Devices implanted to control intraocular pressure by allowing aqueous fluid to drain from the anterior chamber. (Hoffman, Pocket Glossary of Ophthalmologic Terminology, 1989)

Visible accumulations of fluid within or beneath the epidermis.

An ocular disease, occurring in many forms, having as its primary characteristics an unstable or a sustained increase in the intraocular pressure which the eye cannot withstand without damage to its structure or impairment of its function. The consequences of the increased pressure may be manifested in a variety of symptoms, depending upon type and severity, such as excavation of the optic disk, hardness of the eyeball, corneal anesthesia, reduced visual acuity, seeing of colored halos around lights, disturbed dark adaptation, visual field defects, and headaches. (Dictionary of Visual Science, 4th ed)

The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball.