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Yuan N, Li M, Chen X, Lu Y, Fang Y, Gong H, Qian L, Wu J, Zhang S, Shipp S, Andolina IM, Sun X, Wang W. Immediate Impact of Acute Elevation of Intraocular Pressure on Cortical Visual Motion Processing. Invest Ophthalmol Vis Sci 2020; 61:59. [PMID: 32462199 PMCID: PMC7405714 DOI: 10.1167/iovs.61.5.59] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Purpose To physiologically examine the impairment of cortical sensitivity to visual motion during acute elevation of intraocular pressure (IOP). Methods Motion processing in the cat brain is well characterized, its X and Y cell visual pathways being functionally analogous to parvocellular and magnocellular pathways in primates. Using this model, we performed ocular anterior chamber perfusion to reversibly elevate IOP over a range from 30 to 90 mm Hg while monitoring cortical activity with intrinsic signal optical imaging. Drifting random-dot fields and gratings were used to characterize cortical population responses to motion direction and orientation in early visual areas 17 and 18. Results We found that acute IOP elevations at 50 mm Hg and above, which is often observed in acute glaucoma, suppressed cortical motion direction responses. This suppression was more profound in area 17 than in area 18, and more profound in central than peripheral visual field (eccentricities 0°–4° vs. 4°–8°) within area 17. In addition, orientation responses were more suppressed than motion direction responses for the same IOP modulation. Conclusions In contrast to human chronic glaucoma that may cause greater dysfunction in large-cell magnocellular than in small-cell parvocellular visual pathways, our direct measurement of cortical processing networks implies that the small X-cell pathway shows greater vulnerability to acute IOP elevation than the large Y-cell pathway in visual motion processing. The results demonstrate that fine discrimination mechanisms for motion in the central visual field are particularly impacted by acute IOP attacks, suggesting a neural basis for immediate visual deficits in the fine motion perception of acute glaucoma patients.
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Tarita-Nistor L, Samet S, Trope GE, González EG. Dominance wave propagation during binocular rivalry in mild glaucoma. Vision Res 2019; 165:64-71. [PMID: 31678616 DOI: 10.1016/j.visres.2019.10.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 10/02/2019] [Accepted: 10/09/2019] [Indexed: 12/23/2022]
Abstract
Glaucoma is both a progressive optic neuropathy and a neurodegenerative disease affecting structures in the primary visual pathway. Other vision-associated areas may also be affected, including the corpus callosum which is involved in inter-hemispheric transfer. This study evaluated dominance wave propagation during binocular rivalry to probe the efficacy of the inter-hemispheric transfer in 20 patients with mild open angle glaucoma and 25 age-matched controls. The two groups were matched for functional measures such as stereo-acuity, binocular visual acuity, and visual field mean deviation. Monocular functional and structural measures were equivalent for the left and right eye of each participant. Using Wilson et al.'s travelling wave paradigm [Nature, 412 (2001) 907-910], intra- and inter-hemispheric failure rates of traveling wave transmission and the travelling wave propagation times were recorded for the two groups. For the control group, the wave propagation failure rate was significantly greater for the inter- than for the intra-hemispheric condition, but for the glaucoma group, the failure rates were equally high for the two conditions. The wave propagation time was significantly longer for the inter- than for the intra-hemispheric condition for the control group, while the opposite was true for the glaucoma group. These results reveal changes in the wave dynamics of rivalry dominance in patients with mild glaucoma who otherwise have normal performance on standard functional measures.
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Affiliation(s)
| | - Saba Samet
- Krembil Research Institute, Toronto, Canada; Faculty of Medicine, University of Toronto, Canada
| | - Graham E Trope
- Krembil Research Institute, Toronto, Canada; Ophthalmology and Vision Science, University of Toronto, Canada
| | - Esther G González
- Krembil Research Institute, Toronto, Canada; Ophthalmology and Vision Science, University of Toronto, Canada
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Mias C, Le Digabel J, Filiol J, Gontier E, Gravier E, Villaret A, Nocera T, Questel E, Rossi AB, Redoulès D, Josse G. Visualization of dendritic cells' responses in atopic dermatitis: Preventing effect of emollient. Exp Dermatol 2017; 27:374-377. [PMID: 29178515 DOI: 10.1111/exd.13470] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/20/2017] [Indexed: 11/27/2022]
Abstract
Atopic dermatitis (AD) is a chronic and multifactorial inflammatory skin disease involving various dendritic cells such as epidermal Langerhans cells (LC) and inflammatory dendritic epidermal cells (IDECs). Most of the clinical studies was performed on isolated cells, and thus, it would be useful to characterize directly on the human epidermal tissue the first cellular events occurred during the AD. The suction blister method was used to obtain whole epidermis samples and interstitial cutaneous fluids. Employing multiphoton microscopy, we analyzed the early dynamic behavior of inflammatory cells using Dermatophagoides pteronyssinus atopy patch test (Derp-APT) and evaluated the effects of emollient pre-application. Derp-APT application provoked rapid and strong infiltration of IDECs, and proliferation and activation of LC in the AD subjects' epidermis. Moreover, emollient pre-application strengthened the defective skin barrier and had positive effects on inflammatory cells' behavior, characterized by the complete inhibition of IDEC influx and the presence of immature LC.
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Affiliation(s)
- Céline Mias
- Skin Research Center, Pierre Fabre Dermo-Cosmétique, Toulouse, France
| | - Jimmy Le Digabel
- Skin Research Center, Pierre Fabre Dermo-Cosmétique, Toulouse, France
| | - Jérôme Filiol
- Skin Research Center, Pierre Fabre Dermo-Cosmétique, Toulouse, France
| | - Etienne Gontier
- Bordeaux Imaging Center-UMS 3420 CNRS/Université de Bordeaux-US4 INSERM, Bordeaux, France
| | - Eléonore Gravier
- Skin Research Center, Pierre Fabre Dermo-Cosmétique, Toulouse, France
| | - Aurélie Villaret
- Skin Research Center, Pierre Fabre Dermo-Cosmétique, Toulouse, France
| | - Thérèse Nocera
- Skin Research Center, Pierre Fabre Dermo-Cosmétique, Toulouse, France
| | - Emmanuel Questel
- Skin Research Center, Pierre Fabre Dermo-Cosmétique, Toulouse, France
| | - Ana-Beatris Rossi
- Skin Research Center, Pierre Fabre Dermo-Cosmétique, Toulouse, France
| | - Daniel Redoulès
- Skin Research Center, Pierre Fabre Dermo-Cosmétique, Toulouse, France
| | - Gwendal Josse
- Skin Research Center, Pierre Fabre Dermo-Cosmétique, Toulouse, France
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Abstract
PURPOSE Large moving scenes can induce a sensation of self-motion in stationary observers. This illusion is called "vection." Glaucoma progressively affects the functioning of peripheral vision, which plays an important role in inducing vection. It is still not known whether vection can be induced in these patients and, if it can, whether the interaction between visual and vestibular inputs is solved appropriately. The aim of this study was to investigate vection responses in patients with mild to moderate open-angle glaucoma. METHODS Fifteen patients with mild to moderate glaucoma and 15 age-matched controls were exposed to a random-dot pattern at a short viewing distance and in a dark room. The pattern was projected on a large screen and rotated clockwise with an angular speed of 45 degrees per second to induce a sensation of self-rotation. Vection latency, vection duration, and objective and subjective measures of tilt were obtained in three viewing conditions (binocular, and monocular with each eye). Each condition lasted 2 minutes. RESULTS Patients with glaucoma had longer vection latencies (p = 0.005) than, but the same vection duration as, age-matched controls. Viewing condition did not affect vection responses for either group. The control group estimated the tilt angle as being significantly larger than the actual maximum tilt angle measured with the tilt sensor (p = 0.038). There was no relationship between vection measures and visual field sensitivity for the glaucoma group. CONCLUSIONS These findings suggest that, despite an altered visual input that delays vection, the neural responses involved in canceling the illusion of self-motion remain intact in patients with mild peripheral visual field loss.
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Rauscher FG, Chisholm CM, Edgar DF, Barbur JL. Assessment of novel binocular colour, motion and contrast tests in glaucoma. Cell Tissue Res 2013; 353:297-310. [PMID: 23812834 DOI: 10.1007/s00441-013-1675-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 06/06/2013] [Indexed: 12/29/2022]
Abstract
The effects of glaucoma on binocular visual sensitivity for the detection of various stimulus attributes are investigated at the fovea and in four paracentral retinal regions. The study employed a number of visual stimuli designed to isolate the processing of various stimulus attributes. We measured absolute contrast detection thresholds and functional contrast sensitivity by using Landolt ring stimuli. This psychophysical Landolt C-based contrast test of detection and gap discrimination allowed us to test parafoveally at 6 ° from fixation and foveally by employing interleaved testing locations. First-order motion perception was examined by using moving stimuli embedded in static luminance contrast noise. Red/green (RG) and yellow/blue (YB) colour thresholds were measured with the Colour Assessment and Diagnosis (CAD) test, which utilises random dynamic luminance contrast noise (± 45 %) to ensure that only colour and not luminance signals are available for target detection. Subjects were normal controls (n = 65) and glaucoma patients with binocular visual field defects (n = 15) classified based on their Humphrey Field Analyzer mean deviation (MD) scores. The impairment of visual function varied depending on the stimulus attribute and location tested. Progression of loss was noted for all tests as the degree of glaucoma increased. For subjects with mild glaucoma (MD -0.01 dB to -6.00 dB) significantly more data points fell outside the normal age-representative range for RG colour thresholds than for any other visual test, followed by motion thresholds. This was particularly the case for the parafoveal data compared with the foveal data. Thus, a multifaceted measure of binocular visual performance, incorporating RG colour and motion test at multiple locations, might provide a better index for comparison with quality of life measures in glaucoma.
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Affiliation(s)
- Franziska G Rauscher
- Department of Ophthalmology, Leipzig University Hospital, Liebigstrasse 10-14, 04103, Leipzig, Germany.
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Abstract
Perimetry of some kind remains an important tool in the detection, diagnosis and monitoring of glaucomatous damage to the visual pathway. However, recent studies have served to reinforce the suspicion that conventional perimetry does not possess the sensitivity to detect the earliest signs of functional loss resulting from glaucoma. The relationship between differential light threshold and ganglion cell loss is extremely weak and, in the early stages of glaucoma, non-existent. Alternative, more novel perimetric techniques seem to offer promise of better detectability for early loss by claiming to tap in to one or other of the separate parallel pathways of the visual system. While some of these tests show potential for better detection and monitoring of glaucoma, the reasons why this might be so are not always clearly formulated or represented. This leads to misunderstanding of what the test actually measures and of the glaucomatous disease process itself. This paper seeks to revisit and review the theory underlying psychophysical testing of visual function related to glaucoma and stresses the importance of developing tests that are based on a firm theoretical understanding of visual function and processing in order to both detect glaucoma at an earlier stage and better understand the mechanisms of loss from the disease process.
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Affiliation(s)
- Roger S Anderson
- Vision Science Research Group, School of Biomedical Sciences, University of Ulster at Coleraine, Co. Londonderry, Northern Ireland BT52 1SA, UK.
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Westcott MC, Garway-Heath DF, Fitzke FW, Kamal D, Hitchings RA. Use of high spatial resolution perimetry to identify scotomata not apparent with conventional perimetry in the nasal field of glaucomatous subjects. Br J Ophthalmol 2002; 86:761-6. [PMID: 12084745 PMCID: PMC1771187 DOI: 10.1136/bjo.86.7.761] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIM To examine whether high spatial resolution perimetry (HSRP) could identify fine scale scotomata which may not be apparent with conventional perimetry. The HSRP was performed in the nasal field, as this location is a recognised site for the early occurrence of glaucomatous defects. METHOD 16 early glaucoma eyes, 17 glaucoma suspect eyes, and 20 age matched healthy control eyes underwent conventional automated perimetry using the 24-2 program of the Humphrey field analyser (HFA) and HSRP. The HSRP was performed in the nasal field by testing 9 x 9 degrees of 100 tested points separated by 1 degree and the results compared with the HFA 24-2 program. RESULTS Mean HSRP thresholds were significantly abnormal in the suspect and glaucoma eyes, with elevated levels of asymmetry between the superior and inferior nasal field. Overall, 7/17 (41%) suspect eyes (95% confidence interval 5/17 (29%) to 7/17 (41%)) had nasal scotomata on HSRP, although their HFA 24-2 fields failed to identify any defects. In glaucomatous eyes, 15/16 (94%) eyes had HSRP scotomata (95% CI 14/16 (88%) to 15/16 (94%)). In 12 these coexisted with HFA 24-2 defects at the same location, while in three eyes only HSRP identified scotomata in the nasal field. CONCLUSION HSRP can identify scotoma in glaucomatous eyes in the nasal field which may be missed with the lower spatial resolution of conventional perimetry.
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Affiliation(s)
- M C Westcott
- Glaucoma Unit, Moorfields, Eye Hospital, City Road, London, UK
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Abstract
Advances in our understanding of the pathophysiology of retinal ganglion cell death in glaucoma are providing important insights into the functional changes occurring in retinal ganglion cells in the early stages of the disease. These exciting new findings may help us develop psychophysical tests to monitor early retinal ganglion cell damage, possibly before neurons are committed to the process of cell death.
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Affiliation(s)
- E A Ansari
- Department of Ophthalmology, University Hospital of Wales, Cardiff, UK
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Abstract
More than 50% of ganglion cells may be damaged before visual field loss is measurable by conventional methods in primary open angle glaucoma. There is general agreement on the need to improve early diagnosis of visual field loss in primary open angle glaucoma. In this article, new techniques that enlist measurement of paracentral regions are discussed, and the ability of each method to detect visual field loss prior to perimetric loss is described.
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Affiliation(s)
- I Bodis-Wollner
- State University of New York, Health Science Center at Brooklyn, New York 11203, USA
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