Abstract
Abstract: :
Purpose: To assess the presence of uveoscleral outflow in the mouse eye by monitoring the movement of intracamerally injected fluorescent dextran within the trabecular meshwork, ciliary muscle, choroid and sclera. Methods: Anesthetized NIH Swiss mice received intracameral injection of 70kDa dextran conjugated to Alexa568 and to lysine. After survival times of 10, 20, 60, and 120 minutes, the experiments were terminated by transcardial perfusion with buffered 4% paraformaldehyde. Paraffin sections of the eyes were prepared and then analyzed by fluorescence microscopy. Results: Fluorescent tracer in the eyes incubated for 10 minutes was prominent in the iris root and ciliary processes, and of moderate intensity in the trabecular meshwork and adjacent cornea and sclera. At 20 minutes, strong labeling was observed in the ciliary processes, the ciliary muscle, and extending from the ciliary muscle tail for a short distance into the anterior choroid. At 60 minutes, the label in the choroid extended much farther away from the ciliary muscle and sclera over the labeled choroid became fluorescent. The intensity of the label within the ciliary processes of these eyes was substantially reduced when compared with the 20 minute eyes. At 120 minutes, label was observed only within trabecular meshwork and Schlemm's canal. Conclusion: The label passed sequentially first from the anterior chamber to the trabecular meshwork and ciliary processes, next to the ciliary muscle and anterior choroid, and eventually into choroid and sclera near the equator. These results indicate that at least a portion of the aqueous humor exits the mouse eye via uveoscleral outflow.
Keywords: 324 aqueous • 502 outflow: ciliary muscle • 315 anatomy