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Ophtho
Ophtho Test 1
237
Veterinary Medicine
Professional
02/26/2012

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Term
aniso
Definition
unequal
Term
blepharo
Definition
- eyelid
Term
cor
Definition
- pupil
Term
cyclo
Definition
- ciliary body
Term
dacryo
Definition
- tear lacrimation
Term
hyal
Definition
- vitreous
Term
hyp
Definition
- anterior chamber or under
Term
irido
Definition
- iris
Term
kerato
Definition
- cornea
Term
ophthalmo
Definition
- globe or eye
Term
papilla
Definition
- optic disc
Term
phaco
phako
Definition
- lens
Term
tarso
Definition
- eyelid
Term
Ablation:
Definition
removal or destruction of part of the body.
Term
Accommodation:
Definition
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.
Term
Adnexa:
Definition
accessory structures of the eye (eyelids, conjunctiva, extraocular muscles, glands of the orbit, and nasolacrimal system).
Term
Acuity:
Definition
visual ability to distinguish shapes
Term
Albinism:
Definition
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).
Term
Anisocoria:
Definition
unequal or asymmetric pupils.
Term
Ankyloblepharon:
Definition
adhesion between the eyelid margins; physiologic in kittens and puppies for the first 10-14 days of life.
Term
Anophthalmia:
Definition
complete absence of the eye; anophthalmos.
Term
Anterior chamber: (AC),
Definition
space within the eye bounded anteriorly by the cornea and posteriorly by the iris; filled with aqueous humor
Term
Anterior segment:
Definition
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.
Term
Aphakia:
Definition
absence of a lens.
Term
Aphakic crescent:
Definition
a visible crescent between the iris and lens equator due to subluxation of the lens.
Term
Aqueous flare:
Definition
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.
Term
Aqueous humor:
Definition
clear watery fluid produced by the ciliary body that occupies the anterior and posterior chambers of the eye; egresses through the iridocorneal angle.
Term
Asteroid hyalosis:
Definition
spherical and stellate calcium-lipid opacities in an otherwise normal vitreous; common in older animals
Term
Astigmatism:
Definition
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.
Term
Binocular vision:
Definition
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.
Term
Biomicroscopy:
Definition
microscopic examination of the various ocular structures in the living state, using a slit-lamp biomicroscope.
Term
Blepharitis:
Definition
inflammation of the eyelids.
Term
Blepharospasm:
Definition
spasm of the orbicularis oculi muscle resulting in eyelid closure; squinting.
Term
Bullous keratopathy:
Definition
formation of vesicles (blisters) on or in the cornea.
Term
Buphthalmos:
Definition
enlargement of the eye, as with glaucoma.
Term
Canthotomy:
Definition
incision of the canthus, often to provide surgical visualization or access.
Term
Canthus:
Definition
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.
Term
Caruncle:
Definition
a small piece of skin at the medial canthus from which hairs often protrude.
Term
Cataract:
Definition
any opacity of the lens or lens capsule, or both.
Term
Intumescent cataract –
Definition
swollen, enlarged; often seen with rapid onset diabetic cataracts.
Term
Incipient cataract
Definition
– opacity involving less than 10-15% of lens volume.
Term
Immature cataract
Definition
– cataractous change between incipient stage and complete cataract (15-90% of lens volume affected); hallmark feature is presence of tapetal reflex.
Term
Mature cataract
Definition
– opacity involving the entire lens volume (>90%), completely obscuring tapetal reflexion.
Term
Hypermature cataract
Definition
– liquefaction of lens due to proteolysis (lens resorption), resulting in reduction in lens volume, wrinkling of lens capsule, and sometimes visible tapetal reflexion.
Term
Morgagnian Cataract
Definition
– hypermature, partially liquefied cataract in which the nucleus falls ventrally.
Term
Chalazion:
Definition
lipogranuloma of a meibomian gland due to impaction of secretions.
Term
Chemosis:
Definition
conjunctival edema.
Term
“Cherry eye”:
Definition
lay term for prolapsed gland
of the third-eyelid.
Term
Chorioretinitis:
Definition
inflammation of the choroid and retina.
Term
Choroid:
Definition
posterior portion of the uvea located between the retina and sclera; furnishes nourishment to the retina and vitreous body.
Term
Ciliary body:
Definition
portion of the uveal tract between the iris and the choroid, consisting of ciliary muscles and ciliary processes that produce aqueous humor.
Term
Cilium (pleural cilia):
Definition
eyelash
Term
Collyrium:
Definition
eye wash
Term
Coloboma:
Definition
a congenital fissure or cleft of any part of the eye or eyelid. Typical coloboma is due to incomplete closure of the fetal fissure (typically at the 6 o'clock position).
Term
Conjunctiva:
Definition
mucous membrane lining
the eyelids (palpebral or nictitans conjunctiva) and covering the anterior sclera (bulbar conjunctiva).
Term
Conjunctival fornix:
Definition
the reflection of the conjunctiva from the eyelid (palpebral) to the globe (bulbar).
Term
Corectopia:
Definition
displacement of the pupil from its normal position.
Term
Cornea:
Definition
the clear, transparent anterior portion of the fibrous tunic of the eye.
Term
Corneal degeneration:
Definition
unilateral or bilateral keratitis characterized by corneal edema , mineral or lipid deposits, and sometimes neovascularization.
Term
Corneal dystrophy:
Definition
bilateral, hereditary, non-inflammatory corneal disease involving the epithelium, stroma, or endothelium
Term
Corneal reflex:
Definition
closure of the eyelids and globe retraction induced by a gentle touching of the cornea with wisps of cotton or use a corneal aesthesiometer.
Term
Cyclitis:
Definition
inflammation of the ciliary body.
Term
Corpora nigrum (granula iridica):
Definition
irregular cystic dilations on the pupillary margin of the iris in large herbivores. Most notable dorsally, but also typically present ventrally.
Term
Cyclocryotherapy:
Definition
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.
Term
Cortical blindness:
Definition
blindnes caused by a lesion in the occipital cortex.
Term
Cyclophotoablation:
Definition
similar to cyclocryotherapy, but utilizing a laser probe to destroy the ciliary body epithelium. Usually performed with a diode ophthalmic laser.
Term
Cyclodialysis:
Definition
the establishement of communication between the anterior chamber and the suprachoroidal space in order to reduce intraocular pressure.
Term
Cycloplegia:
Definition
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.
Term
Cycloplegic:
Definition
a drug that temporarily paralyzes the ciliary muscle: pupillary dilatation also results due to iris sphincter paralysis. Examples include atropine and tropicamide.
Term
Dacryoadenitis:
Definition
inflammation of the lacrimal gland or gland of the third eyelid.
Term
Dacryocystitis:
Definition
inflammation of the lacrimal sac and/or nasolacrimal duct.
Term
Dark adaptation:
Definition
the ability of the retina and pupil (iris) to adjust to decreased illumination.
Term
Dazzle reflex:
Definition
subcortical reflex in which a rapid eye blink is elicited by a bright light shone into an eye.
Term
Decussation:
Definition
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.
Term
Dermoid:
Definition
a congenital growth (choristoma) consisting of skin and its dermal appendages. Usually located near or connected to lateral canthus involving cornea, sclera, and conjunctiva.
Term
Descemetocele:
Definition
a deep corneal ulcer characterized by exposure and possible protrusion of Descemet's membrane.
Term
Descemet's membrane:
Definition
the basement membrane of the corneal endothelium. Diagram to the right.
Term
Diopter:
Definition
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.
Term
Distichiasis:
Definition
condition in which a single cilium emerges from one or more meibomian gland orifices.
Term
Districhiasis:
Definition
condition in which multiple cilia emerge from one meibomian gland orifice.
Term
Dyscoria:
Definition
abnormally shaped pupil
Term
Ectasia:
Definition
dilatation; distention; usually pertaining to cornea or sclera and resulting from acquired weakness or congenital malformation.
Term
Ectopic cilia:
Definition
cilia protruding through palpebral conjunctiva, often causing corneal ulceration and/or pain. Diagram to the right
Term
Ectropion:
Definition
an eversion or turning out of the eyelid.
Term
Ectropion uvea:
Definition
eversion of posterior iridal pigmented tissue around the pupillary margin into the anterior chamber; usually associated with anterior uveitis.
Term
Electroretinography:
Definition
(ERG), recording of retinal electrical potentials generated by flashes of light.
Term
Endophthalmitis:
Definition
inflammation of the intraocular contents, excluding the fibrous tunic.
Term
Enophthalmos:
Definition
caudal recession of the eye into the orbit.
Term
Entropion:
Definition
an inversion or turning inward of the eyelid.
Term
Enucleation:
Definition
removal of the globe.
Term
Epilation:
Definition
removal of hair, especially cilia.
Term
Epiphora:
Definition
overflow of tears onto the face due to impaired drainage, excessive production, or both.
Term
Equine Recurrent Uveitis (ERU):
Definition
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.
Term
Esotropia:
Definition
medial strabismus of one or both eyes; convergent strabismus.
Term
Euryblepharon:
Definition
large palpebral fissure, as seen in brachycephalic breeds.
Term
Evisceration:
Definition
removal of the intraocular contents, with retention of the fibrous tunic (cornea and sclera) and placement of a prosthesis within the corneoscleral shell.
Term
Exenteration:
Definition
removal of all of the orbital tissues, including the eye and its nervous, vascular, and muscular connections.
Term
Exophthalmos:
Definition
protrusion of the eyeball from its normal position in the orbit.
Term
Exotropia:
Definition
lateral strabismus of one or both eyes; divergent strabismus.
Term
Facet:
Definition
a depression in the surface of the cornea lined with epithelium.
Term
Filtration angle:
Definition
the pathway of egress of aqueous humor from the eye; iridocorneal angle
Term
Floaters:
Definition
particles in the vitreous.
Term
Fluorescein:
Definition
a water-soluble fluorescing dye which binds to glycosaminoglycans, notably within the corneal stroma. Used to detect corneal or conjunctival ulcers, patency of the nasolacrimal apparatus, and chorioretinal circulation.
Term
Fovea:
Definition
a small, thinned area of retina with increased numbers of photoreceptors providing the clearest vision; present in many primates, reptiles, and birds.
Term
Fundus:
Definition
the posterior layers of the eye, including the optic disc, retina, choroid, and sclera; visual through the pupil with an ophthalmoscope. Diagram of a generalized fundus as observed through an ophthalmoscope to the right. Significant species variation occurs
Term
Glands of Moll:
Definition
apocrine sweat glands connected with the follicles of the eyelash.
Term
Glands of Zeis:
Definition
modified sebaceous glands connected with the follicles of the eyelash.
Term
Glaucoma:
Definition
abnormal increase in intraocular pressure (IOP) above that which is compatible with normal function of the eye due to impaired aqueous humor aoutflow.Closed (narrow) angle – mechanical obstruction of the iridocorneal angle
Open angle – gonioscopically normal iridocorneal angle
Term
Gonioscopy:
Definition
examination of the iridocorneal angle, utilizing a special contact lens, magnification, and light source.
Term
Hemeralopia:
Definition
visual impairment/blindness in bright light; day blindness
Term
Heterochromia iridis:
Definition
irides or part of one iris has a different color.
Term
Hippus:
Definition
spasmodic dilation and contraction of the pupil independent of light stimulation; iridokinesia.
Term
Hordeolum;
Definition
localized, purulent infection of a gland of the eyelid.
External – infection of the glands of Moll or Zeis.
Internal – infection of the meibomian glands.
Term
Horner's syndrome:
Definition
a usually unilateral, sympathetic denervation resulting in enophthalmos, protrusion of the third eyelid, ptosis, and/or miosis in most species. Ipsilateral sweating occurs in horses.
Term
Hyalitis:
Definition
inflammation of the vitreous body, usually characterized by leukocytes, proteins, and debris; usually secondary to inflammation of adjacent structures (retina, choroid, ciliary body).
Term
Hyperopia:
Definition
a refractive error resulting in the image being focused behind the retina (farsightedness).
Term
Hypertropia:
Definition
deviation of the eyes in which one eye is higher than the other.
Term
Hyphema:
Definition
hemorrhage in the anterior chamber.
Term
Hypopyon:
Definition
suppurative exudate in the anterior chamber.
Term
Hypotony:
Definition
low intraocular pressure.
Term
Iridectomy:
Definition
surgical excision of a portion of the iris.
Term
“Injection”:
Definition
congestion of blood vessels, usually conjunctival vessels.
Term
Iridocorneal angle:
Definition
the angle between the cornea and base of the iris; drainage angle
Term
Iridocyclitis:
Definition
inflammation of the iris (iritis) and ciliary body (cyclitis); anterior uveitis.
Term
Iridodonesis:
Definition
trembling of the iris with movement of the eye, indicating loss of lens support.
Term
Iridotomy:
Definition
incision of the iris.
Term
Iris (pleural irides):
Definition
the disc-like, centrally perforated (forming the pupil), colored portion of the anterior uvea within the anterior segment of the eye.
Term
Iris bombe:
Definition
a condition in which the iris is bowed
forward by the collection of aqueous in the posterior
chamber due to complete posterior synechia.
Term
Iritis:
Definition
inflammation of the iris, marked by miosis and
discoloration.
Term
Keratectomy:
Definition
excision of part of the cornea.
Term
Keratic precipitates:
Definition
inflammatory cell and/or fibrin aggregates adhering to the corneal endothelium as a result of uveitis.
Term
Keratitis:
Definition
corneal inflammation. Often classified as ulcerative or non-ulcerative.
Term
Keratoconjunctivitis sicca:
Definition
inflammation of the cornea and conjunctiva secondary to dryness caused by impaired lacrimal gland function and decreased tear flow
Term
Keratoconus:
Definition
conical protrusion of the cornea.
Term
Keratoglobus:
Definition
globular protrusion of the cornea.
Term
Keratoplasty:
Definition
corneal grafting, either partial thickness (lamellar) or full thickness (penetrating).
Term
Keratotomy:
Definition
incision or puncture into the cornea
Term
Lacrimation:
Definition
production of precorneal tear film (tears). Diagram of the nasolacrimal system to the right.
Term
Lagophthalmos:
Definition
incomplete eyelid closure and globe coverage. Often associated with exposure keratitis.
Term
Lamina cribrosa:
Definition
fenestrated area of sclera, near the posterior pole of the globe, where optic nerve fibers exit the eye.
Term
Lens:
Definition
the transparent, biconvex body separating the posterior chamber from the vitreous of the eye; refracts rays of light so that they focus on the retina.
Term
Lenticonus:
Definition
conical projection of the anterior or posterior surface of the lens.
Term
Leukocoria:
Definition
“white pupil”; suggests cataract, nuclear sclerosis, retinal detachment, or other disease processes.
Term
Leukoma:
Definition
a dense white corneal opacity
Adherent leukoma – corneal opacity in which the iris adheres to the corneal endothelium.
Term
Limbus:
Definition
junction of the cornea, sclera, and bulbar conjunctiva.
Term
Macula:
Definition
(1) A moderate corneal opacity. (2) A cone-rich area of high visual acuity in primate and avian retinas.
Term
Megalocornea:
Definition
a congenitally large cornea.
Term
Meibomian (tarsal) glands:
Definition
modified sebaceous glands in the eyelids with openings on the eyelid margin; produce the outer oily layer of tear film.
Term
Menace response:
Definition
eyelid closure in response to a visually threatening movement.
Term
Microphthalmos:
Definition
an abnormally small globe.
Term
Miosis:
Definition
constriction of the pupil.
Term
Megalocornea:
Definition
a congenitally large cornea.
Term
Miotic:
Definition
a medication causing the pupil to constrict.
Term
Mydriasis:
Definition
dilation of the pupil
Term
Myopia:
Definition
a refractive error in which the point of focus for rays of light from distant objects is in front of the retina; nearsightedness, myopic.
Term
Nebula:
Definition
minor corneal opacity
Term
Neovascularization:
Definition
formation of new blood vessels where there were previously none (as in cornea or on face of iris).
Term
Neurotrophic keratitis:
Definition
keratitis caused by anesthesia of the cornea.
Term
Nevus:
Definition
a region of focally increased pigmentation, usually of the iris (“iris freckle”).
Term
Non-tapetal fundus:
Definition
ventral, variably pigmented portion of the fundus in animals containing a tapetum.
Term
Nyctalopia:
Definition
night blindness.
Term
Nystagmus:
Definition
an involuntary, rapid eye movement; often classified by direction.
Physiologic – oculocephalic reflex; optokinetic
Jerk – consist of fast and slow phases
Rotary – the eye partially rotates around the visual axis
Pendulous – oscillations are equal in deviation and speed; usually congenital
Term
Oculocardiac reflex:
Definition
vagally mediated decrease of heartbeat caused by pressure or traction on the eye.
Term
O.D.:
Definition
abbreviation for right eye (oculus dexter, Latin).
Term
O.S.:
Definition
abbreviation for left eye (oculus sinister, Latin).
Term
O.U.:
Definition
abbreviation for both eyes or each eye (oculus uterque, Latin).
Term
Ophthalmia neonatorum:
Definition
conjunctivitis in the newborn, especially behind closed lids of neonatal puppies and kittens with physiologic ankyloblepharon.
Term
Optic axis:
Definition
imaginary line from the center of the posterior pole of the eye through the center of the lens and cornea.
Term
Optic disc:
Definition
visible portion of the optic nerve in the fundus of the eye; optic papilla; optic nerve head
Term
Optic disc cupping:
Definition
abnormal depression in the optic disc, often associated with
glaucoma.
Term
PPM:
Definition
persistent pupillary membrane; congenital remnants of the prenatal pupillary vascular membrane that extend from the collarette region of the iris into the anterior chamber, to the cornea, or other areas of the iris, may appear as “web-like” strands stretching across the pupil. See diagram below a: iris into anterior chamber; b: iris to lens, c. iris to iris; d. iris to cornea
Term
Palpebral reflex:
Definition
eyelid closure in reaction to stimulation of the periocular skin.
Term
Pannus:
Definition
invasion of the cornea by subepithelial neovascularization and pigmentation; chronic superficial keratitis.
Term
Panophthalmitis:
Definition
inflammation involving all structures of the eye, including the neural, uveal, and fibrous tunics.
Term
Papilla:
Definition
the optic disc.
Term
Papilledema:
Definition
edema of the optic disc or papilla.
Term
Pectinate ligaments:
Definition
thin extensions of anterior uveal tissue spanning from the iris root to the inner cornea across the ididocorneal angle.
Term
Penetrating:
Definition
a wound entering an ocular structure but not going completely through it
Term
Perforating:
Definition
a wound going completely through an ocular structure.
Term
Persistent pupillary membrane:
Definition
congenital remnants of the prenatal pupillary vascular membrane that extend from the collarette region of the iris into the anterior chamber, to the cornea, or other areas of the iris, may appear as “web-like” strands stretching across the pupil. See diagram below a: iris into anterior chamber; b: iris to lens, c. iris to iris; d. iris to cornea
Term
Photophobia:
Definition
abnormal sensitivity to and discomfort from light.
Term
Photoreceptor:
Definition
a specialized neuron in the retina that converts light to an electrical stimulus; rod cells for dim light and peripheral vision, and cone cells for acuity, color vision, and bright light.
Term
Phthisis bulbi:
Definition
shrunken and atrophic globe, usually resulting from severe intraocular inflammation.
Term
Plasmoid aqueous:
Definition
proteinaceous aqueous resulting from leakage of plasma proteins into the aqueous humor across a disrupted blood-aqueous barrier. Pathognomonic for anterior uveitis.
Term
Polycoria:
Definition
more than one pupil in the iris.
Term
Posterior chamber:
Definition
aqueous humor-filled space between the posterior surface of the iris and the anterior surface of the lens.
Term
Posterior segment:
Definition
collective term for those parts of the eye posterior to the lens, including the vitreous, retina, choroid, optic disc, and sclera.
Term
Pseudopterygium:
Definition
region of the bulbar conjunctiva that advances over but does not adhere to the cornea, seen most commonly in rabbits.
Term
Pterygium:
Definition
region of bulbar conjunctiva that advances onto and adheres to the cornea.
Term
Ptosis:
Definition
drooping of the upper eyelid.
Term
Pupil:
Definition
the opening in the center of the iris.
Term
Pupillary light reflex:
Definition
Direct: constriction of the ipsilateral pupil when the retina is stimulated with light.
Indirect (Consensual): constriction of the pupil when the contralateral retina is stimulated with light; occurs as a result of decussation of the optic nerve fibers.
Term
Purkinje-Sanson Images:
Definition
Three images of the same object produced by reflections from the surface of the cornea, the anterior surface of the lens, and the posterior surface of the lens. Diagram to the right.
Term
Refraction:
Definition
deviation in the course of rays of light in passing from one transparent medium into another of different density; determination of refractive errors of the eye and correction by various lenses.
Term
Photoreceptor:
Definition
a specialized neuron in the retina that converts light to an electrical stimulus; rod cells for dim light and peripheral vision, and cone cells for acuity, color vision, and bright light.
Term
Phthisis bulbi:
Definition
shrunken and atrophic globe, usually resulting from severe intraocular inflammation.
Term
Plasmoid aqueous:
Definition
proteinaceous aqueous resulting from leakage of plasma proteins into the aqueous humor across a disrupted blood-aqueous barrier. Pathognomonic for anterior uveitis.
Term
Polycoria:
Definition
more than one pupil in the iris.
Term
Posterior chamber:
Definition
aqueous humor-filled space between the posterior surface of the iris and the anterior surface of the lens.
Term
Posterior segment:
Definition
collective term for those parts of the eye posterior to the lens, including the vitreous, retina, choroid, optic disc, and sclera.
Term
Pseudopterygium:
Definition
region of the bulbar conjunctiva that advances over but does not adhere to the cornea, seen most commonly in rabbits.
Term
Pterygium:
Definition
region of bulbar conjunctiva that advances onto and adheres to the cornea.
Term
Ptosis:
Definition
drooping of the upper eyelid.
Term
Pupil:
Definition
the opening in the center of the iris.
Term
Pupillary light reflex:
Definition
Direct: constriction of the ipsilateral pupil when the retina is stimulated with light.
Indirect (Consensual): constriction of the pupil when the contralateral retina is stimulated with light; occurs as a result of decussation of the optic nerve fibers.
Term
Purkinje-Sanson Images:
Definition
Three images of the same object produced by reflections from the surface of the cornea, the anterior surface of the lens, and the posterior surface of the lens. Diagram to the right.
Term
Refraction:
Definition
deviation in the course of rays of light in passing from one transparent medium into another of different density; determination of refractive errors of the eye and correction by various lenses.
Term
Retina:
Definition
innermost tunic of the eye, containing the neural elements for reception and transmission of visual stimuli.
Term
Retroillumination:
Definition
use of light reflected from a deeper structure to examine a more anterior structure
Term
Retropulsion:
Definition
a driving back, as in the ability to move the globe caudally into the orbit.
Term
Rose Bengal:
Definition
topical ophthalmic stain used to detect dead, degenerating, and devitalized corneal and conjunctival cells.
Term
Rubeosis irides:
Definition
neovascularization of the iris, usually associated with inflammation.
Term
Sclera:
Definition
the white part of the eye, a tough covering which forms part of the external fibrous tunic of the eye.
Term
Schirmer Tear Test:
Definition
test for tear formation in which absorbent paper is folded over the lid margin for 1 minute and the amount of wetting is measured.
Term
Strabismus:
Definition
a deviation of the eye
Term
Staphyloma:
Definition
a bulging defect (ectasia) of cornea or sclera which is lined with uveal tissue.
Term
Stars of Winslow:
Definition
end on view of small vessels penetrating the tapetum to connect deeper choroid vessels to the choriocapillaris, seen as mosaic of regularly spaced minute dark foci, used in description of the equine fundus (prominent in herbivores).
Term
Striate Keratopathy:
Definition
linear gray-blue opacities deep within the cornea caused by fractures or stretching of Descemet's membrane and development of fibrosis and edema within the crack; Haab's striae
Term
Stye:
Definition
localized, purulent infection of a gland of Zeis or Moll; external hordeolum.
Term
Symblepharon:
Definition
adhesion between the conjunctival surfaces or between the cornea and conjunctiva.
Term
Synchysis:
Definition
liquefied condition of the vitreous.
Term
Synechia (pleural synechiae):
Definition
adhesion of the iris to the cornea (anterior synechia), or the lens (posterior synechia).
Term
Syneresis:
Definition
liquefaction of the vitreous, with separation of fluid and contraction of the gel component.
Term
Tapetal reflex:
Definition
a bright reflection from the tapetum through the pupil that is detected under dark conditions in animals with a tapetum.
Term
Tapetum:
Definition
a semicircular, reflective layer of the choroid occupying the dorsal half of the fundus and providing additional retinal stimulation. Tapetum cellulosum in carnivores; Tapetum fibrosum in herbivores.
Term
Tarsorrhapy:
Definition
suturing together of the eyelids.
Term
Tenon's capsule:
Definition
a fibrous sheath enveloping the globe posterior to the limbus; fascia bulbus.
Term
Tonometry:
Definition
measurement of intraocular pressure (IOP).
Term
Transillumination:
Definition
examination of an ocular structure by use of a transversely directed beam of focal light
Term
Trichiasis:
Definition
normally positioned cilia that are directed against the cornea. Diagram to the right.
Term
Uvea:
Definition
the middle, vascular tunic of the eye consisting of iris, ciliary body and choroid. Diagram to below.
Anterior uvea - iris and ciliary body
Posterior uvea - choroid
Term
Uveitis:
Definition
inflammation of the uvea. May affect the anterior uvea (anterior uveitis, iridocyclitis), posterior uvea (posterior uveitis, chorioretinitis), or both (panuveitis)
Term
Vibrissae:
Definition
stiff tactile hairs around the face of animals.
Term
Visual field:
Definition
the area which can be seen without shifting the gaze; can apply to that of both eyes or each eye separately.
Term
Vitreous body:
Definition
the transparent gelatinous material filling the posterior portion of the globe between the lens and retina.
Term
Vitreous cavity:
Definition
space containing the vitreous body and bounded anteriorly by the posterior lens capsule and posteriorly by the retina.
Term
Zonules (zonules of Zinn):
Definition
numerous fine tissue strands (ligaments) which connect the ciliary processes to the lens equator (360 degrees) and hold the lens in place.
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