Current Eye Research, 2014; 39(6): 611–619
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Informa Healthcare USA, Inc.
ISSN: 0271-3683 print / 1460-2202 online
DOI: 10.3109/02713683.2013.860991
ORIGINAL ARTICLE
Noninvasive Imaging and Measurement of
Accommodation Using Dual-Channel SD-OCT
Yong Sun
1,3
*, Shanhui Fan
1
*, Haihua Zheng
2
, Cuixia Dai
1
, Qiushi Ren
1
, and
Chuanqing Zhou
1
1
School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China,
2
The Department of
Ophthalmology, The Second affiliated Hospital of Wenzhou Medical College, Wenzhou, China, and
3
The People’s
Hospital of Xinjiang Urgur Autonomous Region, Urumqi, China
ABSTRACT
Purpose: To investigate the feasibility and practicality of real-time noninvasive imaging and measurement of
ocular accommodation (0–5D with one diopter step) using dual-channel, dual-focus spectral domain optical
coherence tomography (SD-OCT).
Materials and Methods: A custom-built, dual-channel, dual-focus SD-OCT was used to image the anterior
segment, including the cornea, iris, and anterior and posterior lens surfaces. Three consecutive measurements
were taken in each accommodative session for each subject. Changes in ocular dimensions during
accommodation were calculated based on the acquired SD-OCT images. A Friedman test was used to test
sensitivity of ocular dimension changes per diopter of accommodation.
Results: With accommodation, anterior chamber depth (ACD), curvature radius of both anterior (RAL) and
posterior (RPL) lens surfaces, and pupil diameter (PD) decreased significantly, whereas lens thickness (LT)
increased significantly (p50.05, Friedman test). Ocular dimensions tended to change according to the
increasing of accommodative stimulus, as did a backward movement of the posterior lens surface.
Conclusions: SD-OCT, via extended imaging depth through a dual-channel, dual-focus approach, is a feasible
and practical modality for noninvasive imaging and measurement of ocular accommodation.
Keywords: Accommodation, anterior segment, lens, optical coherence tomography, refractive error
INTRODUCTION
Accommodation consists of a dioptric change in
power of the eye that allows near objects to be
focused on the retina. The shape and thickness of the
crystalline lens as well as the distances between the
major refractive surfaces are changed during accom-
modation. It is well known that accommodation
mechanism and its relevance with presbyopia or
myopia has been debated for many years.
1–7
Hence,
the fields have attracted extensive research endeavors
in an effort to find therapeutic modalities for
presbyopia and myopia, both of which occur with a
high worldwide incidence.
One of the difficulties in studying the accommo-
dation mechanism lies in the imaging techniques
available for determining in vivo anterior segment
modifications that occur during accommodation.
Conventional technologies for anterior segment
imaging include slit-scanning topography (SST),
ultrasound biomicroscopy (UBM), Scheimpflug
photography, and Purkinje imaging.
8–12
These
modalities require stimulation of the fellow eye in
order to observe variations in the imaged eye.
*These authors contribute equally to this paper
Correspondence: Chuanqing Zhou, PhD, Associate Professor, School of Biomedical Engineering, Shanghai Jiao Tong University, 800
Dong-Chuan Road, Shanghai 200240, China. Tel: +86-21-34204076. Fax: +86-21-34204078. E-mail: zhoucq@sjtu.edu.cn
Haihua Zheng, MD, Professor, Department of Ophthalmology, The Second affiliated Hospital of Wenzhou Medical College, Wenzhou 325027,
China. Tel: +86-577-88002614. Fax: +86-577-88002614. E-mail: zhenghh@wzhealth.com
Received 8 April 2013; revised 28 September 2013; accepted 27 October 2013; published online 8 November 2013
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