Biomaterial Database

Tear flow under hydrogel contact lenses. 1979

K A Polse

The tear replenishment rate under three different hydrogel lenses was determined with a slit lamp modified to serve as a fluorophotometer. Fractional tear volume replenishment rates under these lenses averaged 0.011 per blink, which is significantly lower than the 0.10 to 0.20 per blink reported for rigid lenses. These data suggest that the amount of oxygen delivered to the cornea by tear pumping for gel lenses is relatively small and that oxygen received by the cornea covered by a gel lens comes principally by diffusion through the material.

UI	MeSH Term	Description	Entries
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D003263	Contact Lenses, Hydrophilic	Soft, supple contact lenses made of plastic polymers which interact readily with water molecules. Many types are available, including continuous and extended-wear versions, which are gas-permeable and easily sterilized.	Lenses, Contact, Hydrophilic,Soft Contact Lenses,Hydrophilic Contact Lens,Soft Contact Lens,Contact Lens, Hydrophilic,Contact Lens, Soft,Contact Lenses, Soft,Hydrophilic Contact Lenses,Lens, Hydrophilic Contact,Lens, Soft Contact,Lenses, Hydrophilic Contact,Lenses, Soft Contact
D003315	Cornea	The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)	Corneas
D005470	Fluorometry	An analytical method for detecting and measuring FLUORESCENCE in compounds or targets such as cells, proteins, or nucleotides, or targets previously labeled with FLUORESCENCE AGENTS.	Fluorimetry,Fluorometric Analysis,Analysis, Fluorometric
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013666	Tears	The fluid secreted by the lacrimal glands. This fluid moistens the CONJUNCTIVA and CORNEA.	Meibomian Lipids,Meibum,Lipid, Meibomian,Meibomian Lipid,Tear