Effects of accommodation on geometrical parameters of human lens: A systematic review and meta-analysis

Guanghong Zhang; Jun Jiang; Qian Wei; Chao Qu

doi:10.1016/j.heliyon.2024.e29298

Effects of accommodation on geometrical parameters of human lens: A systematic review and meta-analysis

Heliyon. 2024 Apr 16;10(8):e29298. doi: 10.1016/j.heliyon.2024.e29298. eCollection 2024 Apr 30.

Authors

Guanghong Zhang^{1

2

3}, Jun Jiang^{1

2

3}, Qian Wei⁴, Chao Qu^{1

2

3}

Affiliations

¹ Department of Ophthalmology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, No. 2006, Xiyuan Ave West Hi-Tech Zone, Chengdu, CN 611731, China.
² School of Medicine, University of Electronic Science and Technology of China, No. 2006, Xiyuan Ave West Hi-Tech Zone, Chengdu, CN 611731, China.
³ Sichuan Key Laboratory for Disease Gene Study, Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, No. 32 of the West 2nd Section of First Ring Road, Chengdu 610072, China.
⁴ Southwest Medical University, No. 319, Section 3, Zhongshan Road, Luzhou 646000, China.

Abstract

Purpose: To investigate the effects of accommodation on the geometrical parameters of human lens.

Methods: Eight databases from inception to November 2023 were used for the literature search: CNKI, CBM, VIP, Wan-Fang, PubMed, Web of Science, EMBASE, and the Cochrane Library. The Methodological Index for Non-randomized Studies was used to assess the risk of bias. The PRISMA were followed and the following outcomes were taken into consideration: lens diameter (LD), lens thickness (LT), anterior curvature radius (ACR), posterior curvature radius (PCR), lens center position (LCP), and total cross-sectional area (TCSA). This systematic review was registered on an international platform for registered systematic reviews and meta-analysis (INPLASY202260085).

Results: A total of 19 studies were included. LT increased by 0.04 mm/D (18 studies; 95% confidence interval [CI], 0.03-0.06; I² = 96.6%; P < 0.001). At the same time, LD, ACR, and PCR decreased by 0.06 mm/D (6 studies; 95%CI, -0.07-0.05; I² = 50.1%; P < 0.001), 0.53 mm/D (8 studies; 95%CI, -0.64-0.41; I² = 96.5%; P < 0.001), and 0.14 mm/D (9 studies; 95%CI, -0.19-0.09; I² = 94.7%; P < 0.001) during accommodation, respectively. Moreover, LCP shifted forward by 0.01 mm/D (3 studies; 95%CI, -0.02-0.00; I² = 0.0%; P < 0.001), and TCSA by 0.58 mm²/D (2 studies; 95%CI, 0.41-1.57; I² = 97.0%; P = 0.457) during accommodation.

Conclusions: Changes in LT, LD, ACR, PCR and LCP supported Helmholtz's theory. Different apparatuses or measurement methods influenced the measurement of lens geometrical parameters.

Keywords: Accommodation; Biological parameter; Crystalline lens.