Developments in contact lens measurement: A comparative study of industry standard geometric inspection and optical coherence tomography

“…To date no studies have assessed the integrity of the lenses and the ocular surface during and after lens use . Therefore, this study sought to assess in vivo changes in contact lens thickness of a high water content hydrogel lens, compared with two other silicone hydrogel daily disposable contact lenses.…”

mentioning

confidence: 99%

Impact of contact lens material and design on the ocular surface

Ruiz-Alcocer

Monsálvez-Romín

García‐Lázaro

et al. 2018

Clinical and Experimental Optometry

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“…The Optimec is830 SD-OCT system was used for the OCT characterization. This system is equipped with a super luminescent diode (SLD) light source and a fiber coupler acting as a beam splitter divides the light between the sample and the reference arm [7]. A spectrometer was used to analyze the return reflection combined between the reference arm and the sample scanned by a micro-electrical mechanical (MEMs) mirror system [7].…”

Section: Methodsmentioning

confidence: 99%

Femtosecond laser inscribed advanced calibration phantom for optical coherence tomography (OCT)

Lü

Gordon

Coldrick³

et al. 2020

Advanced Fabrication Technologies for Micro/Nano Optics and Photonics XIII

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Optical coherence tomography (OCT) has developed rapidly and is widely used in different fields such as biomedicine and optometry. The characterization and calibration of OCT systems is essential when testing the system and during normal use to ensure that there is no misalignment or distortion that could affect clinical decisions. Imaging distortion is a significant challenge for OCT systems when viewing through non-planar surfaces. Here we present a new multipurpose plano-convex OCT phantom which is designed to be used for OCT characterization and calibration as well as to validate the post-processing algorithm for the imaging distortion of the OCT systems. A femtosecond laser direct writing technique is used to fabricate this phantom which consists of a landmark layer with radial lines at a 45-degree angular spacing inscribed at 50μm in apparent depth (AD) underneath the planar surface. Below that there are a further 8 layers of a spherical inscription pattern which has a 150μm (in AD) separation between each layer. The first spherical layer is located at 150μm (in AD) underneath the planar surface. Due to the laser power loss when travelling through the deeper layer, an increased power is applied to the deeper layers. The spherical pattern overcomes orientation issues seen with existing calibration phantoms. The landmark layer is applied so that it can easily tell the exact location when scanning which will also benefit the image distortion correction process.

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“…An OCT-based instrument also allowed multiple geometric parameters of CL in a single device to be investigated and provided the ability to measure geometric data, such as sagittal depth and thickness at the center and periphery of the lens. The benefits in terms of measurement time (about 35 s) strongly suggest that SSOCT may be an attractive method for measuring CLs [61].…”

Section: Metrologymentioning

confidence: 99%

Developments in Contact Lens Imaging: New Applications of Optical Coherence Tomography

et al. 2019

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Optical coherence tomography (OCT) is a high-speed and non-contact optical imaging technology widely used for noninvasive cross-sectional imaging of biological objects. Two main OCT technologies have been developed: time domain and Fourier domain technologies. The latter can be further divided into spectral domain OCT, which uses a broadband light source and a spectrometer as a detector, and swept source OCT, which employs a quickly-rotating laser source. Advances in OCT technology have made it one of the most helpful devices in ophthalmic practice. Fourier OCT has revolutionized imaging of the posterior segment of the eye, as well as of anterior structures and has enhanced the ability to diagnose and manage patients. It provides high-resolution information about the tear film, contact lens (CL), a qualitative and quantitative assessment of the anterior eye that is important in contact lens fitting, and allows possible eye surface changes while wearing contact lenses to be monitored. Potential swept source OCT technology applications include industrial processes of lens design and quality control. In this paper, we describe clinical applications and outline a variety of multifunctional uses of OCT in the field of refractive error correction with contact lenses.

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Developments in contact lens measurement: A comparative study of industry standard geometric inspection and optical coherence tomography

Abstract: The OCT based instrument assessed in this study is able to match and improve on the JCF instrument for the measurement of total diameter, back optic zone radius and centre thickness for soft contact lenses in temperature controlled saline.

Cited by 19 publications

References 11 publications

Impact of contact lens material and design on the ocular surface

Impact of contact lens material and design on the ocular surface

Femtosecond laser inscribed advanced calibration phantom for optical coherence tomography (OCT)

Developments in Contact Lens Imaging: New Applications of Optical Coherence Tomography

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