I
“I” selections in the Glossary of Terms for
Anatomy, Physiology & Pathology of the Human Eye
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A B C D E F G H I J K L M
N O P Q R S T U V W X Y Z
- implant, lens
- see intraocular lens
- inferior oblique muscle
- an extraocular muscle in the orbit, originating from the orbital surface of the maxilla, lateral to the lacrimal groove; the only extrinsic eye muscle not originating in the annulus of Zinn; innervated by the oculomotor nerve (cranial nerve III); extorts, elevates, and abducts the eye (rotates the top of the eye outward, turns the front of the eye upward, and turns the front of the eye outward)
- inferior rectus muscle
- an extraocular muscle in the orbit, originating in the annulus of Zinn; innervated by the oculomotor nerve (cranial nerve III); depresses, extorts, and adducts the eye (turns the front of the eye downward, rotates the top of the eye outward, and turns the front of the eye inward)
- inflammation
- a local response to cellular injury that is marked by capillary dilatation, leukocytic infiltration, redness, heat, pain, swelling, and often loss of function; serves as a mechanism initiating the elimination of noxious agents and of damaged tissue
- infrared (IR) radiation
- see radiation, infrared (IR)
- inner nuclear layer
- layer of the retina containing the cell bodies of horizontal cells, bipolar cells, amacrine cells, and Müller cells
- inner plexiform layer
- layer of the retina containing the axons of bipolar cells and amacrine cells and the dendrites of ganglion cells
- internal limiting membrane
- the innermost layer of the retina, separating the retina from the vitreous humor
- internal tunic
- see tunica intima
- intima, tunica
- see tunica intima
- intracapsular cataract extraction (ICCE)
- removal of the entire cataractous crystalline lens, usually by “cryoextraction” (utilization of a cryoprobe whose refrigerated tip adheres to and freezes tissue of the lens, permitting its removal); no longer the preferred method of cataract extraction, having been replaced by extracapsular cataract extraction (ECCE)
- intraocular lens
- a small plastic lens, made of a hard plastic (polymethyl methacrylate or PMMA), silicone, acrylic, or hydrogel material, implanted into an eye after cataract surgery to replace crystalline lens which has been removed
- intraocular pressure (IOP)
- the pressure within the eyeball that gives it a round firm shape, regulated by the rate at which aqueous humor enters and leaves the eye
- iodopsin
- a violet photosensitive pigment found in the retinal cone photoreceptors that is similar to rhodopsin (in rod photoreceptors) but is more labile; contains photopsin (a protein) and retinene (a light absorbing compound which is derived from Vitamin A); important in photopic vision
- irido-corneal angle
- the angle formed by the junction of the iris and the cornea
- iridocyclitis
- inflammation of the iris and the ciliary body
- iris
- the opaque muscular contractile diaphragm that is suspended in the aqueous humor in front of the lens of the eye; perforated by the pupil and continuous peripherally with the ciliary body; possesses a deeply pigmented posterior surface, which excludes the passage of light except through the pupil, and a colored anterior surface which determines the color of the eye
- iris bombe
- a condition in which the iris is bowed forward by an accumulation of fluid between the iris and the crystalline lens
- iritis
- inflammation of the iris; can be caused by systemic diseases (such as rheumatoid arthritis), systemic infections (such as measles, syphilis, and tuberculosis), trauma, or idiopathic (unknown) sources
- isotonic
- having an osmotic pressure equal to that of the surrounding fluid or medium
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