A5028392802- Ophthalmology and Visual Impairment Studies
- Retinal Development and Disorders
- Ocular and Laser Science Research
- Retinal Diseases and Treatments
- Visual perception and processing mechanisms
- Corneal surgery and disorders
- Optical Imaging and Spectroscopy Techniques
- Photoreceptor and optogenetics research
- Glaucoma and retinal disorders
- Orthopedic Surgery and Rehabilitation
- Elbow and Forearm Trauma Treatment
- Health and Medical Studies
- Optical measurement and interference techniques
- Retinal and Optic Conditions
- Advanced Fluorescence Microscopy Techniques
- Mesenchymal stem cell research
- Adaptive optics and wavefront sensing
- Optical Coherence Tomography Applications
- Bone fractures and treatments
- Shoulder Injury and Treatment
- Advanced Optical Imaging Technologies
- Healthcare Systems and Challenges
- Electrospun Nanofibers in Biomedical Applications
- Medical and Biological Ozone Research
- Image Processing Techniques and Applications
Johannes Gutenberg University Mainz
2010-2023
University Medical Center of the Johannes Gutenberg University Mainz
2010-2023
University of Tübingen
2018-2023
University of Bayreuth
2023
University of Rochester
2015-2020
Anstalt für Verbrennungskraftmaschinen List (Austria)
2020
Center for Visual Communication (United States)
2019
Sana Kliniken Leipziger Land
2017
Virtual Vehicle (Austria)
2015
Universidad de Murcia
2009-2014
Although imaging of the living retina with adaptive optics scanning light ophthalmoscopy (AOSLO) provides microscopic access to individual cells, such as photoreceptors, retinal pigment epithelial and blood cells in vasculature, other important cell classes, ganglion have proven much more challenging image. The near transparency inner is advantageous for vision, must pass through them reach but it has prevented from being directly imaged vivo. Here we show that somas neurons within (RGC)...
The aim of this study was to assess the impact advanced technology new ExAblate 2100 system (Insightec Ltd, Haifa, Israel) for magnetic resonance imaging (MRI)-guided focused ultrasound surgery on treatment outcomes in patients with symptomatic uterine fibroids, as measured by nonperfused volume ratio.This is a retrospective analysis 115 women (mean age, 42 years; range, 27-54 years) fibroids who consecutively underwent MRI-guided single center generation from November 2010 June 2011. Mean ±...
Purpose.: To investigate binocular visual acuity and depth of focus when one eye forms images through a typical pupil diameter aperture (4 mm) the other small 1.5-mm diameter. Methods.: Using recently developed adaptive optics simulator, monocular were measured in three subjects under specially simulated conditions: right eyes had "small aperture" vision left normal 4-mm The measurements performed photopic mesopic conditions. Results.: An increase (for small-aperture eye) was with respect to...
Some of the different currently applied approaches that correct presbyopia may reduce stereovision. In this work, stereo-acuity was measured for two methods: (1) monovision and (2) small aperture inlay in one eye. When performing experiment, a prototype binocular adaptive optics vision analyzer employed. The system allowed simultaneous measurement manipulation both eyes subject. apparatus incorporated programmable spatial light modulators: phase-only device using liquid crystal on silicon...
The retinoid cycle maintains vision by regenerating bleached visual pigment through metabolic events, the kinetics of which have been difficult to characterize in vivo. Two-photon fluorescence excitation has used previously track autofluorescence directly from retinoids and pyridines mouse frog retinas, but mechanisms are not well understood primates.We developed a two-photon adaptive optics scanning light ophthalmoscope dedicated vivo imaging anesthetized macaques. Using pulsed at 730 nm,...
We present a binocular adaptive optics vision analyzer fully capable of controlling both amplitude and phase the two complex pupil functions in each eye subject. A special feature instrument is its comparatively simple setup. single reflective liquid crystal on silicon spatial light modulator working pure modulation generates profiles for pupils simultaneously. In addition, another transmission operates intensity to produce large variety masks eye. Subjects perform visual tasks through any...
Abstract Correction of spherical (SA) and longitudinal chromatic aberrations (LCA) significantly improves monocular visual acuity (VA). In this work, the effect SA correction in polychromatic monochromatic light on binocular performance is investigated. A liquid crystal based adaptive optics analyzer capable operating employed study. Binocular VA when corrected LCA effects are reduced separately combination, resulting highest value for light. However, summation ratio baseline condition...
Two-photon ophthalmoscopy has potential for in vivo assessment of function normal and diseased retina. However, light safety the sub-100 fs laser typically used is a major concern standards are not well established. To test feasibility safe two-photon excitation fluorescence (TPEF) imaging photoreceptors humans, we examined effects ultrashort pulsed required levels with variety clinical high resolution methods macaques. The only measure that revealed significant effect due to exposure within...
Purpose Eyes with distant objects in focus daylight are thought to become myopic dim light. This phenomenon, often called "night myopia" has been studied extensively for several decades. However, despite its general acceptance, magnitude and causes still controversial. A series of experiments were performed understand night myopia greater detail. Methods We used an adaptive optics instrument operating invisible infrared light elucidate the actual main causes. The experimental setup allowed...
Corneal small aperture inlays provide extended depth of focus as a solution to presbyopia.As this procedure is becoming more popular, it interesting compare its performance with traditional approaches, such monovision.Here, binocular visual acuity was measured function object vergence in three subjects by using adaptive optics vision analyzer.Visual at two luminance levels (photopic and mesopic) under several optical conditions: 1) natural (4 mm pupils, best corrected distance vision), 2)...
Purpose: Two-photon excited fluorescence (TPEF) imaging has potential as a functional tool for tracking visual pigment regeneration in the living eye. Previous studies have shown that all-trans-retinol is likely chief source of time-varying TPEF from photoreceptors. Endogenous retinol could provide specificity desired cycle. However, vivo characterization native kinetics complicated by stimulation beam. We developed an scheme overcoming these challenges and monitored formation clearance...
Purpose: Infrared ultrashort pulse lasers are becoming increasingly popular for applications in the living eye. However, safety standards not yet well established. Here we investigate retinal damage close to threshold this regime macaque Methods: Retinal radiant exposures between 214 and 856 J/cm2 were delivered photoreceptor layer with an laser (730 nm, 55 fs, 80 MHz) through a two-photon adaptive optics scanning light ophthalmoscope. followed up immediately after over several weeks...
The extent to which monocular visual performance of subjects with normal amounts ocular aberrations can be improved adaptive optics (AO) depends on both the pupil diameter and luminance for testing. Here, benefit correction higher order binocular was assessed over a range luminances natural light-adapted sizes AO simulator. Results show that aberration benefits acuity contrast sensitivity increase decreasing luminances. Also, advantage viewing increases when becomes worse. findings suggest...
Purpose: The development of new approaches to human vision restoration could be greatly accelerated with the use nonhuman primate models; however, there is a paucity models outer retina degeneration good spatial localization. To limit ablation photoreceptors, we developed approach that uses near-infrared ultrafast laser, focused using adaptive optics, concentrate light in small focal volume within retina. Methods: In eyes eight anesthetized macaques, 187 locations were exposed laser powers...
A dual setup composed of a point diffraction interferometer (PDI) and Hartmann-Shack (HS) wavefront sensor was built to compare the estimates aberrations provided by two different complementary techniques when applied phase plates. Results show that under same experimental fitting conditions both provide similar information concerning aberration map. When taking into account all Zernike terms up 6th order, maximum difference in root-mean-square error 0.08 μm, this reduced 0.03 μm excluding...
Bone morphogenetic protein 2 (BMP-2) is a potent osteoinductive cytokine and growing number of in vitro studies analyze its effects on human mesenchymal stem cells (hMSC) derived from aged or osteoporotic donors.In these the exact quantification osteogenic differentiation capacity fundamental interest.Nevertheless, experimental conditions for hMSC have not been evaluated systematically vary to considerable extend.Aim study was assess influence cell density, media (ODM) change intervals...
Wave aberrations of isolated ex vivo porcine crystalline lenses were measured by using a point-diffraction interferometer. This method allowed us to gain greater insight into the detailed aberration structure eye showing systematic presence some dominant aberrations. In order significance, astigmatism together with spherical aberration, coma, and trefoil are main present in all lenses. We found high correlation between axis both Y-shaped suture planes lens, revealing subtle relationship...
Night myopia, which is a shift in refraction with light level, has been widely studied but still lacks complete understanding. We used new infrared open-view binocular Hartmann-Shack wave front sensor to quantify night myopia under monocular and natural viewing conditions. Both eyes' accommodative response, aberrations, pupil diameter, convergence were simultaneously measured at levels ranging from photopic scotopic conditions total darkness. For vision, reducing the stimulus luminance...