HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Kee, C.-s. Articles by Smith, E. L. Search for Related Content PubMed PubMed Citation Articles by Kee, C.-s. Articles by Smith, E. L., III

Temporal Constraints on Experimental Emmetropization in Infant Monkeys

¹From the College of Optometry, University of Houston, Houston, Texas; ²Vision CRC, University of New South Wales, Sydney, Australia; ³Department of Psychology, Stanford University, Stanford, California; and ⁴Department of Biology, City College, New York, New York.

PURPOSE. To characterize the temporal integration properties of the emmetropization process, the authors investigated the effects of brief daily interruptions of lens wear on the ocular compensation for negative lenses in infant rhesus monkeys.

METHODS. Eighteen monkeys wore –3 D lenses binocularly starting from approximately 3 weeks of age. Six of these monkeys wore the lenses continuously. For the other animals, the –3 D lenses were removed for four 15-minute periods each day. During these periods, the monkeys viewed through either zero-power lenses (n = 6) or +4.5 D lenses (n = 6). Three monkeys reared with binocular plano lenses and 16 monkeys reared normally served as controls. Refractive development was assessed by cycloplegic retinoscopy and A-scan ultrasonography.

RESULTS. As expected, the group of animals that wore the –3 D lenses continuously exhibited clear evidence of compensating axial myopia. These predictable myopic changes were mostly eliminated by the brief, daily periods of viewing through plano lenses. Interestingly, brief periods of viewing through +4.5 D lenses produced weaker protective effects.

CONCLUSIONS. Brief periods of unrestricted vision can prevent the axial myopia normally produced by long daily periods of imposed hyperopic defocus. Thus, the temporal integration properties of the emmetropization process normally reduce the likelihood that transient periods of hyperopic defocus will cause myopia.

This article has been cited by other articles:

				L.-F. Hung, R. Ramamirtham, J. Huang, Y. Qiao-Grider, and E. L. Smith III Peripheral Refraction in Normal Infant Rhesus Monkeys Invest. Ophthalmol. Vis. Sci., September 1, 2008; 49(9): 3747 - 3757. [Abstract] [Full Text] [PDF]