“E” selections in the Glossary of Terms for
Anatomy, Physiology & Pathology of the Human Eye

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E, vitamin
see vitamin E

eccentric fixation
eye fixation with a point on the retina other than the fovea or macula; often found in a strabismic eye or in an eye with longstanding macular pathology; causes the visual acuity in that eye to be less than it would be if a healthy macula were being used, since visual acuity drops markedly the further away from the fovea or macula the image is located

an abnormal infiltration and excess accumulation of serous fluid in body tissue or in a serous cavity, causing swelling; dropsy or hydrops

edema, corneal
infusion of fluid (such as aqueous humor or tears) into the cornea, causing swelling, haziness, and decreased vision

edema, cystoid macular (CME)
painless disorder affecting the macula or central retina where multiple cyst-like (cystoid) formations appear in the macula and cause retinal swelling or edema with resultant blurred or decreased central vision; may accompany a variety of diseases such as retinal vein occlusion, uveitis, or diabetes, or can occur following cataract surgery

edema, macular
infusion into the macula of serum leaked from blood vessels underneath the macula, causing macular swelling and decreased vision

the sudden obstruction of a blood vessel by an embolus

an abnormal particle (such as cholesterol, platelet clump, blood clot, calcium fleck, an air bubble, fat, or some combination of these) circulating in the blood

no refractive error, where light coming from a distant object and entering the eye focuses upon the retina while the crystalline lens in its most relaxed (thinnest) state

concurrent inflammation of the brain and spinal cord

endothelium, corneal
a single layer of cells of mesoblastic origin which line the posterior surface of the cornea

endothelium, iridial
a single layer of cells of mesoblastic origin which line the anterior surface of the iris

a watering of the eyes, usually with spillage over the lower eyelids, due to excessive secretion of tears or to obstruction of the lacrimal passages

epiretinal membrane (ERM)
a membrane of scar tissue that forms over the retina following irritation of that area by a posterior vitreous detachment; commonly known as a “macular pucker” if the macula is involved

an inflammation (usually localized) of the episclera, a thin layer of tissue covering the sclera and containing many blood vessels that nourish the sclera; cause is unknown, but can be associated with certain diseases such as rheumatoid arthritis, Sjogren’s syndrome, syphilis, herpes zoster, and tuberculosis

epithelium, corneal
a membranous cellular tissue that covers the anterior surface of the cornea

epithelium, iridial
a membranous cellular tissue that covers the posterior surface of the iris

epithelium, pigmented
supporting cells for the neural portion of the retina (photopigment regeneration, blood); dark with melanin which decreases light scatter within the eye

a strabismus where the deviating eye turns inward (toward the nose), as compared to the other eye which remains pointing straight ahead

a strabismus where the deviating eye turns outward (away from the nose), as compared to the other eye which remains pointing straight ahead

external limiting membrane
retinal layer separating the layer of outer and inner segments of cone and rod photoreceptors from the layer of photoreceptor cell bodies; composed of junctional complexes of rods and cones with Müller cells

extracapsular cataract extraction (ECCE)
extraction of a cataract, usually by “phacoemulsification” (disintegration of the lens by ultrasonic vibrations and subsequent suction of the particles out of the eye) of the nucleus and cortex of the crystalline lens, leaving behind the posterior portion of the capsule into which an artificial implant lens is placed

extraction, extracapsular cataract
see extracapsular cataract extraction (ECCE)

extraction, intracapsular cataract
see intracapsular cataract extraction (ICCE)

extraocular muscles
six muscles (medial rectus, lateral rectus, superior rectus, inferior rectus, superior oblique, and inferior oblique) which serve to move an eye by rotating it about its vertical, horizontal, and antero-posterior axes

eye color
see color, eye

spectacles; lenses ground to the specifications of a prescription which, when mounted into frames and worn on the face, aid in refocusing the light entering each eye onto the retina at the back of the eye, providing clear vision

palpebra; either of the movable lids of skin and muscle that can be closed over the eyeball, providing eye protection and distribution of tears over the cornea while blinking

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