8 - Cornea2 Flashcards
List names for EBMD
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ABMD
Cogan’s microcystic dystophy
Corneal dystrophies
- anterior
- stromal
- endo
A: EBMD, Reis-Buckler, Meesman
S: macular, granular, lattice, schnyder
E: Fuch’s, PPMD
EBMD
- who
- pathophys
Most common ant corneal dyst
AD, slightly more common in females
EXCESSIVE BASEMENT MEMBRANE production -> maturing epi cells become trapped beneath basement membr
EBMD
-signs/symp
Signs: negative staining - best seen with retro
Symp: typically asymptomatic + not progressive; vision loss, pain, or photophobia from central corneal changes or RCEs
Meesman’s dystrophy
- who
- signs/symp
Rare, AD, 1st year of life
Signs: extensive (hundreds), bilateral, clear INTRAEPITHELIAL cysts - diffusely spread across entire cornea (esp intrapalpebral)
Symp: often asymptomatic
-may occur from ruptured cysts or RCEs (both unlikely before mid-age)
Reis-Buckler dystrophy
- who
- pathophys
Rare, AD, early in life
Abnormal development + replacement of BOWMANS LAYER with collagen
Reis-Buckler dystrophy
-signs/symp
Signs: bilateral, symmetric, SUB-EPITHELIAL GRAY reticular opacities, most concentrated in central cornea, opacities get worse with age
Symp: PAINFUL episodes from RCEs, fewer episodes with age
Macular dystrophy
- who
- signs/symp
Rare, AR***
LEAST COMMON, MOST SEVERE stromal dystrophy
-affects VA much earlier
Signs: diffuse, superficial, central stromal haze between 3-9yo
-progression: diffuse stromal opacification, thinning, MUCOPOLYSACCHARIDE DEPOSITS (gray-white opacities with irreg borders, present in all layers)
Symp: progressive vision loss - severe by age 20-30, episodes of irritation + photophobia secondary to RCEs
Granular dystrophy
- who
- signs/symp
AD, 1st decade, no vision loss until mid-age
HYALINE DEPOSITS (small snowflake granules in central stroma)
-eventually spread toward epi + deep stroma, becoming confluent -> decr vision
RCEs are rare
Avellino dystrophy
aka granular-lattice dystophy
Rare variant of granular dystrophy
Granular + lattice-like deposits in central stroma
Lattice dystrophy
- who
- signs/symp
AD
AMYLOID DEPOSITS: anterior stromal haze with branching, refractile, lattice-like lines
Decr VA in 3rd decade from significant corneal scarring/haze
RCEs are common
TGFB1 gene
Granular, Lattice, and Avellino dystrophies result as a mutation of it
Transforming Growth Factor Beta 1(aka BIGH3) gene
Schnyder’s dystrophy
- who
- pathophys
- signs/symp
Very rare AD dystrophy
Strong assoc with HYPERLIPIDEMIA, XANTHELASMA, corneal arcus
FINE YELLOW-WHITE RING OF STROMAL CRYSTALS with CENTRAL STROMAL HAZE
Typically asymptomatic + non-progressive
Fuchs endothelial dystrophy
- who
- pathophys
AD, females, 60yo (postmenopausal)
30% have positive family hx
DESCEMET’S posterior lamina is produced in EXCESS -> guttata (clumps) of basement membrane with associated DECR IN ENDO CELL DENSITY
-Fuchs is an absolute contraindication for cataract surgery
Dystrophies with too much (2)
EBMD = too much basement membrane
Fuchs = too much descemets
Fuchs endothelial dystrophy
-signs/symp
Signs: often apparent early (30-40’s), DECR ENDO CELL DENSITY assoc with pleomorphism (change in shape) + polymegathism (change in size)
-guttata have “beaten metal” app + thick pachymetry findings
-primary concern: STROMAL EDEMA due to pumps no longer maintaining proper osmotic balance (endo cells <500 cells/mm^2) -> spills over into epi = PAINFUL BULLAE and scarring
—problems with endo -> stroma -> epi
Symp: asymptomatic until later (50-60’s), progression to blurred hazy vision that’s WORSE IN THE MORNING with pain and glare
Endothelial cell counts
- birth/children
- age 80
- when we’re concerned/problems occur
3,000 cells/mm^2
1,000-2,000
<500
(“minimum 400-700 required to prevent corneal edema”)
Posterior polymorphous dystrophy
- who
- signs/symp
AD, occurs 2nd-3rd decade, although may manifest as a cloudy cornea at birth (rare)
Signs: bilateral, asymmetric findings at level of descemet’s + endo
- subtle patches of “STUCK ON” VESICLES (hallmark), band lesions (TRAIN TRACK LESIONS), and diffuse opacities
- severe cases: corneal edema and bullae -> painful vision loss
Symp: slowly or non-progressive, most ASYMPTOMATIC; decr vision secondary to edema is most common symptom
Posterior polymorphous dystrophy
-pathophys
Metaplasia of endo cells => epithelial-like endothelim
-potential to spread over iris + angle -> seconday angle-closure glauc (15%) from PAS
Megalocornea
- who
- what
- associated issues + conditions
Rare, X-LINKED, males
Bilateral, horiz diameter 13+mm
Likely HIGHLY MYOPIC with steep corneas, good vision with correction
Stretching of ocular tissue -> lens subluxation, angle abnorm
Marfan’s, Ehlers-Danlos, Osteogenesis Imperfecta
Microcornea
- who
- what
Very rare AD or AR, uni or bilateral
Horiz diam <10mm
Usually HYPEROPIC, at risk for angle-closure glaucoma due to shallow anterior chamber
Cornea plana
- who
- pathophys
- signs
Rare, AD or AR
Corneal curvature = scleral curvature
ASSOCIATIONS: sclerocornea*, microcornea
*80% of sclerocornea cases are assoc with cornea plana; results from bilateral scleralizaton (opacification + vascularization) of cornea
Bilateral flat corneas <38D, often as low as 20-30D
Hyperopia, shallow anterior chamber, incr risk angle closure glaucoma (same as microcornea)
Aniridia
- who
- ocular manifestations
Rare, bilateral, AD
Corneal lesions (opacity, microcornea, pannus) Lenticular changes (ct, subluxation) Posterior seg abnorm (glaucoma 75%, foveal/disc hypoplasia, choroidal coloboma)
Haab’s striae
- who
- what
CONGENITAL GLAUCOMA
Horizontal cracks in descemet’s from incr IOP
vs vertical cracks from forceps birth
Axenfeld-Rieger syndrome
-characteristics
Continuum of disorders
Anterior seg developmental abnormalities that affect the AC angle
~50% develop glaucoma
Axenfeld-Rieger syndrome
-signs/symp
Posterior embryotoxin: anteriorly displaced Schwalbe’s
-up to 15% of normal eyes, no incr risk for glauc
Axenfeld anomaly: PE + angle abnorm (prominent iris processes)
-incr glauc risk
Reiger anomaly: AA + iris stromal abnorm (corectopia, hypoplasia -> holes in iris tissue (polycoria))
Reiger syndrome: RA + systemic abnorm (mental retardation, dental/craniofacial/genitourinary/skeletal abnorm)
Peter’s anomaly
Rare Born with central white corneal opacities (leukoma) with iris adhesions 80% bilateral 50-70% develop glauc May develop corneal edema, cataracts