Variability in Bleach Kinetics and Amount of Photopigment between Individual Foveal Cones

Bedggood, Phillip; Metha, Andrew

doi:10.1167/iovs.11-8796

Cited by 36 publications

(56 citation statements)

References 37 publications

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“…In recent years, there have been several studies focused on observation of the reflectance of living cones [9,[11][12][13][14][15][16]18], and on its modelling, suggesting how the cone reflectance could be due to constructive interference of scattered light which increases with penetration depth in the cone outer segment [30], but the origin of its variability is still not fully understood. The reflectance studies have been performed with all AO imaging modalities, including AO-SLO [11][12][13]16], AO-OCT [14] and flood-illuminated AO cameras [9,17,24].…”

Section: Discussionmentioning

confidence: 99%

“…The reflectance studies have been performed with all AO imaging modalities, including AO-SLO [11][12][13]16], AO-OCT [14] and flood-illuminated AO cameras [9,17,24]. The most common explanation so far for the cone reflectance variability of the order of an hour is the disc renewal process [9], which is thought to be the cause of both change in the outer segment length, observable through interference produced with a long-coherence light source AO-SLO [12], and in the refractive index at the interface between the inner and the outer segment, observable also with a short-coherence light source AO-SLO-OCT [14].…”

Section: Discussionmentioning

confidence: 99%

“…Additional frames were acquired at 1.0 degree only for the flat-field estimation as this eccentricity would not have been suitable for the cone analysis (section 2.1). The frames were averaged unregistered, so that the major retinal structures, such as blood vessels, are averaged out, as in previous works [12,16]. All the raw frames were divided by the same flat-field image and then registered in order to produce the final images.…”

Section: Image Pre-processing and Processingmentioning

confidence: 99%

“…In addition to their number and position, one of the most noticeable features of the photoreceptors is the spatial variability of their reflectance, which has been clearly detected with all AO imaging modalities [9][10][11][12][13][14][15][16][17][18]. From early observations, it has been shown that the cones change their reflectance with time even in healthy retinas [9].…”

Section: Introductionmentioning

confidence: 99%

“…It has been shown that the changes in reflectance occur independently between the cones [9] and that the cones change their brightness on time scales ranging from milliseconds [10,17] and seconds [11,15,16] to hours [9,12,13], days [14], months or years [18].…”

Section: Introductionmentioning

confidence: 99%

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Understanding the changes of cone reflectance in adaptive optics flood illumination retinal images over three years

Mariotti¹,

Devaney²,

Lombardo³

et al. 2016

Biomed. Opt. Express

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Abstract:Although there is increasing interest in the investigation of cone reflectance variability, little is understood about its characteristics over long time scales. Cone detection and its automation is now becoming a fundamental step in the assessment and monitoring of the health of the retina and in the understanding of the photoreceptor physiology. In this work we provide an insight into the cone reflectance variability over time scales ranging from minutes to three years on the same eye, and for large areas of the retina (≥ 2.0 × 2.0 degrees) at two different retinal eccentricities using a commercial adaptive optics (AO) flood illumination retinal camera. We observed that the difference in reflectance observed in the cones increases with the time separation between the data acquisitions and this may have a negative impact on algorithms attempting to track cones over time. In addition, we determined that displacements of the light source within 0.35 mm of the pupil center, which is the farthest location from the pupil center used by operators of the AO camera to acquire high-quality images of the cone mosaic in clinical studies, does not significantly affect the cone detection and density estimation.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Image Pre-processing and Processingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Understanding the changes of cone reflectance in adaptive optics flood illumination retinal images over three years

Mariotti¹,

Devaney²,

Lombardo³

et al. 2016

Biomed. Opt. Express

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Adaptive optics optical coherence tomography in glaucoma

Dong

Wollstein

Wang

et al. 2017

Progress in Retinal and Eye Research

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Since the introduction of commercial optical coherence tomography (OCT) systems, the ophthalmic imaging modality has rapidly expanded and it has since changed the paradigm of visualization of the retina and revolutionized the management and diagnosis of neuro-retinal diseases, including glaucoma. OCT remains a dynamic and evolving imaging modality, growing from time-domain OCT to the improved spectral-domain OCT, adapting novel image analysis and processing methods, and onto the newer swept-source OCT and the implementation of adaptive optics (AO) into OCT. The incorporation of AO into ophthalmic imaging modalities has enhanced OCT by improving image resolution and quality, particularly in the posterior segment of the eye. Although OCT previously captured in-vivo cross-sectional images with unparalleled high resolution in the axial direction, monochromatic aberrations of the eye limit transverse or lateral resolution to about 15-20 μm and reduce overall image quality. In pairing AO technology with OCT, it is now possible to obtain diffraction-limited resolution images of the optic nerve head and retina in three-dimensions, increasing resolution down to a theoretical 3 μm3. It is now possible to visualize discrete structures within the posterior eye, such as photoreceptors, retinal nerve fiber layer bundles, the lamina cribrosa, and other structures relevant to glaucoma. Despite its limitations and barriers to widespread commercialization, the expanding role of AO in OCT is propelling this technology into clinical trials and onto becoming an invaluable modality in the clinician's arsenal.

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Adaptive optics imaging of the human retina

Burns

Elsner

Sapoznik

et al. 2019

Progress in Retinal and Eye Research

173

132

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Adaptive Optics (AO) retinal imaging has provided revolutionary tools to scientists and clinicians for studying retinal structure and function in the living eye. From animal models to clinical patients, AO imaging is changing the way scientists are approaching the study of the retina. By providing cellular and subcellular details without the need for histology, it is now possible to perform large scale studies as well as to understand how an individual retina changes over time. Because AO retinal imaging is non-invasive and when performed with near-IR wavelengths both safe and easily tolerated by patients, it holds promise for being incorporated into clinical trials providing cell specific approaches to monitoring diseases and therapeutic interventions. AO is being used to enhance the ability of OCT, fluorescence imaging, and reflectance imaging. By incorporating imaging that is sensitive to differences in the scattering properties of retinal tissue, it is especially sensitive to disease, which can drastically impact retinal tissue properties. This review examines human AO retinal imaging with a concentration on the use of the Adaptive Optics Scanning Laser Ophthalmoscope (AOSLO). It first covers the background and the overall approaches to human AO retinal imaging, and the technology involved, and then concentrates on using AO retinal imaging to study the structure and function of the retina.

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Variability in Bleach Kinetics and Amount of Photopigment between Individual Foveal Cones

Abstract: Neighboring cones in the fovea display high variability in their optical properties.

Cited by 36 publications

References 37 publications

Understanding the changes of cone reflectance in adaptive optics flood illumination retinal images over three years

Understanding the changes of cone reflectance in adaptive optics flood illumination retinal images over three years

Adaptive optics optical coherence tomography in glaucoma

Adaptive optics imaging of the human retina

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