Document Detail


Myopes show increased susceptibility to nearwork aftereffects.
MedLine Citation:
PMID:  9727402     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
PURPOSE: Some aspects of accommodation may be slightly abnormal (or different) in myopes, compared with accommodation in emmetropes and hyperopes. For example, the initial magnitude of accommodative adaptation in the dark after nearwork is greatest in myopes. However, the critical test is to assess this initial accommodative aftereffect and its subsequent decay in the light under more natural viewing conditions with blur-related visual feedback present, if a possible link between this phenomenon and clinical myopia is to be considered. METHODS: Subjects consisted of adult late- (n = 11) and early-onset (n = 13) myopes, emmetropes (n = 11), and hyperopes (n = 9). The distance-refractive state was assessed objectively using an autorefractor immediately before and after a 10-minute binocular near task at 20 cm (5 diopters [D]). RESULTS: Group results showed that myopes were most susceptible to the nearwork aftereffect. It averaged 0.35 D in initial magnitude, with considerably faster posttask decay to baseline in the early-onset (35 seconds) versus late-onset (63 seconds) myopes. There was no myopic aftereffect in the remaining two refractive groups. CONCLUSIONS: The myopes showed particularly striking accommodatively related nearwork aftereffect susceptibility. As has been speculated and found by many others, transient pseudomyopia may cause or be a precursor to permanent myopia or myopic progression. Time-integrated increased retinal defocus causing axial elongation is proposed as a possible mechanism.
Authors:
K J Ciuffreda; D M Wallis
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Investigative ophthalmology & visual science     Volume:  39     ISSN:  0146-0404     ISO Abbreviation:  Invest. Ophthalmol. Vis. Sci.     Publication Date:  1998 Sep 
Date Detail:
Created Date:  1998-09-08     Completed Date:  1998-09-08     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  7703701     Medline TA:  Invest Ophthalmol Vis Sci     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1797-803     Citation Subset:  IM    
Affiliation:
Department of Vision Sciences, State College of Optometry, State University of New York, New York 10010, USA.
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MeSH Terms
Descriptor/Qualifier:
Accommodation, Ocular*
Adult
Afterimage / physiology*
Female
Humans
Hyperopia / physiopathology
Male
Myopia / physiopathology*
Refraction, Ocular
Vision, Binocular
Visual Acuity
Grant Support
ID/Acronym/Agency:
T35 EY07079-12/EY/NEI NIH HHS

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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