Objective Visual Assessment of Antiangiogenic Treatment for Wet Age-Related Macular Degeneration

Baseler, Heidi A.; Gouws, André; Crossland, Michael D.; Leung, Carmen; Tufail, Adnan; Rubin, Gary S.; Morland, Antony B.

doi:10.1097/opx.0b013e3182282f13

Cited by 18 publications

(19 citation statements)

References 23 publications

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“…Regarding central visual loss, many authors have found unresponsive cortical zones representing the damaged central retina in macular degeneration (Baseler et al, 2011a, Baseler et al, 2011b, Lešták et al, 2013, Liu et al, 2010, Masuda et al, 2008, Sunness et al, 2004). Cortical regions representing the uninjured peripheral visual field may be insufficient to trigger activation in a large number of deprived neurons since central vision is represented in a larger extent of V1.…”

Section: Discussionmentioning

confidence: 99%

“…However, other authors (Baker et al, 2008, Dilks et al, 2009, Schumacher et al, 2008) found cortical reorganization in macular degeneration when stimulating the peripheral retina. Reduced numbers of participants (Baseler et al, 2011a, Sunness et al, 2004), different levels of foveal vision (Baseler et al, 2011a, Lešták et al, 2013, Masuda et al, 2008, Schumacher et al, 2008, Sunness et al, 2004), distinct disease mechanisms - juvenile and age-related macular degeneration (Baseler et al, 2011b, Liu et al, 2010, Schumacher et al, 2008), age differences between studied groups (Crossland et al, 2008, D'Esposito et al, 2003, Lešták et al, 2013, Masuda et al, 2008), and the use of complex stimuli involving higher level areas (Liu et al, 2010) may also contribute to the controversy arising from the interpretation of results from macular degeneration studies (Baseler et al, 2009, Martins Rosa et al, 2013). …”

Section: Discussionmentioning

confidence: 99%

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Primary visual cortical remapping in patients with inherited peripheral retinal degeneration

Ferreira

Pereira

Quendera

et al. 2017

NeuroImage: Clinical

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Human studies addressing the long-term effects of peripheral retinal degeneration on visual cortical function and structure are scarce. Here we investigated this question in patients with Retinitis Pigmentosa (RP), a genetic condition leading to peripheral visual degeneration. We acquired functional and anatomical magnetic resonance data from thirteen patients with different levels of visual loss and twenty-two healthy participants to study primary (V1) visual cortical retinotopic remapping and cortical thickness. We identified systematic visual field remapping in the absence of structural changes in the primary visual cortex of RP patients. Remapping consisted in a retinotopic eccentricity shift of central retinal inputs to more peripheral locations in V1. Importantly, this was associated with changes in visual experience, as assessed by the extent of the visual loss, with more constricted visual fields resulting in larger remapping. This pattern of remapping is consistent with expansion or shifting of neuronal receptive fields into the cortical regions with reduced retinal input. These data provide evidence for functional changes in V1 that are dependent on the magnitude of peripheral visual loss in RP, which may be explained by rapid cortical adaptation mechanisms or long-term cortical reorganization. This study highlights the importance of analyzing the retinal determinants of brain functional and structural alterations for future visual restoration approaches.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Primary visual cortical remapping in patients with inherited peripheral retinal degeneration

Ferreira

Pereira

Quendera

et al. 2017

NeuroImage: Clinical

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“…Baseler et al 7 examined one patient with wet AMD before and after application of three injections of ranibizumab using fMRI. They used full-field flickering (6 Hz) white light alternating with a uniform grey background (18 seconds on and 18 seconds off) as visual stimulation during fMRI examination.…”

Section: Discussionmentioning

confidence: 99%

Functional Magnetic Resonance Imaging in Patients with the Wet Form of Age-Related Macular Degeneration

Lešták¹,

Tintěra²,

Karel³

et al. 2013

Neuro-Ophthalmology

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The study is designed to determine the relationship between the progress of the wet form of age-related macular degeneration and the activity of the visual cortex examined using functional magnetic resonance imaging. Ten patients with the wet form of age-related macular degeneration (9 female and 1 male) with a mean age of 74.7 years (58-85 years) at various stages of bilateral involvement of the disease were included. Patients did not suffer from any other ocular nor neurological disease. All the patients underwent functional magnetic resonance imaging examinations with stimulation of both eyes using a black-and-white checkerboard of size 25.8 Â 16.2 degrees. The group was compared with a group of healthy subjects with an average age of 54.1 years (45-65 years). For statistical evaluation, the Mann-Whitney U test was used. Comparing the extent of visual cortex activations we found a statistically significant difference between both the groups (p = 0.0247). However, the dependence of functional magnetic resonance imaging activity on visual acuity was not statistically significant (p = 0.223). We conclude that in patients with the wet form of age-related macular degeneration, lower functional magnetic resonance imaging activity of the visual cortex was found compared with the control group of healthy subjects. Dependence of functional magnetic resonance imaging activity on visual acuity was not statistically significant.

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“…These parameters include: (1) absolute activated voxel number within specific regions of interest (ROIs) [30][31][32] ; (2) location of activated voxels [30][31][32] ; (3) the statistical significance or contrast intensity of activated voxels 33 ; and (4) proportion of the activated voxel within different ROIs. [34][35][36][37][38][39] Proportion of the activated voxels within specific ROIs is considered to be a reliable index, 40 for the sources of variability affect the whole brain in a similar fashion. 41 Prior research with patients affected by stroke 42 and patients with schizophrenia 43 has shown greater variability in fMRI data for patients than for control subjects.…”

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confidence: 99%

Reproducibility of Activation Maps for Longitudinal Studies of Visual Function by Functional Magnetic Resonance Imaging

Ming

Thulborn

Szlyk

2012

Invest. Ophthalmol. Vis. Sci.

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PURPOSE.To test the intra-and intersubject reproducibility of brain activation patterns that underlie visually guided saccades and word recognition in normally sighted subjects and patients with macular degeneration using functional magnetic resonance imaging (fMRI). METHODS.Ten normally sighted subjects and five patients with macular degeneration were asked to perform two visually guided saccade tasks and two word-recognition tasks during fMRI with behavioral monitoring. The fMRI measurements were repeated three times at intervals of at least 4 weeks between sessions. The intrasubject reproducibility of the brain activation patterns was examined in a model-independent manner by comparing the distributions of activation across the frontal, parietal, temporal, and occipital brain lobes using Intraclass Correlation Coefficients (ICCs). Intersubject reproducibility was examined by repeated-measure ANOVA.RESULTS. Control subjects showed overall higher intrasubject reproducibility of brain activation patterns (75% ICCs > 0.5) than that of patients with macular degeneration (56% ICCs > 0.5). The intrasubject reproducibility for the patients improved when the target location was fixed, as in the word-recognition tasks (75% ICCs > 0.5), compared with the visually saccade tasks (37% ICCs > 0.5). Intersubject variability of brain activation patterns was strikingly high for both the control and patient groups.CONCLUSIONS. The fMRI method can serve as a reliable withinsubjects measure of brain activation that has potential for measuring longitudinal changes in brain networks associated with rehabilitation training. Striking intersubject variability reflected at the level of lobes of the brain among control subjects with similar behavioral performance, suggests individual analysis is necessary when implementing longitudinal brain activation studies. (Invest Ophthalmol Vis Sci.

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Objective Visual Assessment of Antiangiogenic Treatment for Wet Age-Related Macular Degeneration

Cited by 18 publications

References 23 publications

Primary visual cortical remapping in patients with inherited peripheral retinal degeneration

Primary visual cortical remapping in patients with inherited peripheral retinal degeneration

Functional Magnetic Resonance Imaging in Patients with the Wet Form of Age-Related Macular Degeneration

Reproducibility of Activation Maps for Longitudinal Studies of Visual Function by Functional Magnetic Resonance Imaging

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