The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Fumiatsu Maeda - One of the best experts on this subject based on the ideXlab platform.
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Color Pupillography in Dorsal Midbrain Syndrome
Journal of Neuro-ophthalmology, 2017Co-Authors: Carina Kelbsch, Torsten Strasser, Tobias Peters, Fumiatsu Maeda, Barbara Wilhelm, Helmut WilhelmAbstract:The purpose of this study was to evaluate the pupil response to chromatic stimuli in patients with lesions in the dorsal midbrain and possibly gain new insights into the afferent pupillary pathways. Color Pupillography was performed in 5 patients with dorsal midbrain syndrome (DMS), and their results were compared with those of 20 healthy control subjects. We used full-field red stimuli (605 nm) that primarily address the rod/cone system and blue stimuli (420 nm) that preferentially activate intrinsically photosensitive retinal ganglion cells (ipRGCs) directly, with a duration of 4 seconds and a stimulus intensity of 28 lx corneal illumination under mesopic conditions. One eye was stimulated, and the consensual pupil response was recorded and analyzed. The pupillary light reflex in patients with DMS was reduced, differed in shape, and showed a prolonged latency time compared to normal subjects. The blue response was less affected than the red response: the mean maximal relative amplitude (M) was 15.8% (SD = 7.8) in patients with DMS compared with 43.0% (SD = 5.5) in normal subjects for red stimulation, and M = 40.8%, SD = 8.4 (DMS) with M = 58.3%, SD = 4.8 (normals) for blue stimulation. The reduction was 63% for red stimulation but only 30% for blue stimulation in patients with DMS. Moreover, there was a preserved postillumination pupil response to blue stimulation in DMS patients. In DMS, the melanopsin-mediated ipRGC pathway appeared relatively preserved.
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chromatic Pupillography in hemianopia patients with homonymous visual field defects
Graefes Archive for Clinical and Experimental Ophthalmology, 2017Co-Authors: Carina Kelbsch, Tobias Peters, Fumiatsu Maeda, Barbara Wilhelm, Torsten Straser, Karolina Skorkovska, Helmut WilhelmAbstract:Purpose The pupil light reflex is considered to be a simple subcortical reflex. However, many studies have proven that patients with isolated occipital lesions with homonymous hemianopia show pupillary hemihypokinesia. Our hypothesis is that the afferent pupillary system consists of two pathways: one via intrinsically photosensitive retinal ganglion cells (ipRGCs), the other running through the normal RGCs via the visual cortex. The purpose of this study was to test the hypothesis of these two separate pupillomotor pathways.
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analysis of retinal function using chromatic Pupillography in retinitis pigmentosa and the relationship to electrically evoked phosphene thresholds
Acta Ophthalmologica, 2017Co-Authors: Carina Kelbsch, Torsten Strasser, Fumiatsu Maeda, Jolanta Lisowska, Lukasz Lisowski, K. Stingl, Barbara WilhelmAbstract:Purpose To analyse pupil responses to specific chromatic stimuli in patients with advanced retinitis pigmentosa (RP) to ascertain whether chromatic Pupillography can be used as an objective marker for residual retinal function. To examine correlations between parameters of the pupil response and the perception threshold of electrically evoked phosphenes. Methods Chromatic Pupillography was performed in 40 patients with advanced RP (visual acuity < 0.02 or visual field ≤5°, non-recordable ERGs) and 40 age-matched healthy subjects. Pupil responses to full-field red (605 nm) and blue (420 nm) stimuli of 28 lx corneal illumination were recorded and analysed for two stimulus durations (1 and 4 seconds). The perception threshold of phosphenes to transcorneal electrostimulation was ascertained and correlated to the pupil responses and visual acuity. Results Patients with RP showed significantly reduced pupil responses to red and blue stimuli compared with the controls. With red stimuli, pupillary escape could be observed; blue stimuli resulted in a well-preserved postillumination pupil response. Phosphene thresholds were significantly increased in patients with RP and correlated with the parameters of the pupil response if all subjects were considered. Within the RP group alone, this relationship was less pronounced and statistically not significant. Conclusions Chromatic Pupillography demonstrated a significant decrease in outer retinal photoreceptor responses but a persisting and disinhibited intrinsic photosensitive retinal ganglion cell function in advanced RP. These phenomena may be useful as an objective marker for the efficacy of any interventional treatment for hereditary retinal diseases as well as for the selection of suitable patients for an electronic retinal implant.
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development of a chromatic Pupillography protocol for the first gene therapy trial in patients with cnga3 linked achromatopsia
Investigative Ophthalmology & Visual Science, 2017Co-Authors: Carina Kelbsch, Fumiatsu Maeda, Jolanta Lisowska, Lukasz Lisowski, Paul Richter, Susanne Kohl, Ditta ZoborAbstract:To establish a feasible and sensitive pupillographic protocol to assess outer and inner retinal function for the first gene therapy trial in achromatopsia patients (ACHM) with mutations in CNGA3.Twenty-seven CNGA3-ACHM patients and 22 age-matched control subjects were tested using chromatic Pupillography. Three different protocols were established to assess the pupillary light reflex parameters and to create the final protocol. In the individual protocols, various stimulus parameters (i.e., intensity, duration, wavelength, adaptation states) were applied to evaluate the impact of these stimuli on the pupillary response in untreated ACHM patients.In the light-adapted conditions, CNGA3-ACHM patients showed significantly reduced maximal amplitudes compared with the control group when using a 1-second high intensity (28-lux corneal illumination) blue or red stimulus (P < 0.005). In the dark-adapted conditions, CNGA3-ACHM patients unexpectedly revealed significantly increased maximal amplitudes when stimulating with red (1 second) or blue (4 ms and 1 second) stimuli of low intensity (0.01-lux corneal illumination; P < 0.05). Pupil responses of CNGA3-ACHM patients after high intensity (28 lux) red and blue 1-second stimuli were within the normal range.Chromatic Pupillography demonstrated significant reduced pupil responses to stimuli addressing primarily cone function, an increased sensitivity to rod-favoring stimuli and evidence for disinhibition of intrinsically photosensitive retinal ganglion cells in CNGA3-ACHM patients. A final protocol was established based on these findings. These conclusions may be useful for the objective assessment of efficacy gained by gene therapy or other innovative interventions in this hereditary retinal disorder.
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Analysis of retinal function using chromatic Pupillography in retinitis pigmentosa and the relationship to electrically evoked phosphene thresholds
Acta Ophthalmologica, 2016Co-Authors: Carina Kelbsch, Torsten Strasser, Fumiatsu Maeda, Jolanta Lisowska, Lukasz Lisowski, K. Stingl, Barbara Wilhelm, Helmut Wilhelm, Tobias PetersAbstract:Purpose To analyse pupil responses to specific chromatic stimuli in patients with advanced retinitis pigmentosa (RP) to ascertain whether chromatic Pupillography can be used as an objective marker for residual retinal function. To examine correlations between parameters of the pupil response and the perception threshold of electrically evoked phosphenes. Methods Chromatic Pupillography was performed in 40 patients with advanced RP (visual acuity
Barbara Wilhelm - One of the best experts on this subject based on the ideXlab platform.
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Color Pupillography in Dorsal Midbrain Syndrome
Journal of Neuro-ophthalmology, 2017Co-Authors: Carina Kelbsch, Torsten Strasser, Tobias Peters, Fumiatsu Maeda, Barbara Wilhelm, Helmut WilhelmAbstract:The purpose of this study was to evaluate the pupil response to chromatic stimuli in patients with lesions in the dorsal midbrain and possibly gain new insights into the afferent pupillary pathways. Color Pupillography was performed in 5 patients with dorsal midbrain syndrome (DMS), and their results were compared with those of 20 healthy control subjects. We used full-field red stimuli (605 nm) that primarily address the rod/cone system and blue stimuli (420 nm) that preferentially activate intrinsically photosensitive retinal ganglion cells (ipRGCs) directly, with a duration of 4 seconds and a stimulus intensity of 28 lx corneal illumination under mesopic conditions. One eye was stimulated, and the consensual pupil response was recorded and analyzed. The pupillary light reflex in patients with DMS was reduced, differed in shape, and showed a prolonged latency time compared to normal subjects. The blue response was less affected than the red response: the mean maximal relative amplitude (M) was 15.8% (SD = 7.8) in patients with DMS compared with 43.0% (SD = 5.5) in normal subjects for red stimulation, and M = 40.8%, SD = 8.4 (DMS) with M = 58.3%, SD = 4.8 (normals) for blue stimulation. The reduction was 63% for red stimulation but only 30% for blue stimulation in patients with DMS. Moreover, there was a preserved postillumination pupil response to blue stimulation in DMS patients. In DMS, the melanopsin-mediated ipRGC pathway appeared relatively preserved.
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chromatic Pupillography in hemianopia patients with homonymous visual field defects
Graefes Archive for Clinical and Experimental Ophthalmology, 2017Co-Authors: Carina Kelbsch, Tobias Peters, Fumiatsu Maeda, Barbara Wilhelm, Torsten Straser, Karolina Skorkovska, Helmut WilhelmAbstract:Purpose The pupil light reflex is considered to be a simple subcortical reflex. However, many studies have proven that patients with isolated occipital lesions with homonymous hemianopia show pupillary hemihypokinesia. Our hypothesis is that the afferent pupillary system consists of two pathways: one via intrinsically photosensitive retinal ganglion cells (ipRGCs), the other running through the normal RGCs via the visual cortex. The purpose of this study was to test the hypothesis of these two separate pupillomotor pathways.
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analysis of retinal function using chromatic Pupillography in retinitis pigmentosa and the relationship to electrically evoked phosphene thresholds
Acta Ophthalmologica, 2017Co-Authors: Carina Kelbsch, Torsten Strasser, Fumiatsu Maeda, Jolanta Lisowska, Lukasz Lisowski, K. Stingl, Barbara WilhelmAbstract:Purpose To analyse pupil responses to specific chromatic stimuli in patients with advanced retinitis pigmentosa (RP) to ascertain whether chromatic Pupillography can be used as an objective marker for residual retinal function. To examine correlations between parameters of the pupil response and the perception threshold of electrically evoked phosphenes. Methods Chromatic Pupillography was performed in 40 patients with advanced RP (visual acuity < 0.02 or visual field ≤5°, non-recordable ERGs) and 40 age-matched healthy subjects. Pupil responses to full-field red (605 nm) and blue (420 nm) stimuli of 28 lx corneal illumination were recorded and analysed for two stimulus durations (1 and 4 seconds). The perception threshold of phosphenes to transcorneal electrostimulation was ascertained and correlated to the pupil responses and visual acuity. Results Patients with RP showed significantly reduced pupil responses to red and blue stimuli compared with the controls. With red stimuli, pupillary escape could be observed; blue stimuli resulted in a well-preserved postillumination pupil response. Phosphene thresholds were significantly increased in patients with RP and correlated with the parameters of the pupil response if all subjects were considered. Within the RP group alone, this relationship was less pronounced and statistically not significant. Conclusions Chromatic Pupillography demonstrated a significant decrease in outer retinal photoreceptor responses but a persisting and disinhibited intrinsic photosensitive retinal ganglion cell function in advanced RP. These phenomena may be useful as an objective marker for the efficacy of any interventional treatment for hereditary retinal diseases as well as for the selection of suitable patients for an electronic retinal implant.
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Analysis of retinal function using chromatic Pupillography in retinitis pigmentosa and the relationship to electrically evoked phosphene thresholds
Acta Ophthalmologica, 2016Co-Authors: Carina Kelbsch, Torsten Strasser, Fumiatsu Maeda, Jolanta Lisowska, Lukasz Lisowski, K. Stingl, Barbara Wilhelm, Helmut Wilhelm, Tobias PetersAbstract:Purpose To analyse pupil responses to specific chromatic stimuli in patients with advanced retinitis pigmentosa (RP) to ascertain whether chromatic Pupillography can be used as an objective marker for residual retinal function. To examine correlations between parameters of the pupil response and the perception threshold of electrically evoked phosphenes. Methods Chromatic Pupillography was performed in 40 patients with advanced RP (visual acuity
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How do spontaneous pupillary oscillations in light relate to light intensity
Vision Research, 2008Co-Authors: Max Warga, Holger Lüdtke, Helmut Wilhelm, Barbara WilhelmAbstract:Characteristics of light-induced pupillary oscillations at constant light intensities have been investigated sparsely compared to sleepiness-related pupillary oscillations in darkness. This study presents the first controlled analysis of light-induced pupillary oscillations and their relationship to illumination. Pupillary oscillations of alert subjects were recorded by infrared video Pupillography in different background lighting. Although showing obvious relationships of mean frequency and amplitude to light intensity, there were considerable inter- and intra-individual differences in the appearance of light-induced oscillations. As they looked rather similar to sleepiness waves, the question remains to identify light-induced oscillations in day light and to differentiate them from sleepiness-related oscillations.
Helmut Wilhelm - One of the best experts on this subject based on the ideXlab platform.
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Color Pupillography in Dorsal Midbrain Syndrome
Journal of Neuro-ophthalmology, 2017Co-Authors: Carina Kelbsch, Torsten Strasser, Tobias Peters, Fumiatsu Maeda, Barbara Wilhelm, Helmut WilhelmAbstract:The purpose of this study was to evaluate the pupil response to chromatic stimuli in patients with lesions in the dorsal midbrain and possibly gain new insights into the afferent pupillary pathways. Color Pupillography was performed in 5 patients with dorsal midbrain syndrome (DMS), and their results were compared with those of 20 healthy control subjects. We used full-field red stimuli (605 nm) that primarily address the rod/cone system and blue stimuli (420 nm) that preferentially activate intrinsically photosensitive retinal ganglion cells (ipRGCs) directly, with a duration of 4 seconds and a stimulus intensity of 28 lx corneal illumination under mesopic conditions. One eye was stimulated, and the consensual pupil response was recorded and analyzed. The pupillary light reflex in patients with DMS was reduced, differed in shape, and showed a prolonged latency time compared to normal subjects. The blue response was less affected than the red response: the mean maximal relative amplitude (M) was 15.8% (SD = 7.8) in patients with DMS compared with 43.0% (SD = 5.5) in normal subjects for red stimulation, and M = 40.8%, SD = 8.4 (DMS) with M = 58.3%, SD = 4.8 (normals) for blue stimulation. The reduction was 63% for red stimulation but only 30% for blue stimulation in patients with DMS. Moreover, there was a preserved postillumination pupil response to blue stimulation in DMS patients. In DMS, the melanopsin-mediated ipRGC pathway appeared relatively preserved.
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chromatic Pupillography in hemianopia patients with homonymous visual field defects
Graefes Archive for Clinical and Experimental Ophthalmology, 2017Co-Authors: Carina Kelbsch, Tobias Peters, Fumiatsu Maeda, Barbara Wilhelm, Torsten Straser, Karolina Skorkovska, Helmut WilhelmAbstract:Purpose The pupil light reflex is considered to be a simple subcortical reflex. However, many studies have proven that patients with isolated occipital lesions with homonymous hemianopia show pupillary hemihypokinesia. Our hypothesis is that the afferent pupillary system consists of two pathways: one via intrinsically photosensitive retinal ganglion cells (ipRGCs), the other running through the normal RGCs via the visual cortex. The purpose of this study was to test the hypothesis of these two separate pupillomotor pathways.
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Analysis of retinal function using chromatic Pupillography in retinitis pigmentosa and the relationship to electrically evoked phosphene thresholds
Acta Ophthalmologica, 2016Co-Authors: Carina Kelbsch, Torsten Strasser, Fumiatsu Maeda, Jolanta Lisowska, Lukasz Lisowski, K. Stingl, Barbara Wilhelm, Helmut Wilhelm, Tobias PetersAbstract:Purpose To analyse pupil responses to specific chromatic stimuli in patients with advanced retinitis pigmentosa (RP) to ascertain whether chromatic Pupillography can be used as an objective marker for residual retinal function. To examine correlations between parameters of the pupil response and the perception threshold of electrically evoked phosphenes. Methods Chromatic Pupillography was performed in 40 patients with advanced RP (visual acuity
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How do spontaneous pupillary oscillations in light relate to light intensity
Vision Research, 2008Co-Authors: Max Warga, Holger Lüdtke, Helmut Wilhelm, Barbara WilhelmAbstract:Characteristics of light-induced pupillary oscillations at constant light intensities have been investigated sparsely compared to sleepiness-related pupillary oscillations in darkness. This study presents the first controlled analysis of light-induced pupillary oscillations and their relationship to illumination. Pupillary oscillations of alert subjects were recorded by infrared video Pupillography in different background lighting. Although showing obvious relationships of mean frequency and amplitude to light intensity, there were considerable inter- and intra-individual differences in the appearance of light-induced oscillations. As they looked rather similar to sleepiness waves, the question remains to identify light-induced oscillations in day light and to differentiate them from sleepiness-related oscillations.
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clinical applications of Pupillography
Journal of Neuro-ophthalmology, 2003Co-Authors: Helmut Wilhelm, Barbara WilhelmAbstract:The development of personal computer-based infrared video instruments has allowed Pupillography to enter the clinical arena. Measuring pupil diameter for refractive surgery, distinguishing Horner syndrome from physiologic anisocoria, quantifying the relative afferent pupillary defect, and plotting visual fields by means of graded pupil constriction to focal light stimuli are recent applications in ophthalmology. Pupillography has also been used to determine sleepiness and autonomic effects of new pharmaceuticals.
Carina Kelbsch - One of the best experts on this subject based on the ideXlab platform.
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standards in Pupillography
Frontiers in Neurology, 2019Co-Authors: Carina Kelbsch, Torsten Strasser, Yanjun Chen, Beatrix Feigl, Paul D Gamlin, Randy H Kardon, Tobias Peters, Kathryn A Roecklein, Stuart R Steinhauer, E SzabadiAbstract:The number of research groups studying the pupil is increasing, as is the number of publications. Consequently, new standards in Pupillography are needed to formalize the methodology including recording conditions, stimulus characteristics, as well as suitable parameters of evaluation. Since the description of intrinsically photosensitive retinal ganglion cells (ipRGCs) there has been an increased interest and broader application of Pupillography in ophthalmology as well as other fields including psychology and chronobiology. Colour Pupillography plays an important role not only in research but also in clinical observational and therapy studies like gene therapy of hereditary retinal degenerations and psychopathology. Stimuli can vary in size, brightness, duration, and wavelength. Stimulus paradigms determine whether rhodopsin-driven rod responses, opsin-driven cone responses, or melanopsin-driven ipRGC responses are primarily elicited. Background illumination, adaptation state, and instruction for the participants will furthermore influence the results. This standard recommends a minimum set of variables to be used for Pupillography and specified in the publication methodologies. Initiated at the 32nd International Pupil Colloquium 2017 in Morges, Switzerland, the aim of this manuscript is to outline standards in Pupillography based on current knowledge and experience of pupil experts in order to achieve greater comparability of pupillographic studies. Such standards will particularly facilitate the proper application of Pupillography by researchers new to the field. First we describe general standards, followed by specific suggestions concerning the demands of different targets of pupil research: the afferent and efferent reflex arc, pharmacology, psychology, sleepiness-related research and animal studies.
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Color Pupillography in Dorsal Midbrain Syndrome
Journal of Neuro-ophthalmology, 2017Co-Authors: Carina Kelbsch, Torsten Strasser, Tobias Peters, Fumiatsu Maeda, Barbara Wilhelm, Helmut WilhelmAbstract:The purpose of this study was to evaluate the pupil response to chromatic stimuli in patients with lesions in the dorsal midbrain and possibly gain new insights into the afferent pupillary pathways. Color Pupillography was performed in 5 patients with dorsal midbrain syndrome (DMS), and their results were compared with those of 20 healthy control subjects. We used full-field red stimuli (605 nm) that primarily address the rod/cone system and blue stimuli (420 nm) that preferentially activate intrinsically photosensitive retinal ganglion cells (ipRGCs) directly, with a duration of 4 seconds and a stimulus intensity of 28 lx corneal illumination under mesopic conditions. One eye was stimulated, and the consensual pupil response was recorded and analyzed. The pupillary light reflex in patients with DMS was reduced, differed in shape, and showed a prolonged latency time compared to normal subjects. The blue response was less affected than the red response: the mean maximal relative amplitude (M) was 15.8% (SD = 7.8) in patients with DMS compared with 43.0% (SD = 5.5) in normal subjects for red stimulation, and M = 40.8%, SD = 8.4 (DMS) with M = 58.3%, SD = 4.8 (normals) for blue stimulation. The reduction was 63% for red stimulation but only 30% for blue stimulation in patients with DMS. Moreover, there was a preserved postillumination pupil response to blue stimulation in DMS patients. In DMS, the melanopsin-mediated ipRGC pathway appeared relatively preserved.
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chromatic Pupillography in hemianopia patients with homonymous visual field defects
Graefes Archive for Clinical and Experimental Ophthalmology, 2017Co-Authors: Carina Kelbsch, Tobias Peters, Fumiatsu Maeda, Barbara Wilhelm, Torsten Straser, Karolina Skorkovska, Helmut WilhelmAbstract:Purpose The pupil light reflex is considered to be a simple subcortical reflex. However, many studies have proven that patients with isolated occipital lesions with homonymous hemianopia show pupillary hemihypokinesia. Our hypothesis is that the afferent pupillary system consists of two pathways: one via intrinsically photosensitive retinal ganglion cells (ipRGCs), the other running through the normal RGCs via the visual cortex. The purpose of this study was to test the hypothesis of these two separate pupillomotor pathways.
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analysis of retinal function using chromatic Pupillography in retinitis pigmentosa and the relationship to electrically evoked phosphene thresholds
Acta Ophthalmologica, 2017Co-Authors: Carina Kelbsch, Torsten Strasser, Fumiatsu Maeda, Jolanta Lisowska, Lukasz Lisowski, K. Stingl, Barbara WilhelmAbstract:Purpose To analyse pupil responses to specific chromatic stimuli in patients with advanced retinitis pigmentosa (RP) to ascertain whether chromatic Pupillography can be used as an objective marker for residual retinal function. To examine correlations between parameters of the pupil response and the perception threshold of electrically evoked phosphenes. Methods Chromatic Pupillography was performed in 40 patients with advanced RP (visual acuity < 0.02 or visual field ≤5°, non-recordable ERGs) and 40 age-matched healthy subjects. Pupil responses to full-field red (605 nm) and blue (420 nm) stimuli of 28 lx corneal illumination were recorded and analysed for two stimulus durations (1 and 4 seconds). The perception threshold of phosphenes to transcorneal electrostimulation was ascertained and correlated to the pupil responses and visual acuity. Results Patients with RP showed significantly reduced pupil responses to red and blue stimuli compared with the controls. With red stimuli, pupillary escape could be observed; blue stimuli resulted in a well-preserved postillumination pupil response. Phosphene thresholds were significantly increased in patients with RP and correlated with the parameters of the pupil response if all subjects were considered. Within the RP group alone, this relationship was less pronounced and statistically not significant. Conclusions Chromatic Pupillography demonstrated a significant decrease in outer retinal photoreceptor responses but a persisting and disinhibited intrinsic photosensitive retinal ganglion cell function in advanced RP. These phenomena may be useful as an objective marker for the efficacy of any interventional treatment for hereditary retinal diseases as well as for the selection of suitable patients for an electronic retinal implant.
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development of a chromatic Pupillography protocol for the first gene therapy trial in patients with cnga3 linked achromatopsia
Investigative Ophthalmology & Visual Science, 2017Co-Authors: Carina Kelbsch, Fumiatsu Maeda, Jolanta Lisowska, Lukasz Lisowski, Paul Richter, Susanne Kohl, Ditta ZoborAbstract:To establish a feasible and sensitive pupillographic protocol to assess outer and inner retinal function for the first gene therapy trial in achromatopsia patients (ACHM) with mutations in CNGA3.Twenty-seven CNGA3-ACHM patients and 22 age-matched control subjects were tested using chromatic Pupillography. Three different protocols were established to assess the pupillary light reflex parameters and to create the final protocol. In the individual protocols, various stimulus parameters (i.e., intensity, duration, wavelength, adaptation states) were applied to evaluate the impact of these stimuli on the pupillary response in untreated ACHM patients.In the light-adapted conditions, CNGA3-ACHM patients showed significantly reduced maximal amplitudes compared with the control group when using a 1-second high intensity (28-lux corneal illumination) blue or red stimulus (P < 0.005). In the dark-adapted conditions, CNGA3-ACHM patients unexpectedly revealed significantly increased maximal amplitudes when stimulating with red (1 second) or blue (4 ms and 1 second) stimuli of low intensity (0.01-lux corneal illumination; P < 0.05). Pupil responses of CNGA3-ACHM patients after high intensity (28 lux) red and blue 1-second stimuli were within the normal range.Chromatic Pupillography demonstrated significant reduced pupil responses to stimuli addressing primarily cone function, an increased sensitivity to rod-favoring stimuli and evidence for disinhibition of intrinsically photosensitive retinal ganglion cells in CNGA3-ACHM patients. A final protocol was established based on these findings. These conclusions may be useful for the objective assessment of efficacy gained by gene therapy or other innovative interventions in this hereditary retinal disorder.
Ted Maddess - One of the best experts on this subject based on the ideXlab platform.
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retinotopic effects of visual attention revealed by dichoptic multifocal Pupillography
Scientific Reports, 2018Co-Authors: A C James, Corinne F Carle, Yanti Rosli, Yiling Ho, Maria Kolic, Emilie Rohan, Ted MaddessAbstract:Multifocal pupillographic objective perimetry (mfPOP) has recently been shown to be able to measure cortical function. Here we assessed 44 regions of the central 60 degrees of the visual fields of each eye concurrently in 7 minutes/test. We examined how foveally- and peripherally-directed attention changed response sensitivity and delay across the 44 visual field locations/eye. Four experiments were completed comparing white, yellow and blue stimulus arrays. Experiments 1 to 4 tested 16, 23, 9 and 6 subjects, 49/54 being unique. Experiment 1, Experiments 2 and 3, and Experiment 4 used three variants of the mfPOP method that provided increasingly improved signal quality. Experiments 1 to 3 examined centrally directed attention, and Experiment 4 compared effects of attention directed to different peripheral targets. Attention reduced the sensitivity of the peripheral locations in Experiment 1, but only for the white stimuli not yellow. Experiment 2 confirmed that result. Experiment 3 showed that blue stimuli behaved like white. Peripheral attention showed increased sensitivity around the attentional targets. The results are discussed in terms of the cortical inputs to the pupillary system. The results agree with those from multifocal and other fMRI and VEP studies. mfPOP may be a useful adjunct to those methods.
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multifocal Pupillography in early age related macular degeneration
Optometry and Vision Science, 2014Co-Authors: Faran Sabeti, Ted Maddess, Rohan W Essex, Aiasha Saikal, A C James, Corinne F CarleAbstract:Purpose. To investigate the potential of multifocal pupillographic objective perimetry to assess changes in retinal function with clinical severity of age-related macular degeneration (AMD). Methods. Pupil responses were recorded from 40 subjects with AMD and 23 normal control subjects (mean T SD age, 71.3 T 5.1 years). Age-related macular degeneration subjects were classified according to the Age-Related Eye Disease Study (AREDS) classification system and allocated into one of four AMD severity groups. Three multifocal pupillographic objective perimetry stimulus variants that were identical in luminance but varied in spatiotemporal sequence were used. In one of the three protocols, stimuli were presented with a pedestal flicker for 266 milliseconds at 15 Hz. Results. On average, response amplitudes demonstrated a significant change in sensitivity with progression from earlystage (0.32 T 0.08 dB, t = 3.88) to late-stage (j1.60 T 0.12 dB, t = j12.7) age-related macular degeneration. Response delays followed a similar trend with the longest delays in AREDS4 (57.2T 1.9 milliseconds, t = 29.5). Ring analysis identified the largest mean effect on responses within the central 6 degrees of fixation. The NewStimuli protocol achieved the best diagnostic accuracy across all severity groups with area under the curve values of 0.85 T 0.066 (AREDS1), 0.908 T 0.085 (AREDS2), 0.929 T 0.040 (AREDS3), and 1.0 T 0.0 (AREDS4). Conclusions. The mean effect of AMD on contraction amplitudes and response delays reflected the severity of disease, and the NewStimuli protocol achieved good diagnostic accuracy across all AMD severity groups. Multifocal pupillographic objective perimetry may potentially be a useful method in monitoring progression of AMD and assessing change in retinal function with novel interventions in early AMD. Longitudinal studies are required to identify biomarkers that predict eyes at risk of progression. (Optom Vis Sci 2014;91:904Y915)
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multifocal Pupillography identifies retinal dysfunction in early age related macular degeneration
Graefes Archive for Clinical and Experimental Ophthalmology, 2013Co-Authors: Faran Sabeti, Rohan W Essex, A C James, Ted MaddessAbstract:Background Early age-related macular degeneration (AMD) is common among the elderly. While only a small number progress to sight-threatening stages of AMD, identifying prognostic functional markers remains paramount. Here, we objectively evaluate retinal function in patients with large drusen by multifocal pupillographic objective perimetry (mfPOP). Different temporal presentation rates and luminances were compared to optimize parameters for high signal to noise ratios (SNR) and diagnosticity for early AMD.
