Ketamine-xylazine anesthesia causes hyperopic refractive shift in mice.
Mice have increasingly been used as a model for studies of myopia. The key to successful use of mice for myopia research is the ability to obtain accurate measurements of refractive status of their eyes. In order to obtain accurate measurements of refractive errors in mice, the refraction needs to be performed along the optical axis of the eye. This represents a particular challenge, because mice are very difficult to immobilize. Recently, ketamine-xylazine anesthesia has been used to immobilize mice before measuring refractive errors, in combination with tropicamide ophthalmic solution to induce mydriasis. Although these drugs have increasingly been used while refracting mice, their effects on the refractive state of the mouse eye have not yet been investigated. Therefore, we have analyzed the effects of tropicamide eye drops and ketamine-xylazine anesthesia on refraction in P40 C57BL/6J mice. We have also explored two alternative methods to immobilize mice, i.e. the use of a restraining platform and pentobarbital anesthesia. We found that tropicamide caused a very small, but statistically significant, hyperopic shift in refraction. Pentobarbital did not have any substantial effect on refractive status, whereas ketamine-xylazine caused a large and highly significant hyperopic shift in refraction. We also found that the use of a restraining platform represents good alternative for immobilization of mice prior to refraction. Thus, our data suggest that ketamine-xylazine anesthesia should be avoided in studies of refractive development in mice and underscore the importance of providing appropriate experimental conditions when measuring refractive errors in mice.
Tkatchenko
Tatiana V
TV
Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
Tkatchenko
Andrei V
AV
D000778:Anesthetics, Dissociative / Q000494:pharmacology; D000818:Animals; D005123:Eye / Q000187:drug effects; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D007103:Immobilization / Q000379:methods*; D007649:Ketamine / Q000494:pharmacology*; D051379:Mice; D010424:Pentobarbital / Q000494:pharmacology; D012029:Refraction, Ocular / Q000187:drug effects*; D012030:Refractive Errors / Q000139:chemically induced*; D014991:Xylazine / Q000494:pharmacology*
D000778:Anesthetics, Dissociative; D006993:Hypnotics and Sedatives; D014991:Xylazine; D007649:Ketamine; D010424:Pentobarbital
Invest Ophthalmol Vis Sci. 2008 Feb;49(2):706-12
18235018
J Pharmacol Exp Ther. 1981 Jul;218(1):188-92
6113279
Vision Res. 2008 Mar;48(7):904-16
18289630
Anat Anz. 1981;150(5):498-515
7342796
J Vet Pharmacol Ther. 1981 Jun;4(2):97-101
6130161
J Vet Pharmacol Ther. 1981 Sep;4(3):209-14
7349335
Exp Eye Res. 1970 Jul;10(1):19-30
5456775
Phys Med Biol. 2002 Aug 21;47(16):2863-77
12222851
Ophthalmic Physiol Opt. 2005 Jul;25(4):340-5
15953119
Science. 1970 May 1;168(3931):605-6
5436596
Ophthalmic Physiol Opt. 1986;6(2):187-96
3748565
Addict Biol. 2001 Sep;6(4):373-376
11900615
Exp Eye Res. 1986 Apr;42(4):331-7
3754819
Nature. 1979 Apr 12;278(5705):645-6
450064
Br J Pharmacol. 1999 Dec;128(7):1467-76
10602325
Exp Eye Res. 1989 Nov;49(5):861-71
2591501
Invest Ophthalmol Vis Sci. 1995 Mar;36(3):703-7
7890500
Invest Ophthalmol Vis Sci. 2010 Jan;51(1):21-7
19661239
Nature. 1977 Mar 3;266(5597):66-8
402582
Exp Eye Res. 1967 Oct;6(4):368-75
6060548
Invest Ophthalmol Vis Sci. 2010 Mar;51(3):1297-303
19875658
Vision Res. 1999 Jun;39(11):1991-2015
10343784
Anat Rec. 1956 Feb;124(2):145-63
13302815
Invest Ophthalmol Vis Sci. 2003 Jan;44(1):32-6
12506052
Proc Natl Acad Sci U S A. 2000 Jun 6;97(12):6245-7
10841527
Invest Ophthalmol Vis Sci. 2001 Jul;42(8):1841-6
11431452
Clin Exp Optom. 2008 May;91(3):296-301
18201223
Invest Ophthalmol Vis Sci. 2008 Jun;49(6):2531-40
18408189
Neuroscience. 1989;30(3):827-36
2788830
Teratology. 1968 May;1(2):193-9
5759135
Invest Ophthalmol Vis Sci. 1992 Aug;33(9):2603-11
1639607
Invest Ophthalmol Vis Sci. 2008 Dec;49(12):5208-14
18689702
Vision Res. 2004;44(16):1857-67
15145680
Science. 1978 Sep 29;201(4362):1249-51
694514
Brain Res Mol Brain Res. 2001 Nov 1;95(1-2):86-95
11687279
Eur J Neurosci. 2003 Jan;17(1):119-27
12534975
Trends Neurosci. 2000 Feb;23(2):60-8
10652546
Phys Med Biol. 1995 Jun;40(6):963-78
7659735
Brain Res. 1977 Mar 18;124(1):154-7
843938
Invest Ophthalmol Vis Sci. 1989 Nov;30(11):2392-402
2807795
Genetics. 1942 May;27(3):339-48
17247045
Optom Vis Sci. 2004 Feb;81(2):99-110
15127929
Appl Opt. 1989 Mar 15;28(6):1061-77
20548621