Glossary Flashcards
(235 cards)
1
Q
Ansio -
A
unequal
2
Q
Blepharo -
A
eyelid
3
Q
Cor -
A
pupil
4
Q
Cyclo -
A
ciliary body
5
Q
Dacryo -
A
tear lacrimation
6
Q
Hyal -
A
vitreous
7
Q
Hyp -
A
anterior chamber or under
8
Q
Irido -
A
iris
9
Q
Kerato -
A
cornea
10
Q
ophthalmo-
A
globe or eye
11
Q
Papilla-
A
optic disc
12
Q
Phaco-
A
lens
13
Q
Phako-
A
lens
14
Q
Tarso-
A
eyelid
15
Q
Ablation:
A
removal or destruction of part of the body.
16
Q
Accomidation:
A
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.
17
Q
Acuity:
A
visual ability to distinguish shapes
18
Q
Adnexa:
A
accessory structures of the eye (eyelids, conjunctiva, extraocular muscles, glands of the orbit, and nasolacrimal system).
19
Q
Albinism:
A
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).
20
Q
Anisocoria:
A
unequal or asymmetric pupils.
21
Q
Ankyloblepharon:
A
adhesion between the eyelid margins; physiologic in kittens and puppies for the first 10-14 days of life.
22
Q
Anophthalmia:
A
complete absence of the eye; anophthalmos.
23
Q
Anterior chamber:
A
space within the eye bounded anteriorly by the cornea and posteriorly by the iris; filled with aqueous humor.
24
Q
Anterior segment:
A
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.
25
Aphakia:
absence of a lens.
26
Aphakic crescent:
a visible crescent between the iris and lens equator due to subluxation of the lens.
27
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.
28
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.
29
Asteroid hyalosis:
spherical and stellate calcium-lipid opacities in an otherwise normal vitreous; common in older animals
30
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.
31
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.
32
Biomicroscopy:
microscopic examination of the various ocular structures in the living state, using a slit-lamp biomicroscope.
33
Blepharitis:
inflammation of the eyelids.
34
Blepharospasm:
spasm of the orbicularis oculi muscle resulting in eyelid closure; squinting.
35
Bullous keratopathy:
formation of vesicles (blisters) on or in the cornea.
36
Buphthalmos:
enlargement of the eye, due to glaucoma.
37
Canthotomy:
incision of the canthus, often to provide surgical visualization or access.
38
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.
39
Caruncle:
a small piece of normal skin at the medial canthus from which hairs often protrude.
40
Cataract:
any opacity of the lens or lens capsule, or both.
41
Intumescent cataract:
swollen, enlarged; often seen with rapid onset diabetic cataracts.
42
Incipient cataract:
opacity involving less than 10-15% of lens volume.
43
Immature cataract:
cataractous change between incipient stage and complete cataract (15-99% of lens volume affected); hallmark feature is presence of tapetal reflex.
44
Mature cataract:
opacity involving the entire lens volume (100%), completely obscuring tapetal reflection.
45
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.
46
Morgagnian cataract:
hypermature, partially liquefied cataract in which the nucleus falls ventrally.
47
Chalazion:
lipogranuloma of a meibomian gland due to impaction of secretions.
48
Chemosis:
conjunctival edema.
49
“Cherry eye”:
lay term for prolapsed gland of the third eyelid. Diagram to the right
50
Chorioretinitis:
inflammation of the choroid and retina.
51
Choroid:
posterior portion of the uvea located between the retina and sclera; furnishes nourishment to the retina and vitreous body.
52
Ciliary body:
portion of the uveal tract between the iris and the choroid, consisting of ciliary muscles and ciliary processes that produce aqueous humor.
53
Cilium (pleural cilia):
eyelash
54
Collyrium:
eye wash
55
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.
56
Conjunctiva:
mucous membrane lining the eyelids (palpebral or third eyelid conjunctiva) and covering the anterior sclera (bulbar conjunctiva).
57
Conjunctival fornix:
the reflection of the conjunctiva from the eyelid (palpebral) to the globe (bulbar).
58
Corectopia:
displacement of the pupil from its normal position.
59
Cornea:
the clear, transparent anterior portion of the fibrous tunic of the eye.
60
Corneal degeneration:
unilateral or bilateral keratitis characterized by corneal edema, mineral or lipid deposits, and sometimes neovascularization.
61
Corneal dystrophy:
bilateral, hereditary, non-inflammatory corneal disease involving the epithelium, stroma, or endothelium.
62
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.
63
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.
64
Cortical blindness:
blindness caused by a lesion in the occipital cortex.
65
Cyclitis:
inflammation of the ciliary body.
66
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.
67
Cyclophotocoagulation:
similar to cyclocryotherapy but utilizing a laser probe to destroy the ciliary body epithelium. Usually performed with a diode ophthalmic laser.
68
Cyclodialysis:
the establishment of communication between the anterior chamber and the suprachoroidal space to reduce intraocular pressure.
69
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.
70
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.
71
Dacryoadenitis:
inflammation of the lacrimal gland or gland of the third eyelid.
72
Dacryocystitis:
inflammation of the lacrimal sac and/or nasolacrimal duct.
73
Dark adaptation:
the ability of the retina and pupil (iris) to adjust to decreased illumination.
74
Dazzle reflex:
subcortical reflex in which a rapid eye blink is elicited by a bright light shone into an eye.
75
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.
76
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.
77
Descemetocele:
a deep corneal ulcer characterized by exposure and possible protrusion of Descemet's membrane.
78
Descemet's membrane:
the basement membrane of the corneal endothelium.
79
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.
80
Distichiasis:
condition in which a single cilium emerges from one or more meibomian gland orifices.
81
Districhiasis:
condition in which multiple cilia emerge from one meibomian gland orifice.
82
Dyscoria:
abnormally shaped pupil.
83
Ectasia:
dilatation; distention; usually pertaining to cornea or sclera and resulting from acquired weakness or congenital malformation.
84
Ectopic cilia:
cilia protruding through palpebral conjunctiva, often causing corneal ulceration and/or pain.
85
Ectropion:
an eversion or turning out of the eyelid.
86
Ectropion uvea:
eversion of posterior iridal pigmented tissue around the pupillary margin into the anterior chamber; usually associated with anterior uveitis.
87
Electroretinography (ERG):
recording of retinal electrical potentials generated by flashes of light.
88
Endophthalmitis:
inflammation of the intraocular contents, excluding the fibrous tunic.
89
Enophthalmos:
caudal recession of the eye into the orbit.
90
Entropion:
an inversion or turning inward of the eyelid.
91
Enucleation:
removal of the globe.
92
Epilation:
removal of hair, especially cilia.
93
Epiphora:
overflow of tears onto the face due to impaired drainage, excessive production, or both.
94
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.
95
Esotropia:
medial strabismus of one or both eyes; convergent strabismus.
96
Euryblepharon:
large palpebral fissure, as seen in brachycephalic breeds.
97
Evisceration:
removal of the intraocular contents, with retention of the fibrous tunic (cornea and sclera) and placement of a prosthesis within the corneoscleral shell.
98
Exenteration:
removal of all of the orbital tissues, including the eye and its nervous, vascular, and muscular connections.
99
Exophthalmos:
protrusion of the eyeball from its normal position in the orbit.
100
Exotropia:
lateral strabismus of one or both eyes; divergent strabismus.
101
Facet:
a depression in the surface of the cornea lined with epithelium.
102
Filtration angle:
the pathway of egress of aqueous humor from the eye; iridocorneal angle
103
Floaters:
particles in the vitreous.
104
Fluorescein:
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 aqueous humor leakage.
105
Fovea:
a small, thinned area of retina with increased numbers of photoreceptors providing the clearest vision; present in many primates, reptiles, and birds.
106
Fundus:
the posterior layers of the eye, including the optic disc, retina, choroid, and sclera; visual through the pupil with an ophthalmoscope.
107
Glands of Moll:
apocrine sweat glands connected with the follicles of the eyelash.
108
Glands of Zeis:
modified sebaceous glands connected with the follicles of the eyelash.
109
Glaucoma:
abnormal increase in intraocular pressure (IOP) above that which is compatible with normal function of the eye due to impaired aqueous humor outflow.
Closed (narrow) angle – mechanical obstruction of the iridocorneal angle
Open angle – gonioscopically normal iridocorneal angle
110
Gonioscopy:
examination of the iridocorneal angle, utilizing a special contact lens, magnification, and light source. Diagram to the right
111
Hemeralopia:
visual impairment/blindness in bright light; day blindness
112
Heterochromia iridis:
irides or part of one iris has a different color.
113
Hippus:
spasmodic dilation and contraction of the pupil independent of light stimulation; iridokinesia.
114
Hordeolum:
localized, purulent infection of a gland of the eyelid.
115
External hordeolum:
infection of the glands of Moll or Zeis.
116
Internal hordeolum:
infection of the meibomian glands.
117
Horner's syndrome:
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.
118
Hyalitis:
inflammation of the vitreous body, usually characterized by leukocytes, proteins, and debris; usually secondary to inflammation of adjacent structures (retina, choroid, ciliary body).
119
Hyperopia:
a refractive error resulting in the image being focused behind the retina (farsightedness).
120
Hypertropia:
deviation of the eyes in which one eye is higher than the other.
121
Hyphema:
hemorrhage in the anterior chamber.
122
Hypopyon:
suppurative exudate in the anterior chamber.
123
Hypotony:
low intraocular pressure.
124
“Injection”:
congestion of blood vessels, usually conjunctival vessels.
125
Iridocorneal angle:
the angle between the cornea and base of the iris; drainage angle
126
Iridectomy:
surgical excision of a portion of the iris.
127
Iridocyclitis:
inflammation of the iris (iritis) and ciliary body (cyclitis); anterior uveitis.
128
Iridodonesis:
trembling of the iris with movement of the eye, indicating loss of lens support.
129
Iridotomy:
incision of the iris.
130
Iris (pleural irides):
the disc-like, centrally perforated (forming the pupil), colored portion of the anterior uvea within the anterior segment of the eye.
131
Iris bombe:
a condition in which the iris is bowed
forward by the collection of aqueous in the posterior
chamber due to complete circumferential posterior synechia.
132
Iritis:
inflammation of the iris, marked by miosis and discoloration.
133
Keratectomy:
excision of part of the cornea.
134
Keratic precipitates:
inflammatory cell and/or fibrin aggregates adhering to the corneal endothelium as a result of uveitis.
135
Keratitis:
corneal inflammation. Often classified as ulcerative or non-ulcerative.
136
Keratoconjunctivitis sicca:
inflammation of the cornea and conjunctiva secondary to dryness caused by impaired lacrimal gland function and decreased tear flow.
137
Keratoconus:
conical protrusion of the cornea
138
Keratoglobus:
globular protrusion of the cornea.
139
Keratoplasty:
corneal grafting, either partial thickness (lamellar) or full thickness (penetrating).
140
Keratotomy:
incision or puncture into the cornea
141
Lacrimation:
production of precorneal tear film (tears).
142
Lagophthalmos:
incomplete eyelid closure and globe coverage; often associated with exposure keratitis.
143
Lamina cribrosa:
fenestrated area of sclera, near the posterior pole of the globe, where optic nerve fibers exit the eye.
144
Lens:
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.
145
Lenticonus:
conical projection of the anterior or posterior surface of the lens.
146
Leukocoria:
“white pupil”; suggests cataract, nuclear sclerosis, retinal detachment, or other disease processes.
147
Leukoma:
a dense white corneal opacity
148
Adherent leukoma:
corneal opacity with iris adherent to the corneal endothelium.
149
Limbus:
junction of the cornea, sclera, and bulbar conjunctiva.
150
Macula:
(1) A moderate corneal opacity. (2) A cone-rich area of high visual acuity in primate and avian retinas.
151
Megalocornea:
a congenitally large cornea.
152
Meibomian (tarsal) glands:
modified sebaceous glands in the eyelids with openings on the eyelid margin; produce the outer oily layer of tear film.
153
Menace response:
eyelid closure in response to a visually threatening movement.
154
Microphthalmos:
an abnormally small globe.
155
Miosis:
constriction of the pupil.
156
Miotic:
a medication causing the pupil to constrict.
157
Mydriasis:
dilation of the pupil.
158
Mydriatic:
a medication causing the pupil to dilate.
159
Myopia:
a refractive error in which the point of focus for rays of light from distant objects is in front of the retina; nearsightedness, myopic.
160
Nebula:
minor corneal opacity
161
Neovascularization:
formation of new blood vessels where there were previously none (as in cornea or on surface of iris).
162
Neurotrophic keratitis:
keratitis caused by anesthesia of the cornea.
163
Nevus:
a region of focally increased pigmentation, usually of the iris (“iris freckle”).
164
Non-tapetal fundus:
ventral, variably pigmented portion of the fundus in animals containing a tapetum.
165
Nyctalopia:
night blindness.
166
Nystagmus:
an involuntary, rapid eye movement; often classified by direction.
167
Physiologic nystagmus:
oculocephalic reflex; optokinetic
168
Jerk nystagmus:
consist of fast and slow phases
169
Rotary nystagmus:
the eye partially rotates around the visual axis
170
Pendulous nystagmus:
oscillations are equal in deviation and speed; usually congenital
171
Oculocardiac reflex:
vagally mediated decrease of heartbeat caused by pressure or traction on the eye.
172
O.D.:
abbreviation for right eye (oculus dexter, Latin).
173
O.S.:
abbreviation for left eye (oculus sinister, Latin).
174
O.U.:
abbreviation for both eyes or each eye (oculus uterque, Latin).
175
Ophthalmia neonatorum:
conjunctivitis in the newborn, especially behind closed lids of neonatal puppies and kittens with physiologic ankyloblepharon.
176
Optic axis:
imaginary line from the center of the posterior pole of the eye through the center of the lens and cornea.
177
Optic disc:
visible portion of the optic nerve in the fundus of the eye; optic papilla; optic nerve head
178
Optic disc cupping:
abnormal depression in the optic disc, often associated with glaucoma
179
Palpebral reflex:
eyelid closure in reaction to stimulation of the periocular skin.
180
Pannus:
invasion of the cornea by subepithelial neovascularization and pigmentation; chronic superficial keratitis.
181
Panophthalmitis:
inflammation involving all structures of the eye, including the neural, uveal, and fibrous tunics.
182
Papilla:
the optic disc.
183
Papilledema:
edema of the optic disc or papilla.
184
Pectinate ligaments:
thin extensions of anterior uveal tissue spanning from the iris root to the inner cornea across the iridocorneal angle.
185
Penetrating:
wound entering an ocular structure but not going completely through it.
186
Perforating:
a wound going completely through an ocular structure.
187
Persistent pupillary membrane (PPM):
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.
188
Photophobia:
abnormal sensitivity to and discomfort from light.
189
Photoreceptor:
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.
190
Phthisis bulbi:
shrunken and atrophic globe, usually resulting from severe intraocular inflammation.
191
Plasmoid aqueous:
proteinaceous aqueous resulting from leakage of plasma proteins into the aqueous humor across a disrupted blood-aqueous barrier. Pathognomonic for anterior uveitis.
192
Polycoria:
more than one pupil in the iris.
193
Posterior chamber:
aqueous humor-filled space between the posterior surface of the iris and the anterior surface of the lens.
194
Posterior segment:
collective term for those parts of the eye posterior to the lens, including the vitreous, retina, choroid, optic disc, and sclera.
195
Proptosis:
forward displacement of the globe such that the globe equator protrudes beyond the eyelid margins, usually resulting from trauma.
196
Pseudopterygium:
region of the bulbar conjunctiva that advances over but does not adhere to the cornea, seen most in rabbits.
197
Pterygium:
region of bulbar conjunctiva that advances onto and adheres to the cornea.
198
Ptosis:
drooping of the upper eyelid.
199
Pupil:
the opening in the center of the iris.
200
Direct pupillary light reflex:
constriction of the ipsilateral pupil when the retina is stimulated with light.
201
Indirect (Consensual) pupillary light reflex:
constriction of the pupil when the contralateral retina is stimulated with light; occurs because of decussation of the optic nerve fibers.
202
Purkinje-Sanson Images:
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.
203
Refraction:
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.
204
Retina:
innermost tunic of the eye, containing the neural elements for reception and transmission of visual stimuli.
205
Retroillumination:
use of light reflected from a deeper structure to examine a more anterior structure.
206
Retropulsion:
a driving back, as in the ability to move the globe caudally into the orbit.
207
Rose Bengal:
topical ophthalmic stain used to detect dead, degenerating, and devitalized corneal and conjunctival cells.
208
Rubeosis irides:
neovascularization of the iris; usually associated with inflammation.
209
Sclera:
the white part of the eye, a tough covering which forms part of the external fibrous tunic of the eye.
210
Schirmer Tear Test:
test for aqueous tear formation in which absorbent paper is folded over the lid margin for 1 minute and the amount of wetting is measured.
211
Strabismus:
a deviation of the eye
212
Staphyloma:
a bulging defect (ectasia) of cornea or sclera which is lined with uveal tissue.
213
Stars of Winslow:
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).
214
Striate keratopathy:
: 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.
215
Stye:
localized, purulent infection of a gland of Zeis or Moll; external hordeolum.
216
Symblepharon:
adhesion between the conjunctival surfaces or between the cornea and conjunctiva.
217
Synchysis:
liquefied condition of the vitreous.
218
Synechia (pleural synechiae):
adhesion of the iris to the cornea (anterior synechia), or the lens (posterior synechia).
219
Syneresis:
liquefaction of the vitreous, with separation of fluid and contraction of the gel component.
220
Tapetal reflex:
a bright reflection from the tapetum through the pupil that is detected under dark conditions in animals with a tapetum.
221
Tapetum:
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.
222
Tarsorrhaphy:
suturing together of the eyelids.
223
Tenon's capsule:
a fibrous sheath enveloping the globe posterior to the limbus; fascia bulbus.
224
Tonometry:
measurement of intraocular pressure (IOP).
225
Transillumination:
examination of an ocular structure by use of a transversely directed beam of focal light.
226
Trichiasis:
normally positioned cilia that are abnormally directed against the cornea.
227
Uvea:
the middle, vascular tunic of the eye consisting of iris, ciliary body and choroid.
228
Anterior uvea:
iris and ciliary body
229
Posterior uvea:
choroid
230
Uveitis:
inflammation of the uvea. May affect the anterior uvea (anterior uveitis, iridocyclitis), posterior uvea (posterior uveitis, chorioretinitis), or both (panuveitis)
231
Vibrissae:
stiff tactile hairs around the face of animals
232
Visual field:
the area which can be seen without shifting the gaze; can apply to that of both eyes or each eye separately.
233
Vitreous body:
the transparent gelatinous material filling the posterior portion of the globe between the lens and retina.
234
Vitreous cavity:
space containing the vitreous body and bounded anteriorly by the posterior lens capsule and posteriorly by the retina.
235
Zonules (zonules of Zinn):
numerous fine tissue strands (ligaments) which connect the ciliary processes to the lens equator (360 degrees) and hold the lens in place.
