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Ophthalmology Terminology โ
Complete Study Guide
Conjunctiva (kahn-junk-TI-vuh). - โ Transparent mucous membrane covering the outer surface of the eyeball except the cornea, and lining the inner surfaces of the eyelids. Cornea (KOR-nee-uh). - โ Transparent front part of the eye that covers the iris, pupil, and anterior chamber and provides most of an eye's optical power. Sclera (SKLEH-ruh). - โ Opaque, fibrous, protective outer layer of the eye ("white of the eye") that is directly continuous with the cornea in front and with the sheath covering optic nerve behind. Hordeolum (sty, stye). - โ Acute pustular infection of the oil glands of Zeis, located in an eyelash follicle at the eyelid margin. Chalazion (kuh-LAY-zee-un). - โ Inflammed lump in a meibomian gland (in the eyelid). Inflammation usually subsides, but may need surgical removal. Sometimes called an internal hordeolum. Pinguecula (pin-GWEK-yu-luh). - โ Yellowish-brown subconjunctival elevation composed of degenerated elastic tissue; may occur on either side of the cornea. Benign. Pterygium (tur-IH-jee-um). - โ Abnormal wedge-shaped growth on the bulbar conjunctiva. May gradually advance onto the cornea and require surgical removal. Probably related to sun irritation. Ectropion (ek-TROH-pee-un). - โ Outward turning of the upper or lower eyelid so that the lid margin does not rest against the eyeball, but falls or is pulled away. Can create corneal
exposure with excessive drying, tearing, and irritation. Usually from aging. Entropion (en-TROH-pee-un). - โ Inward turning of upper or lower eyelid so that the lid margin rests against and rubs the eyeball. (and eyelashes! ouch!) Esotropia (ee-soh-TROH-pee-uh), - โ cross-eyes. Eye misalignment in which one eye deviates inward (toward nose) while the other fixates normally. Exotropia (eks-oh-TROH-pee-uh), - โ wall-eyes. Eye misalignment in which one eye deviates outward (away from nose) while the other fixates normally. Amblyopia (am-blee-OH-pee-uh), - โ "lazy eye." Decreased vision in one or both eyes without detectable anatomic damage in the eye or visual pathways. Usually uncorrectable by eyeglasses or contact lenses. Oculus Dexter (OD): - โ right eye Oculus Sinister (OS): - โ left eye Oculus Uterque (OU): - โ both eyes Myopia (mi-OH-pee-uh), - โ nearsightedness. Focusing defect in which the eye is overpowered. Light rays coming from a distant object are brought to focus in front of the retina. Hyperopia (hi-pur-OH-pee-uh), - โ farsightedness. Focusing defect in which an eye is underpowered. Thus light rays coming from a distant object strike the retina before coming to sharp focus, blurring vision. Presbyopia (prez-bee-OH-pee-uh). - โ Refractive condition in which there is a diminished power of accommodation arising from loss of elasticity of the crystalline lens, as occurs with aging. Usually becomes significant after age 45.
Age-related macular degeneration - โ (AMD, ARMD) (MAK- yu-lur). Group of conditions that include deterioration of the macula, resulting in loss of sharp central vision. Two general types: "Dry" macular degeneration - โ atrophic type - 85-90% - gradual breakdown of the light-sensitive cells in the macula and supporting tissue beneath the macula--> vision loss "Wet" macular degeneration - โ exudative/neovascular type - 10-15% - abnormal blood vessels grow underneath the retina - can leak fluid and blood which may lead to swelling and damage of the macula. Most common cause of decreased vision after age
Cataract. - โ Opacity or cloudiness of the crystalline lens, which may prevent a clear image from forming on the retina. Surgical removal of the lens may be necessary if visual loss becomes significant, with lost optical power replaced with an intraocular lens, contact lens, or aphakic spectacles. May be congenital or caused by trauma, disease, or age. Leading cause of blindness worldwide. Ptosis (TOH-sis). - โ Drooping of upper eyelid. May be congenital or caused by paralysis or weakness of the 3rd cranial nerve or sympathetic nerves, or by excessive weight of the upper lids. Strabismus (struh-BIZ-mus). - โ Eye misalignment caused by extraocular muscle imbalance: one fovea is not directed at the same object as the other. Eyelids - โ block foreign objects, help with sleep, blink to moisten meet at corners (commissures) consist of orbicularis oculi muscle & tarsal plate covered with skin outside & conjunctiva inside
tarsal glands secrete oil that reduces tear evaporation eyelashes help keep debris from the eye Lacrimal Apparatus - โ gland-ducts-punctum-canal-sac- nasolacrimal duct-inferior meatus-nostril Tears flowing across eyeball helps wash away foreign particles, help with diffusion of O2 & CO2 and contain bactericidal enzyme tunica fibrosa - โ Fibrous layer () = sclera and cornea aqueous humor - โ Serous fluid produced by ciliary body that flows from posterior chamber through pupil to anterior chamber of eye -- reabsorbed through trabecular system-->canal of Schlemm into bloodstream tunica vasculosa - โ Vascular layer () = choroid, ciliary body & iris tunica interna - โ Internal layer () = retina and optic nerve fovea centralis - โ the center of macula where most finely detailed images are seen due to packed receptor cells blind spot - โ where optic nerve exits the posterior surface of the eyeball no receptor cells are found in optic disk consensual reflex - โ photopupillary reflex -- both constrict if one eye is illuminated Pupillary constrictor - โ smooth muscle cells encircling the pupil Pupillary dilator - โ spokelike myoepithelial cells parasympathetic stimulation - โ narrows the pupil emmetropia - โ distant vision
scleritis - โ inflammation of sclera; rough surface. change in vision=referral! iritis - โ inflammation of the iris, usu blunt trauma, also related to disease processes; see cells & flare in anterior chamber synechiae - โ as seen in iritis: scar tissue adhesions between iris & lens-->irregular borders of pupil [A synechia is an eye condition where the iris adheres to either the cornea (i.e. anterior synechia) or lens (i.e. posterior synechia). Synechiae can be caused by ocular trauma, iritis or iridocyclitis and may lead to certain types of glaucoma.] hyphema - โ blood layering in anterior chamber orbital cellulitis - โ emergency! differs from periorbital: systemically ill, proptosis (most common cause in children), conjunctiva edema, hurts to move eye, loss of visual acuity REFER to opthalmology/ER if see the following: - โ Decreased Vision Ocular Pain Severe Photophobia Circumcorneal redness Corneal Edema Corneal Ulcers/Dendrites Abnormal Pupil Proptosis- forward displacement of globe Elevated IOP ametropia - โ refractive errors: optical imperfections that prevent the eye from properly focusing lightโblurred vision astigmatism - โ vision blurred at any distance. misshapen cornea results in 2+focal lines that focus in front, behind, or on the retina. Corrected with lens w/ corresponding correction
hyperopia - โ far-sightedness. image focuses behind retina. Causes--axial: eye too short; curvature: cornea not sufficiently curved. CORRECTION: move focus forward w/ convex converging lens with positive refractive power myopia - โ near-sightedness. image focuses IN FRONT OF retina. Causes-- axial myopia: eye too long; curvature myopia: cornea excessively curved. CORRECTION: move focal point further back w/ concave dispersing lens with negative refractive power presbyopia - โ difficulty with near vision ~age 40. Results from loss of lens elasticity: not a true refractive error, but a calcification; lens can't accommodate/ get as convex as it needs to be to focus near objects. No problem with the flat lens shape of distance vision. pupil with sympathetic stimulation - โ mydriasis (dilated). also cocaine pupil with parasympathetic stimulation - โ miosis (constricted). also opioids amaurosis Fugax - โ transient monocular blindness: curtain down & back up. Most from plaque or blood clot scintillating (flickering) scotoma - โ aura associated with migraine: vascular changes in visual cortex before the headache: flashing lights, squiggly lines, field cuts. [I used to not be able to see anyone's faces :)] arcus abnormality (formerly arcus senilus) - โ milky ring around eye: lipid ring. typically associated w/ dyslipidemia, especially <age 40. Lipid work up indicated Kayser Fleischer rings: - โ copper ring around iris. Copper deposition, often associated tremors, order serum ceruloplasmin, refer for chelation. Autosomal recessive dz gene, mapped to c/s 13
(seen in 34% of healthy population; fine as long as pupillary response is normal) uveitis - โ Eye inflammation affecting the middle layer of tissue in the eye wall (uvea). Warning signs often come on suddenly and get worse quickly: eye redness, pain and blurred vision. Unilateral or bilateral, primarily affects people ages 20 to 50, but it may also affect children. Can -->permanent vision loss. Dx & Tx early. Possible causes of uveitis are infection, injury, or an autoimmune or inflammatory disease. Many times a cause can't be identified. leukocoria - โ A white pupillary reflex rather than normal red. Concern for retinoblastoma, usual Dx age 12-24 mo.
