Non-contact measurement of linear external dimensions of the mouse eye

• Type of Material: Article
• Authors: Jeffrey Wisard, Emory University; Micah A. Chrenek, Emory University; Charles Wright, Emory University; Nupur Dalal, Emory University; Machelle Pardue, Emory University; Jeffrey Boatright, Emory University; John Nickerson, Emory University
• Language: English
• Date: 2010-03-30
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2010 Elsevier B.V. All rights reserved
• License: Creative Commons Attribution-NonCommerical-NoDerivs 3.0 Unported
• Final Published Version (URL): http://dx.doi.org/10.1016/j.jneumeth.2010.01.006
• Title of Journal or Parent Work: Journal of Neuroscience Methods
• ISSN: 0165-0270
• Volume: 187
• Issue: 2
• Start Page: 156
• End Page: 166
• Grant/Funding Information: This work was supported by the National Eye Institute (R01EY016470 (JMN), R01EY014026 (JHB), R01EY016435 (MTP), P30EY006360, R24EY017045, T32EY007092, an unrestricted grant to the Department of Ophthalmology at Emory University from Research to Prevent Blindness, Inc., the Foundation Fighting Blindness, the Katz Foundation, Fight for Sight, the Knights Templar of Georgia, and the Rehabilitation Research and Development Center of Excellence, Atlanta VA Hospital.
• Research Categories: Health Sciences, Rehabilitation and Therapy; Health Sciences, Opthamology

Abstract

Biometric analyses of quantitative traits in eyes of mice can reveal abnormalities related to refractive or ocular development. Due to the small size of the mouse eye, highly accurate and precise measurements are needed to detect meaningful differences. We sought a non-contact measuring technique to obtain highly accurate and precise linear dimensions of the mouse eye. Laser micrometry was validated with gauge block standards. Simple procedures to measure eye dimensions on three axes were devised. Mouse eyes from C57BL/6J and rd10 on a C57BL/6J background were dissected and extraocular muscle and fat removed. External eye dimensions of axial length (anterior-posterior (A-P) axis) and equatorial diameter (superior-inferior (S-I) and nasal-temporal (N-T) axes) were obtained with a laser micrometer. Several approaches to prevent or ameliorate evaporation due to room air were employed. The resolution of the laser micrometer was less than 0.77 microns, and it provided accurate and precise non-contact measurements of eye dimensions on three axes. External dimensions of the eye strongly correlated with eye weight. The N-T and S-I dimensions of the eye correlated with each other most closely from among the 28 pair-wise combinations of the several parameters that were collected. The equatorial axis measurements correlated well from the right and left eye of each mouse. The A-P measurements did not correlate or correlated poorly in each pair of eyes. The instrument is well suited for the measurement of enucleated eyes and other structures from most commonly used species in experimental vision research and ophthalmology.