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The effect of age on the area of complete spatial summation for chromatic and achromatic stimuli.

Biomedical Sciences Research Institute Computer Science Research Institute Environmental Sciences Research Institute Nanotechnology & Advanced Materials Research Institute

Redmond, T, Zlatkova, MB, Garway-Heath , DF and Anderson, Roger (2010) The effect of age on the area of complete spatial summation for chromatic and achromatic stimuli. Investigative Ophthalmology and Visual Science, 51 . pp. 6533-6539. [Journal article]

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DOI: 10.1167/iovs.10-5717.

Abstract

PURPOSE: Previously, an association between the area of complete spatial summation (Ricco's area) and age under scotopic conditions had been found. The authors sought to determine whether Ricco's area is similarly associated with age under photopic achromatic and selective S-cone conditions in peripheral vision and whether any association relates to a loss of ganglion cell density as determined by measurements of peripheral grating resolution acuity.METHODS: Achromatic spatial summation functions were plotted for 68 healthy subjects (aged 20-77 years) in four oblique meridians on a gray background field of 10 cd/m(2). Similar functions were generated for the S-cone pathway (isolated using Stiles' two-color threshold method) for the same locations. Ricco's area was determined using two-phase regression analysis. Achromatic peripheral grating resolution acuity was measured at the same locations using high-contrast Gabor stimuli, as an estimate of localized functional ganglion cell density.RESULTS: There was a notable decrease in overall contrast sensitivity with age for all stimulus sizes. However, there was no evidence of age-related change in Ricco's area for either achromatic (superior field, r(2) = 0.05; inferior field, r(2) = 0.0007; all P > 0.05) or chromatic (superior field, r(2) = 0.01; inferior field, r(2) = 0.006; all P > 0.05) stimuli, despite a significant decrease in peripheral grating resolution acuity with age (superior field, r(2) = 0.15; inferior field, r(2) = 0.17; both P < 0.05).CONCLUSIONS: An age-related decline in functional ganglion cell density is not accompanied by a significant change in Ricco's area for achromatic or chromatic stimuli.

Item Type:Journal article
Keywords:ageing, spatial summation, Ricco's area
Faculties and Schools:Faculty of Life and Health Sciences
Faculty of Life and Health Sciences > School of Biomedical Sciences
Research Institutes and Groups:Biomedical Sciences Research Institute
Biomedical Sciences Research Institute > Vision
ID Code:21249
Deposited By:Dr Margarita Vidinova
Deposited On:05 Mar 2012 11:37
Last Modified:05 Mar 2012 11:37

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