High-resolution retinal imaging with adaptive optics was used to record the position of a light stimulus on cone mosaic, an error at least five times smaller than diameter smallest foveal cones. We discuss factors that limit accuracy which absolute can be determined. In subjects, standard deviation fixation positions measured in discrete trials ranged from 2.1 6.3 arcmin, average 3.4 arcmin (about 17 μm), agreement previous studies (R. W. Ditchburn, 1973; R. M. Steinman, G. Haddad, A....

To relate in vivo microscopic retinal changes to visual function patients who have various forms of dystrophy.The UC Davis Adaptive Optics (AO) fundus camera was used acquire images at the cellular level. Visual tests consisting fields, multifocal electroretinography (mfERG), and contrast sensitivity were measured all subjects by using stimuli that coincident with areas imaged. Five different dystrophy three control recruited. Cone densities quantified for images.In diseased retinas, there...

<h3>Aims</h3> It is well established that glaucoma results in a thinning of the inner retina. To investigate whether outer retina also involved, ultrahigh-resolution retinal imaging techniques were utilised. <h3>Methods</h3> Eyes from 10 patients (25–78 years old), imaged using three research-grade instruments: (1) Fourier-domain optical coherence tomography (UHR-FD-OCT), (2) adaptive optics (AO) UHR-FD-OCT and (3) AO-flood illuminated fundus camera (AO-FC). AO-UHR-FD-OCT B-scans examined...

Ophthalmic instrumentation equipped with adaptive optics offers the possibility of rapid and automated correction eye's for improving vision images retina. One factor that limits widespread implementation is cost wave-front corrector, such as a deformable mirror. In addition, large apertures these elements require high pupil magnification, hence systems tend to be physically large. We present what are believed first closed-loop results when compact, low-cost, surface micromachined,...

Abstract Glaucoma is a progressive neurodegenerative disease characterized by the gradual degeneration of retinal ganglion cells, leading to irreversible blindness worldwide. Therefore, timely and accurate diagnosis glaucoma crucial, enabling early intervention facilitating effective management mitigate further vision deterioration. The advent optical coherence tomography (OCT) has marked transformative era in ophthalmology, offering detailed visualization macula optic nerve head (ONH)...

A fast and efficient method for quantifying photoreceptor density in images obtained with an en-face flood-illuminated adaptive optics (AO) imaging system is described. To improve accuracy of cone counting, are analyzed over extended areas. This achieved two separate semiautomated algorithms: (1) a montaging algorithm that joins retinal overlapping common features without edge effects (2) measurement counts the individual cones montaged image. The high, >97% agreement simulated image (of...

Recent years have seen remarkable results in high-resolution imaging and testing of the human visual system. The ability to obtain vivo images fundus on micrometer scale will allow for much earlier diagnosis treatment a range retina diseases. These advances been made possible part through use adaptive optics (AO). In order utilize full numerical aperture and, hence, maximize resolution eye, it is necessary provide means correcting all ocular aberrations. concept AO has used successfully...

The contributions of optical and neural factors to age-related losses in spatial vision are not fully understood. We used closed-loop adaptive optics test the visual benefit correcting monochromatic high-order aberrations (HOAs) on for observers ranging age from 18 81 years. Contrast sensitivity was measured monocularly using a two-alternative forced-choice (2AFC) procedure sinusoidal gratings over 6 mm 3 pupil diameters. Visual acuity 4AFC procedure. Over pupil, young showed large AO at...

Although single cone receptors have been imaged in vivo, to our knowledge there has no observation of rods the living normal eye. Using an adaptive optics ophthalmoscope and post processing, evidence a rod mosaic was observed at 5° 10° eccentricities horizontal temporal retina. For four human subjects, small structures were between larger cones repeatedly same locations on different days, with varying wavelengths. Image analysis gave spacings that agree well measurements from histological data.

Numerous types of wavefront correctors have been employed in adaptive optics (AO) systems for correcting the ocular aberration. While all improved image quality, none yielded diffraction-limited imaging large pupils (>/=6 mm), where aberrations are most severe and benefit AO greatest. To this end, we modeled performance discrete actuator, segmented piston-only, piston/tip/tilt conjunction with measured on normal human eyes two populations. The error was found to be as 53 microm, depending...

Adaptive optics-optical coherence tomography (AO-OCT) allows for the three-dimensional visualization of retinal ganglion cells (RGCs) in living human eye. Quantitative analyses RGCs have significant potential improving diagnosis and monitoring diseases such as glaucoma. Recent advances machine learning (ML) made possible automatic identification analysis within complex volumes obtained with imaging. However, current state-of-the-art ML approach relies on fully supervised training, which...

A full-field swept-source optical coherence tomography (FF-SS-OCT) for in vivo murine retinal imaging is demonstrated. The on-axis FF-SS-OCT system was built a Mach-Zehnder interferometer configuration employing tunable laser source with an adjustable sweep rate and range conjunction fast 2D-CMOS camera. large field (coherent) illumination accomplished using interface comprised of short-focal length lens contact lens. magnification between the camera retina (spatial sampling) appropriately...

We have designed and implemented a dual-mode adaptive optics (AO) imaging system that combines spectral domain optical coherence tomography (OCT) scanning laser ophthalmoscopy (SLO) for in vivo of the human retina. The simultaneously acquires SLO frames OCT B-scans at 60 Hz with an volume acquisition time 4.2 s. Transverse eye motion measured from is used to register generate three-dimensional (3-D) volumes. Key design considerations include: minimizing aberrations through use off-axis relay...

A high-speed, adaptive optics partially confocal multi-spot ophthalmoscope (AO-pcMSO) using a digital micromirror device (DMD) in the illumination channel and fast 2D CMOS camera is described. The synchronized with DMD allowing projection of multiple, simultaneous AO-corrected spots onto human retina. Spatial filtering on each raw retinal image before reconstruction works as an array virtual pinholes. frame acquisition rate 250 fps achieved by applying this parallel scheme. contrast improves...

High-speed, phase contrast retinal and blood flow imaging using an adaptive optics partially confocal multi-line ophthalmosocope (AO-pcMLO) is described. It allows for simultaneous with various directional illumination by a single 2D camera digital micromirror device (DMD). Both vertical horizontal line directions were tested, photoreceptor vascular imaging. The provided improved visualization of structures such as cone inner segments, vessel walls red cells images being acquired at frame...

Differential optical transfer function (dOTF) is an image-based, noniterative wavefront sensing method that uses two star images with a single small change in the pupil. We describe possible methods for introducing required pupil modification to James Webb Space Telescope, one using (<λ/4) displacement of segment's actuator and another misalignments NIRCam's filter wheel. While both should work NIRCam, will allow MIRI NIRISS be used segment phasing, which new functionality. Since requires...

Purpose: The chick eye is extensively used as a model in the study of myopia and its progression; however, analysis photoreceptor mosaic has required use excised retina due to uncorrected optical aberrations lens cornea. This implemented high resolution adaptive optics (AO) retinal imaging visualize cone vivo.

To examine the microstructural changes in inner nuclear layer (INL) and ganglion cell (GCL) a primary open-angle glaucoma (POAG) subject at 2 timepoints, 4 months apart.This case-control study (1 POAG 1 normal control) used single cell, 3-dimensional volumetric imaging capability of an adaptive optics-optical coherence tomography-scanning laser ophthalmoscopy system to retina.At area greatest glaucomatous change [3-degrees temporal (T), 3-degrees inferior (I), right eye], GCL was greatly...

BACKGROUND AND OBJECTIVE: Subthreshold micropulse laser (SML) treatment at 577 nm has been proposed as a safe and efficacious therapy for diabetic macular edema (DME). The study objective was to evaluate the integrity of individual cone photoreceptors after SML using high-resolution retinal imaging. PATIENTS METHODS: An observational cohort four subjects with DME treated followed over time. Cone inner outer segment lengths total thicknesses (TRT) were measured resolved. primary outcome...

To evaluate the influence of spherical aberration on contrast sensitivity using adaptive optics.Vision Science and Advanced Retinal Imaging Laboratory, Department Ophthalmology & Vision Science, University California, Davis Medical Center, Sacramento, USA.Contrast at 8 cycles per degree was evaluated an optics system that permitted aberrations to be measured with a Hartmann-Shack wavefront sensor controlled by 109 actuator continuous-surface deformable mirror plane conjugate observer's...

In images of the human fundus, fraction total returning light that comes from choroidal layers behind retina increases with wavelength [Appl. Opt.28, 1061 (1989); Vision Res.36, 2229 (1996) ]. There is also evidence originating receptors not coupled into receptor waveguides en route to pupil [S. A. Burns et al., Noninvasive Assessment Visual System, Vol. 11 1997 Trends in Optics and Photonics Series, D. Yager, ed. (Optical Society America, 1997), p. a1; Invest. Ophthalmol. Sci.38, 1657...