Sign-dependent changes in retinal electrical activity with positive and negative defocus in the human eye
| Autor: | On-ying Wong, Henry Ho-lung Chan, Wing-cheung Ho, Chea-Su Kee, Sze-wai Wong, Yuen-chi Chan |
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| Rok vydání: | 2011 |
| Předmět: |
Adult
medicine.medical_specialty Ocular health Neural activity Mydriatics genetic structures Mathematics::Analysis of PDEs Physics::Optics Multifocal electroretinogram (mfERG) Fixation Ocular Optical defocus Concentric ring Retina chemistry.chemical_compound Ocular physiology Young Adult Optics Ophthalmology medicine Electroretinography Reaction Time Humans Nonlinear Sciences::Pattern Formation and Solitons Physics business.industry Global flash Retinal Sensory Systems eye diseases Amplitude medicine.anatomical_structure chemistry Fixation (visual) Human eye sense organs business Photic Stimulation |
| Zdroj: | Vision research. 52(1) |
| ISSN: | 1878-5646 |
| Popis: | The purpose of this study was to investigate the effect of optical defocus on changes of electrical response as a function of retinal region. Twenty-three subjects (aged 19–25year) with normal ocular health were recruited for global flash multifocal electroretinogram (mfERG) recordings under control (fully corrected) condition, and short-term positive defocus (+2D and +4D) and negative defocus (−2D and −4D) conditions. The amplitudes and implicit times of direct (DC) and induced (IC) components of mfERG responses were pooled into six concentric rings for analyses. The mfERG responses demonstrated more significant changes in amplitude in paracentral retinal regions than in the central regions under defocused conditions. The paracentral DC amplitude showed a significant reduction under negative defocus conditions. In contrast, the paracentral IC amplitude showed a significant increment under positive defocus conditions. Interestingly, the central IC response showed significant reduction in amplitude only to negative defocus, while increasing its amplitude to positive defocus. However, the DC and IC implicit times were virtually unaffected under defocused conditions. Our findings suggest that human retina is able to differentiate defocused signals and to identify positive and negative defocus. It shows that paracentral retina reacts more vigorously to optical defocus than does central retina. |
| Databáze: | OpenAIRE |
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