Adaptation mechanisms, eccentricity profiles, and clinical implementation of red-on-white perimetry.
Optom Vis Sci
; 85(5): 309-17, 2008 May.
Article
em En
| MEDLINE
| ID: mdl-18451735
PURPOSE: To determine the visual adaptation and retinal eccentricity profiles for red flickering and static test stimuli and report a clinical implementation of these stimuli in visual perimetry. METHODS: The adaptation profile for red-on-white perimetry stimuli was measured using a threshold vs. intensity (TvI) paradigm at 0 degree and 12 degrees eccentricity and by comparing the eccentricity-related sensitivity change for red and white, static, and flickering targets in young normal trichromats (n = 5) and a group of dichromats (n = 5). A group of older normal control observers (n = 30) were tested and retinal disease was evaluated in persons having age-related maculopathy (n = 35) and diabetes (n = 12). RESULTS: Adaptation and eccentricity profiles indicate red static and flickering targets are detected by two mechanisms in the paramacular region, and a single mechanism for >5 degrees eccentricity. The group data for the older normal observers has a high level of inter-observer variability with a generalized reduction in sensitivity across the entire visual field. Group data for the participants with age-related maculopathy show reduced sensitivities that were pronounced in the central retina. The group data for the diabetic observers showed sensitivities that were reduced at all eccentricities. The disease-related sensitivity decline was more apparent with red than white stimuli. CONCLUSIONS: The adaptation profile and change in sensitivity with retinal eccentricity for the red-on-white perimetric stimuli are consistent with two detection processes. In the macula, the putative detection mechanism is color-opponent with static targets and non-opponent with flickering targets. At peripheral field locations, the putative detection mechanism is non-opponent for both static and flicker targets. The long-wavelength stimuli are less affected by the preretinal absorption common to aging. Red-on-white static and flicker perimetry may be useful for monitoring retinal disease, revealing greater abnormalities compared with conventional white-on-white perimetry, especially in the macula where two detection mechanisms are found.
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Base de dados:
MEDLINE
Assunto principal:
Retina
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Percepção Visual
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Campos Visuais
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Percepção de Cores
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Testes de Campo Visual
Tipo de estudo:
Etiology_studies
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Incidence_studies
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Observational_studies
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Risk_factors_studies
Limite:
Adolescent
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Adult
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Aged
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Humans
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Middle aged
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article