Regional Extent of Peripheral Suppression in Amblyopia
| Autor: | Simon Clavagnier, William R. Bobier, Raiju J. Babu, Benjamin Thompson, Robert F. Hess |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Adult
Male medicine.medical_specialty genetic structures Visual Acuity Concentric Stimulus (physiology) Amblyopia Anisometropia Contrast Sensitivity 03 medical and health sciences 0302 clinical medicine Ophthalmology medicine Humans In patient Strabismus Vision Binocular business.industry medicine.disease eye diseases Visual field Peripheral Sensory Thresholds 030221 ophthalmology & optometry Optometry Female Visual angle Visual Fields business 030217 neurology & neurosurgery Photic Stimulation |
| Zdroj: | Investigative ophthalmologyvisual science. 58(4) |
| ISSN: | 1552-5783 |
| Popis: | Purpose Previously, we have mapped amblyopic eye suppression within the central 20° of the visual field and observed a gradient of suppression that is strongest in central vision and weakens with increasing eccentricity. In this study, using a large dichoptic display, we extend our novel suppression mapping approach further into the periphery (from 20°-60°) to assess whether suppression continues to decline with eccentricity or plateaus. Methods Sixteen participants with amblyopia (10 with strabismus, 6 with anisometropia without strabismus; mean age: 37.9 ± 11 years) and six normal observers (mean age: 28.3 ± 5 years) took part. The visual stimulus (60° diameter), viewed from 57 cm, was composed of four concentric annuli (5° radius) with alternate contrast polarities starting from an eccentricity of 10°. Each annulus was divided into eight sectors subtending 45° of visual angle. Participants adjusted the contrast of a single sector presented to the fellow eye to match the perceived contrast of the remaining stimulus elements that were presented to the amblyopic eye. A matching contrast that was lower in the fellow eye than the amblyopic eye indicated suppression. Results Patients with strabismus exhibited significantly stronger interocular suppression than controls across all eccentricities (P = 0.01). Patients with anisometropia did not differ from controls (P = 0.58). Suppression varied significantly with eccentricity (P = 0.005) but this effect did not differ between patient groups (P = 0.217). Conclusions In amblyopia, suppression is present beyond the central 10° in patients with strabismus. Suppression becomes weaker at greater eccentricities and this may enable peripheral fusion that could be used by binocular treatment methods. |
| Databáze: | OpenAIRE |
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