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Cataracts

Terms in this set (47)

Zone of discontinuity
alternating light and dark bands that represent zones within the nucleus, possibly due to different index of refractions
Zone of disjunction
clear or darker region seen under anterior lens capsule, consists of newest lens fibers being produced
Embryonic nucleus
dark, central space, contains primary lens fibers. Develop around 6th-7th week of gestation
Fetal nucleus
"coffee bean" shaped region on either side of embryonic nucleus. Where sutures are! Secondary fibers grow toward each other to form suture lines. Developed 8 month of gestation.
Juvenile nucleus
aka infantile nucleus, developed by early to mid-teens. Extends from end of fetal nucleus to next bright light
Adult nucleus
end of juvenile to next bright line. Developed by later teens to mid 20s
Cortex
Age determines how thick cortex layer is, formation begins around mid 20s. Young lens will be mostly nuclei, older lens is mostly cortex
Mittendorf dot
Remnant of hyaloid system, small circular white opacity on inferior nasal posterior lens capsule. Typically small w/no vision effect
Vogt's reflex line
Remnant of hyaloid system. Faint, gray reversed C-shaped line on posterior lens capsule. No effect on vision
Colobma
Incomplete lens development, typically a notch in lens edge
Ectopia lentis, lens luxation
dislocation of the lens associated with trauma, genetic syndromes, zonule weakness. Marfan's syndrome displaced upward. Homocystinuria displaced downward
Lenticonus
conical deformity with protrusion of anterior or posterior lens. Assos with Alport's syndrome and Lowe's syndrome
Microphakia
abnormally small lens
Spherophakia
short radius of curvature --> high myope
Embryonic nuclear cataracts
cgCAT: Bilateral, grainy gray axial central opacity, doesn't affect vision, dominant inheritance
Cataracta centralis pulverralenta
cgCAT: granular central opacity
Fetal cataract
cg.CAT:opacification of either anterior or posterior fetal nucleus, gray opacity, little to no effect on vision
Sutural cataract
cgCAT: sutural cataract. Typically bilateral, stellate stalagmite or coralliform in shape, good VA. "Y" suture doesn't look full
Anterior polar cataract
cgCAT: cotton ball-like opacity anterior subcapsular location. Sharply demarcated edge. Persistant pupillary membrane: remnant of the tunica vasculosa lentis, which is vascular supply of hyaloid system. Little or no effect on VA
Posterior polar cataract
cgCAT: under posterior capsule, associated with hyaloid remnant. GREATER effect on vision! b/c closer to nodal pt
Pyramidal cataract
cone or pyramid-shape opacity, involves anterior capsule and protrudes into anterior chamber, little effect on VA
Zonular of lamella cataract
cgCAT: most common congenital cataract! (40%). Usually bilateral and affects one region of the lens: one lamella or zone. Circular zone around surrounding nucleus is clear. Spokes or "riders" overlying fibers. Assoc w/ abnormal calcium metabolism, can have tooth enamel/formation anomalies
total-diffuse cataract
cgCAT: frequently inherited, all liens fibers affected, white pupillary mass - calcified`
Juvenile cataracts
present after 3 mo of age through adolescence, VA minimally affected3
Presenile cataracts
involves adult nucleus or cortex, ages 30-50yrs, premature onset of age related cataracts
Age related cataracts
associated with oxidative stress, protein oxidative modifications, risk factors: aging, smoking, corticosteroids, diabetes, nutrition, UV
Cortical Cataracts
hydration and swelling of cortex due to increased permeability of lens capsule, liquifaction of lens fibers. Considered "soft" cataract because of fluids. Contains vacuoles, water clefts, spokes, lemellar separation, photoxic, phacotoxic, phagcolytic algucoma, pacomorphic glaucoma
Symptoms of cortical cataracts
glare, decrease acuity, decreased contrast, monocular diploplia, minimal increase in hyperopia refraction
Photoxic-phacoanaphylactic changes
escape of lenticular amino acid proteins into aqueous through intact but permeable capsule
Phagcolytic glaucoma
proteins and macrophages in TM impede aqueous outflow and elevate IOP
phacomorphic glaucoma
swelling of cortex increases lens size, shallows anterior chamber with opposition of posterior iris to anterior lens capsule with iris bombe and angle closure + secondary angle glaucoma
Nuclear cataract - nuclear sclerosis (NS)
most common type! "hard" cataract. newly formed lens fibers push and compress old fibers towards center oflens, results of sclerosis of fibers. Myopic shift -0.15-15D.
Urochrome
pigment that accounts for yellow-gold to dark brown color in advanced nuclear sclerosis. mature when entire nucleus is brown (brunescent)
Symptoms of nuclear sclerosis
distance blur, improved near "second sight", myopic shift, need for greater light, loss of color discrimination, monocular diplopia
Morgagnian cataract
solid "hard" nucleus floating within liquefied white cortex
Posterios subcapsular cataracts
PSC: decrease in visual acuity especially in bright light of near work
Cupuliform
PSC: most common form of PSC. cup or saucer shape, granular opacification under PSC region, doesn't extend into cortex. Faint iridescent blue, green color
Complicated PSC
associated with intraocular disease: retinitis pigmentosa, myopic degeneration, posterior uveitis. There is opacification in posterior subcapsular region and into adjacent cortex. Poly chromatic blue,green, and red colors are characteristic
Traumatic cataract
consider trauma if unilateral cataract! "stellate" or "rosette" flower shape. Associated with blunt ocular trauma, concussion, electric shock. If lens touched, then rapid opacification occurs.
Vossius ring
pseudocataract: pigment from iris imprints on anterior lens capsule
Epicapsular stars
pseudocataract: remnant of hyaloid system associated with persistent pupillary membrane
Pseudoexfoliation
pseudocataract: basement membrane abnomality of epithelial cells of eye. amyloid-like fibrillar material on lens capsule, high risk of glaucoma
Coronary cataract
crown-shaped opacifications. arranged in radial distribution around and over periphery of adult nucleus or cortex. Flecks
Cerulean (blue dot) cataract
bluish punctate opacitices within the adult nucleus
Diabetic cataract
white punctate or "snowflake-like" opacities within ant. or post. subcapsular regions
Glaucomflechen cataract
gray flecks in anterior subcapsular region, associated with episodes of rapid high increase in IOP >50mmhg
crystalline cataract
multicolored crystalline like opacities within the adult nucleus or cortex, unknown etiology
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