Glossary Flashcards
Ansio -
unequal
Blepharo -
eyelid
Cor -
pupil
Cyclo -
ciliary body
Dacryo -
tear lacrimation
Hyal -
vitreous
Hyp -
anterior chamber or under
Irido -
iris
Kerato -
cornea
ophthalmo-
globe or eye
Papilla-
optic disc
Phaco-
lens
Phako-
lens
Tarso-
eyelid
Ablation:
removal or destruction of part of the body.
Accomidation:
adjustments of the eye for seeing at different distances, usually accomplished by changes in the shape of the lens through action of the ciliary muscle, which results in focusing a clear image on the retina.
Acuity:
visual ability to distinguish shapes
Adnexa:
accessory structures of the eye (eyelids, conjunctiva, extraocular muscles, glands of the orbit, and nasolacrimal system).
Albinism:
a congenital absence of pigment. This is may be appreciated in the iris (which appears pink) and the fundus (in which the choroid is easily seen).
Anisocoria:
unequal or asymmetric pupils.
Ankyloblepharon:
adhesion between the eyelid margins; physiologic in kittens and puppies for the first 10-14 days of life.
Anophthalmia:
complete absence of the eye; anophthalmos.
Anterior chamber:
space within the eye bounded anteriorly by the cornea and posteriorly by the iris; filled with aqueous humor.
Anterior segment:
collective term for those parts of the eye anterior to the vitreous; consisting of the lens, ciliary body, iris, anterior chamber, cornea, and anterior sclera.
Aphakia:
absence of a lens.
Aphakic crescent:
a visible crescent between the iris and lens equator due to subluxation of the lens.
Aqueous flare:
visualization of a beam of light as it passes through the usually transparent aqueous of the anterior chamber (Tyndall effect); seen with an increase in protein and/or cells; represents disruption of the blood-aqueous barrier.
Aqueous humor:
clear watery fluid produced by the ciliary body that occupies the anterior and posterior chambers of the eye; egresses through the iridocorneal angle.
Asteroid hyalosis:
spherical and stellate calcium-lipid opacities in an otherwise normal vitreous; common in older animals
Astigmatism:
refractive error which prevents the light rays from coming to a single focus on the retina because of different degrees of refraction in the various meridians of the cornea.
Binocular vision:
the ability to use two eyes simultaneously to focus on the same object; fusion of these two images by the brain allows for stereopsis and depth perception.
Biomicroscopy:
microscopic examination of the various ocular structures in the living state, using a slit-lamp biomicroscope.
Blepharitis:
inflammation of the eyelids.
Blepharospasm:
spasm of the orbicularis oculi muscle resulting in eyelid closure; squinting.
Bullous keratopathy:
formation of vesicles (blisters) on or in the cornea.
Buphthalmos:
enlargement of the eye, due to glaucoma.
Canthotomy:
incision of the canthus, often to provide surgical visualization or access.
Canthus:
the angle at the medial and lateral ends of the palpebral fissure where the upper and lower eyelids join; specified as lateral or temporal and medial or nasal.
Caruncle:
a small piece of normal skin at the medial canthus from which hairs often protrude.
Cataract:
any opacity of the lens or lens capsule, or both.
Intumescent cataract:
swollen, enlarged; often seen with rapid onset diabetic cataracts.
Incipient cataract:
opacity involving less than 10-15% of lens volume.
Immature cataract:
cataractous change between incipient stage and complete cataract (15-99% of lens volume affected); hallmark feature is presence of tapetal reflex.
Mature cataract:
opacity involving the entire lens volume (100%), completely obscuring tapetal reflection.
Hypermature cataract:
liquefaction of lens due to proteolysis (lens resorption), resulting in reduction in lens volume, wrinkling of lens capsule, and sometimes visible tapetal reflection.
Morgagnian cataract:
hypermature, partially liquefied cataract in which the nucleus falls ventrally.
Chalazion:
lipogranuloma of a meibomian gland due to impaction of secretions.
Chemosis:
conjunctival edema.
“Cherry eye”:
lay term for prolapsed gland of the third eyelid. Diagram to the right
Chorioretinitis:
inflammation of the choroid and retina.
Choroid:
posterior portion of the uvea located between the retina and sclera; furnishes nourishment to the retina and vitreous body.
Ciliary body:
portion of the uveal tract between the iris and the choroid, consisting of ciliary muscles and ciliary processes that produce aqueous humor.
Cilium (pleural cilia):
eyelash
Collyrium:
eye wash
Coloboma:
: a congenital fissure or cleft of any part of the eye or eyelid. A typical coloboma is due to incomplete closure of the fetal fissure (generally at the 6 o’clock position) while an atypical coloboma occurs in another location.
Conjunctiva:
mucous membrane lining the eyelids (palpebral or third eyelid conjunctiva) and covering the anterior sclera (bulbar conjunctiva).
Conjunctival fornix:
the reflection of the conjunctiva from the eyelid (palpebral) to the globe (bulbar).
Corectopia:
displacement of the pupil from its normal position.
Cornea:
the clear, transparent anterior portion of the fibrous tunic of the eye.
Corneal degeneration:
unilateral or bilateral keratitis characterized by corneal edema, mineral or lipid deposits, and sometimes neovascularization.
Corneal dystrophy:
bilateral, hereditary, non-inflammatory corneal disease involving the epithelium, stroma, or endothelium.
Corneal reflex:
closure of the eyelids and globe retraction induced by a gentle touching of the cornea with wisps of cotton or use of a corneal esthesiometer.
Corpora nigrum (granula iridica):
irregular cystic dilations on the pupillary margin of the iris in large herbivores; most notable dorsally, but also typically present ventrally.
Cortical blindness:
blindness caused by a lesion in the occipital cortex.
Cyclitis:
inflammation of the ciliary body.
Cyclocryotherapy:
application of an ultra-cold probe on the sclera to freeze and destroy the ciliary body epithelium to reduce aqueous humor formation for the control of glaucoma.
Cyclophotocoagulation:
similar to cyclocryotherapy but utilizing a laser probe to destroy the ciliary body epithelium. Usually performed with a diode ophthalmic laser.
Cyclodialysis:
the establishment of communication between the anterior chamber and the suprachoroidal space to reduce intraocular pressure.
Cycloplegia:
paralysis of the ciliary muscle, resulting in loss of accommodation; often induced to limit discomfort due to ciliary spasm that is associated with anterior uveitis.
Cycloplegic or Parasympatholytic:
a drug that temporarily paralyzes the ciliary muscle; pupillary dilatation also results due to iris sphincter paralysis. Examples include atropine and tropicamide.
Dacryoadenitis:
inflammation of the lacrimal gland or gland of the third eyelid.
Dacryocystitis:
inflammation of the lacrimal sac and/or nasolacrimal duct.
Dark adaptation:
the ability of the retina and pupil (iris) to adjust to decreased illumination.
Dazzle reflex:
subcortical reflex in which a rapid eye blink is elicited by a bright light shone into an eye.
Decussation:
a crossing of nerve fibers or tracts from one side of the nervous system to the contralateral side; as in the crossing over of optic nerve fibers at the optic chiasm.
Dermoid:
a congenital growth (choristoma) consisting of skin and its dermal appendages. Usually located near or connected to lateral canthus involving cornea, sclera, and conjunctiva.
Descemetocele:
a deep corneal ulcer characterized by exposure and possible protrusion of Descemet’s membrane.
Descemet’s membrane:
the basement membrane of the corneal endothelium.
Diopter:
the unit of measurement of the refractive power of lenses; equal to the reciprocal of the focal length of the lens expressed in meters. For example, one diopter (D) has a focal length of one meter and two diopters have a focal length of .5 meters.
Distichiasis:
condition in which a single cilium emerges from one or more meibomian gland orifices.
Districhiasis:
condition in which multiple cilia emerge from one meibomian gland orifice.
Dyscoria:
abnormally shaped pupil.
Ectasia:
dilatation; distention; usually pertaining to cornea or sclera and resulting from acquired weakness or congenital malformation.
Ectopic cilia:
cilia protruding through palpebral conjunctiva, often causing corneal ulceration and/or pain.
Ectropion:
an eversion or turning out of the eyelid.
Ectropion uvea:
eversion of posterior iridal pigmented tissue around the pupillary margin into the anterior chamber; usually associated with anterior uveitis.
Electroretinography (ERG):
recording of retinal electrical potentials generated by flashes of light.
Endophthalmitis:
inflammation of the intraocular contents, excluding the fibrous tunic.
Enophthalmos:
caudal recession of the eye into the orbit.
Entropion:
an inversion or turning inward of the eyelid.
Enucleation:
removal of the globe.
Epilation:
removal of hair, especially cilia.
Epiphora:
overflow of tears onto the face due to impaired drainage, excessive production, or both.
Equine Recurrent Uveitis (ERU):
recurrent anterior and/or posterior uveitis of horses with a complex and incompletely understood disease process, possibly involving infection with Leptospira spp.; moon blindness, periodic ophthalmia.