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Visual advantage in deaf adults linked to retinal changes.

Codina C, Pascalis O, Mody C, Toomey P, Rose J, Gummer L, Buckley D - PLoS ONE (2011)

Bottom Line: Deaf adults also showed a significantly different pattern of retinal nerve fibre layer (RNFL) distribution compared to controls.Significant correlations between the depth of the RNFL at the inferior-nasal peripapillary retina and the corresponding far temporal and superior temporal visual field areas (sensitivity) were found.Our results show that cross-modal plasticity after early onset deafness may not be limited to the sensory cortices, noting specific retinal adaptations in early onset deaf adults which are significantly correlated with peripheral vision sensitivity.

View Article: PubMed Central - PubMed

Affiliation: Academic Unit of Ophthalmology and Orthoptics, University of Sheffield, Sheffield, United Kingdom. C.Codina@Sheffield.ac.uk

ABSTRACT
The altered sensory experience of profound early onset deafness provokes sometimes large scale neural reorganisations. In particular, auditory-visual cross-modal plasticity occurs, wherein redundant auditory cortex becomes recruited to vision. However, the effect of human deafness on neural structures involved in visual processing prior to the visual cortex has never been investigated, either in humans or animals. We investigated neural changes at the retina and optic nerve head in profoundly deaf (N = 14) and hearing (N = 15) adults using Optical Coherence Tomography (OCT), an in-vivo light interference method of quantifying retinal micro-structure. We compared retinal changes with behavioural results from the same deaf and hearing adults, measuring sensitivity in the peripheral visual field using Goldmann perimetry. Deaf adults had significantly larger neural rim areas, within the optic nerve head in comparison to hearing controls suggesting greater retinal ganglion cell number. Deaf adults also demonstrated significantly larger visual field areas (indicating greater peripheral sensitivity) than controls. Furthermore, neural rim area was significantly correlated with visual field area in both deaf and hearing adults. Deaf adults also showed a significantly different pattern of retinal nerve fibre layer (RNFL) distribution compared to controls. Significant correlations between the depth of the RNFL at the inferior-nasal peripapillary retina and the corresponding far temporal and superior temporal visual field areas (sensitivity) were found. Our results show that cross-modal plasticity after early onset deafness may not be limited to the sensory cortices, noting specific retinal adaptations in early onset deaf adults which are significantly correlated with peripheral vision sensitivity.

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Circumpapillary RNFL measurements for deaf and hearing participants and corresponding retinal locations.Figure 4a shows the eight locations at which RNFL measurements were taken on the y axis for deaf participants (blue) and hearing participants (red) for the right eye only. Error bars denote SEM. 4b illustrates these circumpapillary locations by highlighting in bold the two retinal locations at which significant differences were found between deaf and hearing participants. Pale yellow overlay denotes temporal hemi-retina relating to the nasal binocular visual field in which areas hearing showed thicker RNFL than deaf; pale blue denotes nasal hemi-retina relating to the temporal monocular visual field in which areas deaf showed thicker RNFL than hearing. The black lines indicate the right eye retinal nerve axonal pathways from the ganglion cells to the optic disc (OD; indicated by the white oval). This image has been adapted and shaded from Hogan MJ, Alvarado JA, Weddell JE (1971) Histology of the Human Eye An Atlas and Textbook, W.B. Saunders Company p536.
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pone-0020417-g004: Circumpapillary RNFL measurements for deaf and hearing participants and corresponding retinal locations.Figure 4a shows the eight locations at which RNFL measurements were taken on the y axis for deaf participants (blue) and hearing participants (red) for the right eye only. Error bars denote SEM. 4b illustrates these circumpapillary locations by highlighting in bold the two retinal locations at which significant differences were found between deaf and hearing participants. Pale yellow overlay denotes temporal hemi-retina relating to the nasal binocular visual field in which areas hearing showed thicker RNFL than deaf; pale blue denotes nasal hemi-retina relating to the temporal monocular visual field in which areas deaf showed thicker RNFL than hearing. The black lines indicate the right eye retinal nerve axonal pathways from the ganglion cells to the optic disc (OD; indicated by the white oval). This image has been adapted and shaded from Hogan MJ, Alvarado JA, Weddell JE (1971) Histology of the Human Eye An Atlas and Textbook, W.B. Saunders Company p536.

Mentions: We further assessed any neural differences at the retina in the deaf by analysing the depth of the retinal nerve fibre layer (RNFL) across 4 cardinal and 4 inter-cardinal areas circumferential to the optic nerve head. Figure 4a shows the 8 areas around the optic nerve head at which RNFL thickness was measured, showing a difference in the RNFL distribution between deaf and hearing participants and Figure 4b shows a schematic representation of the retina, with yellow overlay denoting regions where hearing participants showed thicker RNFL and blue overlay denoting the regions where deaf had thicker RNFL. A two factor mixed measures analysis of variance (ANOVA) was conducted to analyse the data where the first factor was group (deaf or hearing) and the second factor was retinal area (the 8 peripapillary areas at which RNFL thickness was measured) on the 6.8 mm scan (see Experimental Procedures). A separate ANOVA was conducted for data from the 2.9 mm scan, but significant differences were found only at 6.8 mm, where RCGs are further towards destination retinal locations (see Figure 4b). For the 6.8 mm scan there was no significant effect of hearing status on overall RNFL thickness (p = 0.334). However, significant interaction was found between hearing status and retinal location (F7,210 = 2.282, p = 0.021). Post-hoc t-tests corrected for multiple analyses by Bonferroni adjustment were conducted between deaf and hearing participants at each retinal location. In Figure 4b the bold yellow illustrates the peripapillary region at which RNFL was significantly thicker for hearing participants (t = 2.48, p = 0.04). This region is immediately temporal to the optic nerve head and contains the papillomacular bundle. The bold blue colouring marks the inferior nasal peripapillary region wherein RNFL was significantly thicker for deaf participants (t = 2.713, p = 0.041). Interestingly, this region serves the far monocular temporal visual field.


Visual advantage in deaf adults linked to retinal changes.

Codina C, Pascalis O, Mody C, Toomey P, Rose J, Gummer L, Buckley D - PLoS ONE (2011)

Circumpapillary RNFL measurements for deaf and hearing participants and corresponding retinal locations.Figure 4a shows the eight locations at which RNFL measurements were taken on the y axis for deaf participants (blue) and hearing participants (red) for the right eye only. Error bars denote SEM. 4b illustrates these circumpapillary locations by highlighting in bold the two retinal locations at which significant differences were found between deaf and hearing participants. Pale yellow overlay denotes temporal hemi-retina relating to the nasal binocular visual field in which areas hearing showed thicker RNFL than deaf; pale blue denotes nasal hemi-retina relating to the temporal monocular visual field in which areas deaf showed thicker RNFL than hearing. The black lines indicate the right eye retinal nerve axonal pathways from the ganglion cells to the optic disc (OD; indicated by the white oval). This image has been adapted and shaded from Hogan MJ, Alvarado JA, Weddell JE (1971) Histology of the Human Eye An Atlas and Textbook, W.B. Saunders Company p536.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3105994&req=5

pone-0020417-g004: Circumpapillary RNFL measurements for deaf and hearing participants and corresponding retinal locations.Figure 4a shows the eight locations at which RNFL measurements were taken on the y axis for deaf participants (blue) and hearing participants (red) for the right eye only. Error bars denote SEM. 4b illustrates these circumpapillary locations by highlighting in bold the two retinal locations at which significant differences were found between deaf and hearing participants. Pale yellow overlay denotes temporal hemi-retina relating to the nasal binocular visual field in which areas hearing showed thicker RNFL than deaf; pale blue denotes nasal hemi-retina relating to the temporal monocular visual field in which areas deaf showed thicker RNFL than hearing. The black lines indicate the right eye retinal nerve axonal pathways from the ganglion cells to the optic disc (OD; indicated by the white oval). This image has been adapted and shaded from Hogan MJ, Alvarado JA, Weddell JE (1971) Histology of the Human Eye An Atlas and Textbook, W.B. Saunders Company p536.
Mentions: We further assessed any neural differences at the retina in the deaf by analysing the depth of the retinal nerve fibre layer (RNFL) across 4 cardinal and 4 inter-cardinal areas circumferential to the optic nerve head. Figure 4a shows the 8 areas around the optic nerve head at which RNFL thickness was measured, showing a difference in the RNFL distribution between deaf and hearing participants and Figure 4b shows a schematic representation of the retina, with yellow overlay denoting regions where hearing participants showed thicker RNFL and blue overlay denoting the regions where deaf had thicker RNFL. A two factor mixed measures analysis of variance (ANOVA) was conducted to analyse the data where the first factor was group (deaf or hearing) and the second factor was retinal area (the 8 peripapillary areas at which RNFL thickness was measured) on the 6.8 mm scan (see Experimental Procedures). A separate ANOVA was conducted for data from the 2.9 mm scan, but significant differences were found only at 6.8 mm, where RCGs are further towards destination retinal locations (see Figure 4b). For the 6.8 mm scan there was no significant effect of hearing status on overall RNFL thickness (p = 0.334). However, significant interaction was found between hearing status and retinal location (F7,210 = 2.282, p = 0.021). Post-hoc t-tests corrected for multiple analyses by Bonferroni adjustment were conducted between deaf and hearing participants at each retinal location. In Figure 4b the bold yellow illustrates the peripapillary region at which RNFL was significantly thicker for hearing participants (t = 2.48, p = 0.04). This region is immediately temporal to the optic nerve head and contains the papillomacular bundle. The bold blue colouring marks the inferior nasal peripapillary region wherein RNFL was significantly thicker for deaf participants (t = 2.713, p = 0.041). Interestingly, this region serves the far monocular temporal visual field.

Bottom Line: Deaf adults also showed a significantly different pattern of retinal nerve fibre layer (RNFL) distribution compared to controls.Significant correlations between the depth of the RNFL at the inferior-nasal peripapillary retina and the corresponding far temporal and superior temporal visual field areas (sensitivity) were found.Our results show that cross-modal plasticity after early onset deafness may not be limited to the sensory cortices, noting specific retinal adaptations in early onset deaf adults which are significantly correlated with peripheral vision sensitivity.

View Article: PubMed Central - PubMed

Affiliation: Academic Unit of Ophthalmology and Orthoptics, University of Sheffield, Sheffield, United Kingdom. C.Codina@Sheffield.ac.uk

ABSTRACT
The altered sensory experience of profound early onset deafness provokes sometimes large scale neural reorganisations. In particular, auditory-visual cross-modal plasticity occurs, wherein redundant auditory cortex becomes recruited to vision. However, the effect of human deafness on neural structures involved in visual processing prior to the visual cortex has never been investigated, either in humans or animals. We investigated neural changes at the retina and optic nerve head in profoundly deaf (N = 14) and hearing (N = 15) adults using Optical Coherence Tomography (OCT), an in-vivo light interference method of quantifying retinal micro-structure. We compared retinal changes with behavioural results from the same deaf and hearing adults, measuring sensitivity in the peripheral visual field using Goldmann perimetry. Deaf adults had significantly larger neural rim areas, within the optic nerve head in comparison to hearing controls suggesting greater retinal ganglion cell number. Deaf adults also demonstrated significantly larger visual field areas (indicating greater peripheral sensitivity) than controls. Furthermore, neural rim area was significantly correlated with visual field area in both deaf and hearing adults. Deaf adults also showed a significantly different pattern of retinal nerve fibre layer (RNFL) distribution compared to controls. Significant correlations between the depth of the RNFL at the inferior-nasal peripapillary retina and the corresponding far temporal and superior temporal visual field areas (sensitivity) were found. Our results show that cross-modal plasticity after early onset deafness may not be limited to the sensory cortices, noting specific retinal adaptations in early onset deaf adults which are significantly correlated with peripheral vision sensitivity.

Show MeSH
Related in: MedlinePlus