Effects of muscarinic receptor modulators on ocular biometry of guinea pigs.

Saved in:

Bibliographic Details
Title:	Effects of muscarinic receptor modulators on ocular biometry of guinea pigs.
Authors:	Fang, Fang, Huang, Furong, Xie, Ruozhong, Li, Cheng, Liu, Yin, Zhu, Ying, Qu, Jia, Zhou, Xiangtian
Source:	Ophthalmic & Physiological Optics. Jan2015, Vol. 35 Issue 1, p60-69. 10p.
Subjects:	Muscarinic receptors, Visual accommodation, Pilocarpine, Refractive errors, Guinea pigs as laboratory animals
Abstract:	Purpose This study investigated whether pilocarpine and cyclopentolate induce changes in ocular biometry of guinea pigs, in order to understand if guinea pigs have a similar response to these two agents as humans do. Methods Under general anaesthesia, refraction, axial components and surface curvature in various optical interfaces of the eye were measured in 10 guinea pigs (age of 2 weeks) at baseline (0 min) and different time points (5, 10, 20, 30, 60, 90 min) after topical administration of pilocarpine or cyclopentolate. The interval between the two drug treatments for the same animals was at least 24 h. Results Eyes treated with pilocarpine developed approximately 6D myopia ( p < 0.001 from 0 to 90 min) with a decrease in anterior lens radius of curvature ( ALRC) ( p < 0.001 from 0 to 90 min, repeated measures anova). This myopic shift was moderately correlated to the decreased ALRC ( r2 = 0.48, p < 0.001). Furthermore, a small but significant increase in the VCD ( p < 0.001 from 0 to 30 min, repeated measures anova) with an unchanged AL ( p = 0.85 from 0 to 90 min, repeated measures anova) after the drug treatment suggested a transient and mild forward movement of the lens. Cyclopentolate dilated the pupil in all eyes ( p < 0.001 from 0 to 90 min, repeated measures anova) but did not change other ocular parameters. Conclusions The muscarinic agonist, pilocarpine induced a myopic shift mainly due to a decrease in ALRC, suggesting that guinea pigs have an accommodative mechanism similar to that in humans. The minimal changes produced by cyclopentolate could be due to the use of general anaesthesia, which may have reduced the susceptibility of the eye to topical cyclopentolate in the induction of cycloplegia. [ABSTRACT FROM AUTHOR]
	Copyright of Ophthalmic & Physiological Optics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database:	Psychology and Behavioral Sciences Collection

Description
Abstract:	Purpose This study investigated whether pilocarpine and cyclopentolate induce changes in ocular biometry of guinea pigs, in order to understand if guinea pigs have a similar response to these two agents as humans do. Methods Under general anaesthesia, refraction, axial components and surface curvature in various optical interfaces of the eye were measured in 10 guinea pigs (age of 2 weeks) at baseline (0 min) and different time points (5, 10, 20, 30, 60, 90 min) after topical administration of pilocarpine or cyclopentolate. The interval between the two drug treatments for the same animals was at least 24 h. Results Eyes treated with pilocarpine developed approximately 6D myopia ( p < 0.001 from 0 to 90 min) with a decrease in anterior lens radius of curvature ( ALRC) ( p < 0.001 from 0 to 90 min, repeated measures anova). This myopic shift was moderately correlated to the decreased ALRC ( r2 = 0.48, p < 0.001). Furthermore, a small but significant increase in the VCD ( p < 0.001 from 0 to 30 min, repeated measures anova) with an unchanged AL ( p = 0.85 from 0 to 90 min, repeated measures anova) after the drug treatment suggested a transient and mild forward movement of the lens. Cyclopentolate dilated the pupil in all eyes ( p < 0.001 from 0 to 90 min, repeated measures anova) but did not change other ocular parameters. Conclusions The muscarinic agonist, pilocarpine induced a myopic shift mainly due to a decrease in ALRC, suggesting that guinea pigs have an accommodative mechanism similar to that in humans. The minimal changes produced by cyclopentolate could be due to the use of general anaesthesia, which may have reduced the susceptibility of the eye to topical cyclopentolate in the induction of cycloplegia. [ABSTRACT FROM AUTHOR]
ISSN:	02755408
DOI:	10.1111/opo.12166