Biomaterial Database

Evaluating surgically induced astigmatism. 1994

T Olsen, and M Dam-Johansen

Department of Ophthalmology, Aarhus University Hospital, Denmark.

Using a modification of vector analysis for calculating surgically induced astigmatism, we describe a simple method that divides the induced cylinder into two orthogonal components. This decomposition allows with-the-rule and against-the-rule astigmatic changes to be calculated for individual case analysis, as well as for statistical analysis of aggregate data. Because it is based on the true induced cylinder, as determined by optical principles, this method overcomes some of the problems associated with earlier methods of evaluating surgically induced astigmatism.

UI	MeSH Term	Description	Entries
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D012029	Refraction, Ocular	Refraction of LIGHT effected by the media of the EYE.	Ocular Refraction,Ocular Refractions,Refractions, Ocular
D002387	Cataract Extraction	The removal of a cataractous CRYSTALLINE LENS from the eye.	Enzymatic Zonulolysis,Phakectomy,Cataract Extractions,Enzymatic Zonulolyses,Extraction, Cataract,Extractions, Cataract,Phakectomies,Zonulolyses, Enzymatic,Zonulolysis, Enzymatic
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
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001251	Astigmatism	Unequal or irregular curvature of the CORNEA (Corneal astigmatism) and/or the EYE LENS (Lenticular astigmatism) resulting in REFRACTIVE ERROR.	Corneal Astigmatism,Hyperopic Astigmatism,Lenticular Astigmatism,Mixed Astigmatism,Myopic Astigmatism,Oblique Astigmatism,Astigmatism, Corneal,Astigmatism, Hyperopic,Astigmatism, Lenticular,Astigmatism, Mixed,Astigmatism, Myopic,Astigmatism, Oblique,Hyperopic Astigmatisms,Mixed Astigmatisms,Myopic Astigmatisms,Oblique Astigmatisms