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Abstract #45720 Published in IGR 13-2
Outflow physiology of the mouse eye: Pressure dependence and washout
Lei Y; Overby DR; Boussommier-Calleja A; Daniel Stamer W; Ross Ethier CInvestigative Ophthalmology and Visual Science 2011; 52: 1865-1871
PURPOSE. Mice are commonly used in glaucoma research, but relatively little is known about aqueous outflow dynamics in the species. To facilitate future use of the mouse as a model of aqueous humor outflow, several fundamental physiological parameters were measured in the mouse eye. METHODS. Eyes from adult mice of either sex (C57BL/6 background) were enucleated, cannulated with a 33-gauge needle, and perfused at constant pressure while inflow was continuously measured. RESULTS. At 8 mm Hg, total outflow facility (C(total)) was 0.022 (plus or minus) 0.005 (mu)L/min/mm Hg (all values mean (plus or minus) SD; n =21). The flow-pressure relationship was linear up to 35 mm Hg. The conventional outflow facility (C(conv)) was 0.0066 (plus or minus) 0.0009 (mu)L/min/mm Hg, and the unconventional outflow (Fu) was 0.114 (plus or minus) 0.019 (mu)L/min, both measured at room temperature. At 8 mm Hg, 66% of the outflow was via the unconventional pathway. In a more than 2-hour-long perfusion at 8 mm Hg, the rate of facility change was 2.4% (plus or minus) 5.4% (n = 11) of starting facility per hour. The ocular compliance (0.086 (plus or minus) 0.017 (mu)L/mm Hg; n = 5) was comparable to the compliance of the perfusion system (0.100 (plus or minus) 0.004 (mu)L/mm Hg). CONCLUSIONS. Mouse eyes are similar to human eyes, in that they have no detectable washout rate and a linear pressure-flow relationship over a broad range of intraocular pressures. Because of the absence of washout and the apparent presence of a true Schlemm's canal, the mouse is a useful model for studying the physiology of the inner wall of Schlemm's canal and the conventional outflow tissues.
C. R. Ethier. Department of Bioengineering, Imperial College London, London, SW7 2AZ, United Kingdom. Email: r.ethier@imperial.ac.uk
Classification:
2.6.2.1 Trabecular meshwork (Part of: 2 Anatomical structures in glaucoma > 2.6 Aqueous humor dynamics > 2.6.2 Outflow)
5.1 Rodent (Part of: 5 Experimental glaucoma; animal models)