Full-range imaging of eye accommodation by high-speed long-depth range optical frequency domain imaging

Furukawa, Hiroyuki; Hiro-Oka, Hideaki; Satoh, Nobuyuki; Yoshimura, Reiko; Choi, Daeyoung; Nakanishi, M.; Igarashi, Akihito; Ishikawa, Hitoshi; Ohbayashi, Kohji; Shimizu, Kimiya

doi:10.1364/boe.1.001491

Cited by 19 publications

(21 citation statements)

References 38 publications

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“…12, 13, 15–17, 23, 25, 36 The main limitations of commercial FD-OCT implementations are the relatively short axial range and the sensitivity decay with depth, which prevent simultaneous visualization of all the optical components of the anterior segment in a single frame. In the past few years, an effort has been made to increase the imaging depth range and improve the sensitivity performance of FD-OCT systems.…”

Section: Discussionmentioning

confidence: 99%

“…12, 15, 36 SS-OCT with long imaging range (~ 12mm in air) has been demonstrated using high-speed reflective Fabry-Perot tunable lasers (RFPTL) with long coherence length that enables entire anterior segment imaging without the need of complex conjugate removal or switching of the reference arm. 13, 23 A new MEMS-VCSEL light source was recently developed for SS-OCT imaging at ultrahigh imaging rates (60kHz–1MHz) and with very long coherence depth (~50mm) that enables imaging of the entire eye. 41 This advanced SS-OCT implementation could offer significant advantages over the previous systems used for dynamic imaging of the anterior segment but, to the best of our knowledge, a study of dynamic accommodation using this technology has not been reported.…”

Section: Discussionmentioning

confidence: 99%

“…13, 23, 36 The imaging depth of the SS-AS-OCT was not sufficient to image the anterior segment along its entire length, which requires an axial range of about 12mm (in air). Figure 1.1 and 1.2 show OCT vertical B-scans of the anterior segment of the eye representing the anterior (Figure 1.1) and posterior (Figure 1.2) portion of the anterior segment, respectively.…”

Section: Methodsmentioning

confidence: 99%

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Dynamic imaging of accommodation by swept-source anterior segment optical coherence tomography

Néri¹,

Ruggeri²,

Protti³

et al. 2015

Journal of Cataract and Refractive Surgery

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Purpose To study the accommodation process in normal eyes using a commercially available clinical system based on swept-source anterior-segment optical coherence tomography (SS-AS-OCT). Setting Ophthalmology, University of Parma, Parma, Italy. Design Experimental study. Methods The right eye of 14 healthy volunteers (18–46 years) was analyzed with SS-AS-OCT. The optical vergence of the coaxial fixation target integrated in the OCT device was adjusted during imaging to obtain monocular accommodation stimuli with different amplitudes (ASA: 0, 3, 6 and 9 Diopters). Overlapping of real and conjugate OCT images enabled imaging of all the anterior segment optical surfaces in a single frame. Intraocular distances including central corneal thickness (CCT), anterior chamber depth (ACD) and lens thickness (LT) were extracted from the OCT scans acquired at different static ASA. Dynamic analysis of the crystalline lens was also performed during accommodation and disaccommodation by sequentially acquiring OCT images of the anterior segment at a rate of 8 frames per second. LT was extracted from the temporal sequence of OCT images and plotted as a function of time. Results With accommodation ACD decreased significantly (p<0.05), LT increased (p<0.001) and lens central point moved slightly forward (p<0.01). CCT and ACW measurements did not change significantly with accommodation, which in turn confirmed that centering of the eye in the OCT images was maintained through ASA. LT at 0D was positively correlated with age (range: 3.131–4.088mm, r=0.772, p<0.01). Conclusions High-resolution real-time imaging and biometry of the accommodating anterior segment can be effectively performed with a commercial SS-AS-OCT clinical device.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Dynamic imaging of accommodation by swept-source anterior segment optical coherence tomography

Néri¹,

Ruggeri²,

Protti³

et al. 2015

Journal of Cataract and Refractive Surgery

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“…OCT imagery based on a swept light source also achieves long scan depths. 27,28 We previously developed a dual-channel dual-focus OCT system for imaging structural changes that occur during accommodation. 19 However that system required two spectrometers to achieve long scan depths, and the attenuation of 50% of the reflected light resulted in low image contrast.…”

Section: Discussionmentioning

confidence: 99%

Anterior Segment Biometry during Accommodation Imaged with Ultralong Scan Depth Optical Coherence Tomography

Shen

et al. 2012

Ophthalmology

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Purpose To measure by ultra-long scan depth optical coherence tomography (UL-OCT) dimensional changes in the anterior segment of human eyes during accommodation. Design Evaluation of diagnostic test or technology. Participants Forty-one right eyes of healthy subjects with a mean age of 34 years (range, 22–41 years) and a mean refraction of −2.5±2.6 diopters (D) were imaged in two repeated measurements at minimal and maximal accommodation. Methods A specially adapted designed UL-OCT instrument was used to image from the front surface of the cornea to the back surface of the crystalline lens. Custom software corrected the optical distortion of the images and yielded the biometric measurements. The coefficient of repeatability (COR) and the intraclass correlation coefficient (ICC) were calculated to evaluate the repeatability and reliability. Main Outcome Measures Anterior segment parameters and associated repeatability and reliability upon accommodation. The dimensional results included central corneal thickness (CCT), anterior chamber depth and width (ACD, ACW), pupil diameter (PD), lens thickness (LT), anterior segment length (ASL=ACD+LT), lens central position (LCP=ACD+1/2LT) and horizontal radii of the lens anterior and posterior surface curvatures (LAC, LPC). Results Repeated measurements of each variable within each accommodative state did not differ significantly (P>0.05). The CORs and ICCs for CCT, ACW, ACD, LT, LCP, and ASL were excellent (1.2% to 3.59% and 0.998 to 0.877, respectively). They were higher for PD (18.90% to 21.63% and 0.880 to 0.874, respectively), and moderate for LAC and LPC (34.86% to 42.72% and 0.669 to 0.251, respectively) in the two accommodative states. Compared to minimal accommodation, PD, ACD, LAC, LPC, and LCP decreased and LT and ASL increased significantly at maximal accommodation (P<0.05), while CCT and ACW did not change (P>0.05). Conclusions UL-OCT measured changes in anterior segment dimensions during accommodation with good repeatability and reliability. During accommodation, the back surface of the lens became steeper as the lens moved forward.

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“…Generally, there are two types of Fourier domain OCT: swept light source OCT (SS-OCT) and spectral domain OCT (SD-OCT). SS-OCT offers a significant advantage by extending the depth range with only a small loss of sensitivity [6–8]. High-speed multiple ophthalmic applications in one instrument utilizing vertical-cavity surface emitting laser (VCSEL) SS-OCT have been reported [9].…”

Section: Introductionmentioning

confidence: 99%

Versatile optical coherence tomography for imaging the human eye

Tao

Shao

Zhong

et al. 2013

Biomed. Opt. Express

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We demonstrated the feasibility of a CMOS-based spectral domain OCT (SD-OCT) for versatile ophthalmic applications of imaging the corneal epithelium, limbus, ocular surface, contact lens, crystalline lens, retina, and full eye in vivo. The system was based on a single spectrometer and an alternating reference arm with four mirrors. A galvanometer scanner was used to switch the reference beam among the four mirrors, depending on the imaging application. An axial resolution of 7.7 μm in air, a scan depth of up to 37.7 mm in air, and a scan speed of up to 70,000 A-lines per second were achieved. The approach has the capability to provide high-resolution imaging of the corneal epithelium, contact lens, ocular surface, and tear meniscus. Using two reference mirrors, the zero delay lines were alternatively placed on the front cornea or on the back lens. The entire ocular anterior segment was imaged by registering and overlapping the two images. The full eye through the pupil was measured when the reference arm was switched among the four reference mirrors. After mounting a 60 D lens in the sample arm, this SD-OCT was used to image the retina, including the macula and optical nerve head. This system demonstrates versatility and simplicity for multi-purpose ophthalmic applications.

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Full-range imaging of eye accommodation by high-speed long-depth range optical frequency domain imaging

Cited by 19 publications

References 38 publications

Dynamic imaging of accommodation by swept-source anterior segment optical coherence tomography

Dynamic imaging of accommodation by swept-source anterior segment optical coherence tomography

Anterior Segment Biometry during Accommodation Imaged with Ultralong Scan Depth Optical Coherence Tomography

Versatile optical coherence tomography for imaging the human eye

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