The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform
Edoardo Midena - One of the best experts on this subject based on the ideXlab platform.
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retinal function in patients with serpiginous choroiditis a microperimetry study
Graefes Archive for Clinical and Experimental Ophthalmology, 2010Co-Authors: Elisabetta Pilotto, Enrica Convento, Stela Vujosevic, Vuga Ana Grgic, Patrik Sportiello, Antonio G Secchi, Edoardo MidenaAbstract:To investigate Fixation Pattern and retinal sensitivity in patients with serpiginous choroiditis (SC). Twenty-eight eyes (14 patients) with SC were evaluated. Best-corrected visual acuity, color fundus photography, fundus autofluorescence, and fluorescein and indocyanine green angiography were performed. Microperimetry was used to assess Fixation Pattern and retinal sensitivity. Of 28 eyes, 16 (57%) had central, one (4%) poor central, and 11 (39%) eccentric Fixation; and 18 (64%) had stable, four (14%) relatively unstable, and six (21%) unstable Fixation. In patients with posterior pole symmetrically involved in both eyes, the better eye had stable and central Fixation in all cases. Atrophic lesions were characterized by a dense scotoma in all cases, with a relative scotoma at their margins in ten eyes (38%). In two cases of active disease, a dense scotoma correlated to an active lesion could be detected. A relative scotoma was documented in areas not involved by the disease at the posterior pole in eight eyes (28%), and in the peripapillary area in 11 eyes (39%). Quantification of retinal sensitivity and Fixation Pattern by microperimetry offers new data about the impact of visual impairment in patients with SC. A reduction of retinal sensitivity in an apparently healthy area suggests a wider functional involvement of the retina, undetectable by morphologic evaluation alone.
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Fixation Pattern and macular sensitivity in eyes with subfoveal choroidal neovascularization secondary to age related macular degeneration a microperimetry study
Seminars in Ophthalmology, 2004Co-Authors: Edoardo Midena, Pietro Paolo Radin, Elisabetta Pilotto, A Ghirlando, Enrica Convento, Monica VaranoAbstract:Purpose. To investigate the effects of subfoveal choroidal neovascularizzation (CNV) secondary to age-related macular degeneration (AMD) on macular functional parameters quantified with an automatic fundus perimeter. Methods. 118 eyes of 98 consecutive patients with subfoveal CNV secondary to AMD were evaluated. Best corrected visual acuity (ETDRS charts), fundus photography, and fluorescein angiography were performed. Microperimetry (fundus-related perimetry) was used to quantify macular sensitivity and Fixation Pattern (location and stability). Results. Of 118 eyes: 26 (21.9%) had central, 18 (15.1%) poor central and 74 (63.0%) eccentric Fixation; 31 (26.0%) had stable, 42 (35.6%) relatively unstable and 45 (38.4%) unstable Fixation. In 75 eyes (63.4%) a dense central scotoma was found. Angiographic classification of subfoveal CNV (occult versus classic) was not significantly related to Fixation Pattern (location: P = 0.274; stability: P = 0.385), and presence of dense scotoma (P = 0.41). Conclusion. Mi...
Robert E. Wolf - One of the best experts on this subject based on the ideXlab platform.
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abnormal visual function outside the area of atrophy defined by short wavelength fundus autofluorescence in stargardt disease
Investigative Ophthalmology & Visual Science, 2020Co-Authors: Carol A. Applegate, Abraham Ifrah, Janet S. Sunness, Robert E. Wolf, Janet R SparrowAbstract:Purpose: To examine the extent of visual function abnormality outside the dark lesion on short-wavelength fundus autofluorescence (SW-AF), and its correlation with background SW-AF features and optical coherence tomography (OCT) in recessive Stargardt disease (STGD1). Methods: Forty-nine eyes of 25 participants in the ProgStar (the Natural History of the Progression of Atrophy Secondary to Stargardt Disease) study at our center were included. Patients underwent microperimetry (both threshold and dense scotoma mapping), OCT, SW-AF, and visual acuity testing. The Fisher's exact test, the χ2 test, and unpaired t-tests were used to analyze the data. Results: Of 40 eyes without central Fixation, 33 (82%) placed Fixation remote (most ≥5°) from the dense scotoma edge, despite good intervening retinal sensitivity. OCT findings accounted for the remote Fixation in 75%. Eighteen (37%) of all 49 eyes had dense scotoma extending past the dark lesion border. OCT was not adequate to define the edge of the scotoma. Of the 49 eyes, 28 (57%) had the mottled background Pattern, 10 (20%) had the uniform Pattern, and 11 (22%) had the other Pattern, with >75% of eyes in each Pattern having remote Fixation. The dense scotoma exceeded the dark lesion primarily in the mottled Pattern. The two eyes of each patient were concordant in all features. Conclusions: Functional abnormalities in STGD1 extend past the SW-AF dark lesion. The disruption of the ellipsoid zone shows that photoreceptor abnormality extends peripheral to the dark lesion, and it explains in part the remote Fixation Pattern and the dense scotoma exceeding the dark lesion. This has implications for clinical trials for STGD1.
Janet S. Sunness - One of the best experts on this subject based on the ideXlab platform.
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abnormal visual function outside the area of atrophy defined by short wavelength fundus autofluorescence in stargardt disease
Investigative Ophthalmology & Visual Science, 2020Co-Authors: Carol A. Applegate, Abraham Ifrah, Janet S. Sunness, Robert E. Wolf, Janet R SparrowAbstract:Purpose: To examine the extent of visual function abnormality outside the dark lesion on short-wavelength fundus autofluorescence (SW-AF), and its correlation with background SW-AF features and optical coherence tomography (OCT) in recessive Stargardt disease (STGD1). Methods: Forty-nine eyes of 25 participants in the ProgStar (the Natural History of the Progression of Atrophy Secondary to Stargardt Disease) study at our center were included. Patients underwent microperimetry (both threshold and dense scotoma mapping), OCT, SW-AF, and visual acuity testing. The Fisher's exact test, the χ2 test, and unpaired t-tests were used to analyze the data. Results: Of 40 eyes without central Fixation, 33 (82%) placed Fixation remote (most ≥5°) from the dense scotoma edge, despite good intervening retinal sensitivity. OCT findings accounted for the remote Fixation in 75%. Eighteen (37%) of all 49 eyes had dense scotoma extending past the dark lesion border. OCT was not adequate to define the edge of the scotoma. Of the 49 eyes, 28 (57%) had the mottled background Pattern, 10 (20%) had the uniform Pattern, and 11 (22%) had the other Pattern, with >75% of eyes in each Pattern having remote Fixation. The dense scotoma exceeded the dark lesion primarily in the mottled Pattern. The two eyes of each patient were concordant in all features. Conclusions: Functional abnormalities in STGD1 extend past the SW-AF dark lesion. The disruption of the ellipsoid zone shows that photoreceptor abnormality extends peripheral to the dark lesion, and it explains in part the remote Fixation Pattern and the dense scotoma exceeding the dark lesion. This has implications for clinical trials for STGD1.
Selim Onat - One of the best experts on this subject based on the ideXlab platform.
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Fixation Pattern similarity analysis reveals adaptive changes in face viewing strategies following aversive learning
eLife, 2019Co-Authors: Lea Kampermann, Niklas Wilming, Arjen Alink, Christian Buchel, Selim OnatAbstract:Animals can effortlessly adapt their behavior by generalizing from past aversive experiences, allowing to avoid harm in novel situations. We studied how visual information was sampled by eye-movements during this process called fear generalization, using faces organized along a circular two-dimensional perceptual continuum. During learning, one face was conditioned to predict a harmful event, whereas the most dissimilar face stayed neutral. This introduced an adversity gradient along one specific dimension, while the other, unspecific dimension was defined solely by perceptual similarity. Aversive learning changed scanning Patterns selectively along the adversity-related dimension, but not the orthogonal dimension. This effect was mainly located within the eye region of faces. Our results provide evidence for adaptive changes in viewing strategies of faces following aversive learning. This is compatible with the view that these changes serve to sample information in a way that allows discriminating between safe and adverse for a better threat prediction.
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fear generalization as threat prediction adaptive changes in facial exploration strategies revealed by Fixation Pattern similarity analysis
bioRxiv, 2018Co-Authors: Lea Kampermann, Niklas Wilming, Arjen Alink, Christian Buechel, Selim OnatAbstract:Abstract Animals can effortlessly adapt their behavior by generalizing from past experiences, and avoid harm in novel aversive situations. In our current understanding, the perceptual similarity between learning and generalization samples is viewed as one major factor driving aversive generalization. Alternatively, the threat-prediction account proposes that perceptual similarity should lead to generalization to the extent it predicts harmful outcomes. We tested these views using a two-dimensional perceptual continuum of faces. During learning, one face is conditioned to predict a harmful event, whereas the most dissimilar face stays neutral; introducing an adversity gradient defined only along one dimension. Learning changed the way how humans sampled information during viewing of faces. These occurred specifically along the adversity gradient leading to an increased dissimilarity of eye-movement Patterns along the threat-related dimension. This provides evidence for the threat-prediction account of generalization, which conceives perceptual factors to be relevant to the extent they predict harmful outcomes.
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aversive learning changes face viewing strategies as revealed by model based Fixation Pattern similarity analysis
bioRxiv, 2017Co-Authors: Lea Kampermann, Niklas Wilming, Arjen Alink, Christian Buechel, Selim OnatAbstract:To avoid costly situations animals must be able to rapidly predict imminent threat based on past experience and present noisy sensory evidence. We aimed to characterize to what extent active exploration strategies, can be adaptively tuned to achieve this goal. We measured how eye-movement Patterns on 8 faces, organized along a circular similarity continuum, were modified after aversive learning and generalization. Using model-based Fixation Similarity Analysis, we characterized how similarity relationships between exploration strategies were modified after volunteers learnt to pair one face (CS+) with a mild electric shock. Initially, viewing Patterns reflected the circular physical similarity structure of different faces, indicating that eye-movements were guided by subtle differences between faces. Following aversive learning, the similarity structure of exploration Patterns became elliptical and stretched along the adversity gradient defined by the CS+ and the most dissimilar neutral face (CS-), indicating that exploration Patterns on these faces were most dissimilar. These findings suggest that the need to predict adversity introduces substantial remodelling of exploration Patterns and influences entire sensorimotor loops by selecting Fixation locations that can help in categorizing stimuli as aversive or safe.
Elisabetta Pilotto - One of the best experts on this subject based on the ideXlab platform.
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retinal function in patients with serpiginous choroiditis a microperimetry study
Graefes Archive for Clinical and Experimental Ophthalmology, 2010Co-Authors: Elisabetta Pilotto, Enrica Convento, Stela Vujosevic, Vuga Ana Grgic, Patrik Sportiello, Antonio G Secchi, Edoardo MidenaAbstract:To investigate Fixation Pattern and retinal sensitivity in patients with serpiginous choroiditis (SC). Twenty-eight eyes (14 patients) with SC were evaluated. Best-corrected visual acuity, color fundus photography, fundus autofluorescence, and fluorescein and indocyanine green angiography were performed. Microperimetry was used to assess Fixation Pattern and retinal sensitivity. Of 28 eyes, 16 (57%) had central, one (4%) poor central, and 11 (39%) eccentric Fixation; and 18 (64%) had stable, four (14%) relatively unstable, and six (21%) unstable Fixation. In patients with posterior pole symmetrically involved in both eyes, the better eye had stable and central Fixation in all cases. Atrophic lesions were characterized by a dense scotoma in all cases, with a relative scotoma at their margins in ten eyes (38%). In two cases of active disease, a dense scotoma correlated to an active lesion could be detected. A relative scotoma was documented in areas not involved by the disease at the posterior pole in eight eyes (28%), and in the peripapillary area in 11 eyes (39%). Quantification of retinal sensitivity and Fixation Pattern by microperimetry offers new data about the impact of visual impairment in patients with SC. A reduction of retinal sensitivity in an apparently healthy area suggests a wider functional involvement of the retina, undetectable by morphologic evaluation alone.
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Fixation Pattern and macular sensitivity in eyes with subfoveal choroidal neovascularization secondary to age related macular degeneration a microperimetry study
Seminars in Ophthalmology, 2004Co-Authors: Edoardo Midena, Pietro Paolo Radin, Elisabetta Pilotto, A Ghirlando, Enrica Convento, Monica VaranoAbstract:Purpose. To investigate the effects of subfoveal choroidal neovascularizzation (CNV) secondary to age-related macular degeneration (AMD) on macular functional parameters quantified with an automatic fundus perimeter. Methods. 118 eyes of 98 consecutive patients with subfoveal CNV secondary to AMD were evaluated. Best corrected visual acuity (ETDRS charts), fundus photography, and fluorescein angiography were performed. Microperimetry (fundus-related perimetry) was used to quantify macular sensitivity and Fixation Pattern (location and stability). Results. Of 118 eyes: 26 (21.9%) had central, 18 (15.1%) poor central and 74 (63.0%) eccentric Fixation; 31 (26.0%) had stable, 42 (35.6%) relatively unstable and 45 (38.4%) unstable Fixation. In 75 eyes (63.4%) a dense central scotoma was found. Angiographic classification of subfoveal CNV (occult versus classic) was not significantly related to Fixation Pattern (location: P = 0.274; stability: P = 0.385), and presence of dense scotoma (P = 0.41). Conclusion. Mi...