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 PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wolffsohn, J. S. Articles by Yu, B. S.-y. Search for Related Content PubMed PubMed Citation Articles by Wolffsohn, J. S. Articles by Yu, B. S.-y.

Nearwork-Induced Transient Myopia in Preadolescent Hong Kong Chinese

¹From the Neurosciences Research Institute, School of Life and Health Sciences, Aston University, Birmingham, United Kingdom; and the ²Centre for Myopia Research, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hong Kong, China.

PURPOSE. To compare the magnitude and time course of nearwork-induced transient myopia (NITM) in preadolescent Hong Kong Chinese myopes and emmetropes.

METHOD. Forty-five Hong Kong Chinese children, 35 myopes and 10 emmetropes aged 6 to 12 years (median, 7.5), monocularly viewed a letter target through a Badal lens for 5 minutes at either 5.00- or 2.50-D accommodative demand, followed by 3 minutes of viewing the equivalent target at optical infinity. Accommodative responses were measured continuously with a modified, infrared, objective open-field autorefractor. Accommodative responses were also measured for a countercondition: viewing of a letter target for 5 minutes at optical infinity, followed by 3 minutes of viewing the target at a 5.00-D accommodative demand. The results were compared with tonic accommodation and both subject and family history of refractive error.

RESULTS. Retinal-blur–driven NITM was significantly greater in Hong Kong Chinese children with myopic vision than in the emmetropes after both near tasks, but showed no significant dose effect. The NITM was still evident 3 minutes after viewing the 5.00-D near task for 5 minutes. The magnitude of NITM correlated with the accommodative drift after viewing a distant target for more than 4 minutes, but was unrelated to the subjects’ or family history of refractive error.

CONCLUSIONS. In a preadolescent ethnic population with known predisposition to myopia, there is a significant posttask blur-driven accommodative NITM, which is sustained for longer than has previously been found in white adults.

This article has been cited by other articles:

				B. Vasudevan, K. J. Ciuffreda, and B. Gilmartin Sympathetic Inhibition of Accommodation after Sustained Nearwork in Subjects with Myopia and Emmetropia Invest. Ophthalmol. Vis. Sci., January 1, 2009; 50(1): 114 - 120. [Abstract] [Full Text] [PDF]

				B. Vasudevan and K. J. Ciuffreda Additivity of Near Work-Induced Transient Myopia and Its Decay Characteristics in Different Refractive Groups Invest. Ophthalmol. Vis. Sci., February 1, 2008; 49(2): 836 - 841. [Abstract] [Full Text] [PDF]

				H. Radhakrishnan, P. M. Allen, and W. N. Charman Dynamics of Accommodative Facility in Myopes Invest. Ophthalmol. Vis. Sci., September 1, 2007; 48(9): 4375 - 4382. [Abstract] [Full Text] [PDF]

				J. S. Wolffsohn, O. A. Hunt, S. Naroo, B. Gilmartin, S. Shah, I. A. Cunliffe, M. T. Benson, and S. Mantry Objective Accommodative Amplitude and Dynamics with the 1CU Accommodative Intraocular Lens. Invest. Ophthalmol. Vis. Sci., March 1, 2006; 47(3): 1230 - 1235. [Abstract] [Full Text] [PDF]

				L. N. Davies, J. S. Wolffsohn, and B. Gilmartin Cognition, Ocular Accommodation, and Cardiovascular Function in Emmetropes and Late-Onset Myopes Invest. Ophthalmol. Vis. Sci., May 1, 2005; 46(5): 1791 - 1796. [Abstract] [Full Text] [PDF]