Sensorless astigmatism correction using a variable cross-cylinder for high lateral resolution optical coherence tomography in a human retina

Tamura, Masato; Moriguchi, Yoshikiyo; Yeh, Shu-Yun; Matsumoto, Akiko; Shibutani, M.; Asao, Takahiro; Mino, Toshihiro; Nakanishi, Michiko; Kubota, Akira

doi:10.1364/ao.441646

Cited by 4 publications

(3 citation statements)

References 33 publications

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“… Control of the convergence stimulus: The angle of measurement is adjusted by the three motors to realise a convergence stimulus at any distance from 25 cm to 6 m. Control of accommodation stimulus: The spherical lens position is adjusted using one motor to realise accommodation stimuli at any distance from 25 cm to 6 m. Control of spherical power: Spherical lens position is adjusted by one motor to realise any spherical power setting from + 18D to -18D. Control of cylindrical power and cylindrical axis: The rotation angle of the two cylindrical lenses is adjusted by two motors to realise any cylindrical power and cylindrical axis setting from 0D to -8D [ 13 , 14 ]. …”

Section: Methodsmentioning

confidence: 99%

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Evaluation of objective and subjective binocular ocular refraction with looking in type

Fukushima,

Hirota,

Yukimori

et al. 2024

BMC Ophthalmol

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Background This study aimed to compare the results of the Chronos binocular/monocular refraction system, that measures objective and subjective ocular refraction in one unit, to objective findings obtained from a conventional autorefractometer and a conventional subjective ocular refraction using a trial-frame in real space. Methods Twenty-eight healthy volunteers (21.2 ± 1.5 years old) were included in this study. Objective ocular refraction was measured using two tests: the Chronos binocular/monocular refraction system under binocular conditions and a conventional autorefractometer under monocular conditions. Subjective ocular refraction was measured using three tests: Chronos binocular/monocular refraction system under binocular, monocular conditions, and trial-frame in the real space under monocular conditions. The measurement distance was set to 5.0 m for each test. All ocular refractions were converted into spherical equivalents (SEs). Results The objective SE was significantly more negative with Chronos binocular/monocular refraction system under binocular condition (− 4.08 ± 2.76 D) than with the conventional autorefractometer under monocular condition (− 3.85 ± 2.66 D) (P = 0.002). Although, the subjective SE was significantly more negative with Chronos binocular/monocular refraction system under binocular condition (− 3.55 ± 2.67 D) than with the trial-frame in the real space under monocular condition (− 3.33 ± 2.75 D) (P = 0.002), Chronos binocular/monocular refraction system under monocular condition (− 3.17 ± 2.57 D) was not significantly different from that in trial-frame in real space under monocular condition (P = 0.33). Conclusion These findings suggest that the Chronos binocular/monocular refraction system, which can complete both objective and subjective ocular refraction tests in a single unit, is suitable for screening ocular refraction, although it produces slightly more myopic results. Furthermore, subjective ocular refraction testing accuracy in Chronos binocular/monocular refraction system can be equivalent to trial-frame in real-space testing by switching from binocular to monocular condition.

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Section: Methodsmentioning

confidence: 99%

“…Control of cylindrical power and cylindrical axis: The rotation angle of the two cylindrical lenses is adjusted by two motors to realise any cylindrical power and cylindrical axis setting from 0D to -8D [ 13 , 14 ].…”

Section: Methodsmentioning

confidence: 99%

Evaluation of objective and subjective binocular ocular refraction with looking in type

Fukushima,

Hirota,

Yukimori

et al. 2024

BMC Ophthalmol

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“…This study used a high-resolution 400-kHz SS-OCT prototype 23 . The center wavelength of the swept source was 1050 nm with a tuning range of approximately 100 nm, which results in an 8-μm axial resolution.…”

Section: Methodsmentioning

confidence: 99%

Developing quantitative analysis program of blood flow velocity according to vessel diameter for neovascular age-related macular degeneration using OCTA-VISTA

Tanaka,

Mino,

Moriguchi

et al. 2024

Sci Rep

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This study aimed to develop a quantitative analysis program of blood flow velocity by vessel diameter in neovascular age-related macular degeneration (nAMD) subjects using high-speed swept-source optical coherence tomography angiography. This retrospective, observational, cross-sectional study included 10 eyes of healthy volunteers and 4 eyes of patients with representative nAMD. Novel scan patterns and variable interscan time analysis were utilized to measure the flow parameter, a surrogate marker of blood flow velocity, by vessel diameter within different depths. Detected vessels at superficial and deep as well as outer retinal regions were categorized into three vessel diameters (major vessels (> 40 μm), medium vessels (20–40 μm), and capillaries (< 20 μm)). The flow parameter increased with enlarged vessel diameter in all participants at superficial and deep layer. All nAMD subjects, except for type 3 macular neovascularization (MNV), contained a structure dominated by medium vessels at outer retinal region. The mean flow parameter at outer retinal region was type 1 MNV (1.46 ms−1), type 1 + 2 MNV (0.98 ms−1), and polypoidal choroidal vasculopathy, including branching vascular networks (1.46 ms−1). This program provides the possibility to extract the blood flow information at different depths by vessel diameter types, which is considered to be useful tool for evaluating nAMD pathology and activity.

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Extended and adjustable field-of-view of variable interscan time analysis by ammonite-scanning swept-source optical coherence tomography angiography

Mino

Moriguchi²,

Tamura³

et al. 2023

Biomed. Opt. Express

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A novel scanning protocol, ammonite scan, is proposed for widefield optical coherence tomography angiography (OCTA) and relative retinal blood flow velocity imaging in the human retina using variable interscan time analysis (VISTA). A repeated circle scan using a 400 kHz swept-source was employed to achieve an interscan time of 1.28 ms. The center of the repeated circular scan continuously moved spirally towards the peripheral region, ensuring an extended and adjustable scan range while preserving the short interscan time. Image artifacts due to eye movement were eliminated via extra motion-correction processing using data redundancy. The relative blood flow velocity in superficial and deep plexus layers was calculated from the VISTA image, and their ratio was used to explore the microvascular flow parameter in the healthy human eye.

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Sensorless astigmatism correction using a variable cross-cylinder for high lateral resolution optical coherence tomography in a human retina

Cited by 4 publications

References 33 publications

Evaluation of objective and subjective binocular ocular refraction with looking in type

Evaluation of objective and subjective binocular ocular refraction with looking in type

Developing quantitative analysis program of blood flow velocity according to vessel diameter for neovascular age-related macular degeneration using OCTA-VISTA

Extended and adjustable field-of-view of variable interscan time analysis by ammonite-scanning swept-source optical coherence tomography angiography

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