weiling Bai, Zhining Cai, Ningli Wang. All authors reviewed the manuscript and agreed to be accountable for all aspects of the work.

Ethical approval

This clinical study was conducted in accordance with the ethical principles contained within Declaration of Helsinki.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by grants from the Beijing Municipal Administration of Hospitals Incubating Program (PX2022007), the primary scientific research foundation for the junior researcher in Beijing Tongren Hospital, Capital Medical University (2020-YJJ-ZZL-011), the capital health research and development of special (2020-2-1081), the National Natural Science Foundation of China (82071000), and the Beijing Science Foundation for Distinguished Young Scholars (JQ20029).