Influence of accommodation on the anterior and posterior cornea
PURPOSE: To evaluate whether significant change occurs in the topography of the anterior or posterior cornea or in corneal thickness with accommodation. SETTING: Contact Lens and Visual Optics Laboratory, School of Optometry, Queensland University of Technology, Brisbane, Queensland, Australia. METHODS: Corneal data were acquired for 12 young, healthy emmetropic subjects under 2 accommodation levels (relaxed and approximately 5.0 diopters) using a rotating Scheimpflug camera. Anterior and posterior corneal elevation and sagittal curvature data as well as pachymetry data were analyzed to evaluate changes associated with accommodation. Corneal elevation data were also analyzed using a recentering procedure designed to minimize the effect of ocular micromovements between measurements. RESULTS: Changes in corneal parameters resulting from accommodation were small and generally insignificant. The mean change in pachymetry was 0.49 microm +/- 2.62 (SD) across an 8.0 mm pachymetry map. No significant change was found in the best-fit corneal spherocylinder (anterior and posterior cornea) (P>.05). Small changes were found in the corneal cylinder axis, indicative of small cyclotorsional eye movements accompanying accommodation. The mean changes in corneal elevation were 0.09 +/- 0.41 microm (anterior cornea) and 0.17 +/- 0.65 microm (posterior cornea). Only 0.50% (anterior cornea) and 0.27% (posterior cornea) of corneal elevation data points exhibited a statistically significant change with accommodation. Recentering the corneal elevation data led to a reduction in the magnitude of change in corneal elevation with accommodation. CONCLUSIONS: Small cyclotorsional eye movements occurred with accommodation. When these eye movements were accounted for in data analysis, no consistent significant change in the topography of the cornea was found with accommodation across an 8.0 to 9.0 mm corneal diameter.
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|Item Type:||Journal Article|
|Additional Information:||For more information, please refer to the journal’s website (see hypertext link) or contact the author.|
|Subjects:||Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > OPTOMETRY AND OPHTHALMOLOGY (111300)|
Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > OPTOMETRY AND OPHTHALMOLOGY (111300) > Vision Science (111303)
|Divisions:||Current > Research Centres > Centre for Health Research|
Current > QUT Faculties and Divisions > Faculty of Health
Current > Institutes > Institute of Health and Biomedical Innovation
|Copyright Owner:||Copyright 2007 Elsevier|
|Deposited On:||21 Jan 2008|
|Last Modified:||29 Feb 2012 23:36|
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