Corneal Dystrophy Flashcards
what is a dystrophy?
developmental, symmetric and frequently hereditary changes occurring in original corneal tissue because of faulty nutrition, unrelated to other systemic or local diseases
are corneal dystrophies typically autosomal dominant or recessive?
dominant - recessive are usually more serious (morbid)
what are some standard characteristics of corneal dystrophies?
autosomal dominant, onset by age 20, bilateral, slowly progressive changes, no systemic disease association, no primary ocular disease history, centrally located, primary involvement of single corneal layer
which dystrophy is an exception to the characteristic of being discovered by age 20?
Fuch’s dystrophy (age-related degenerative process)
what are 3 anterior corneal dystrophies?
cogan microcystic, meesman’s, ries-buckler’s
what are 5 stromal corneal dystrophies?
lattice, granular/avellino, macular, schnyder’s, fleck
what are 2 posterior corneal dystrophies?
Fuch’s and posterior polymorphous
what is cogan microcystic (EBMD, ABMD) or “map-dot-fingerprint”?
epithelial basement membrane dystrophy - most common corneal dystrophy asymptomatic to irritation upon waking, transient VA, photophobia, glare, pain (RCE)
who typically gets cogan microcystic dystrophy?
non-hereditary = against the rule
40-70 y/o
male = females
what are the 4 different presentations for cogan microcystic dystrophy?
dots, microcysts, fingerprints (least common) and maps (most common)
what causes cogan microcystic dystrophy?
abnormal basement membrane (lacking hemidesmosomes) and abnormal attachment of BM to bowmans
what is the dot pathology for EBDM?
microcyst filled with cytoplasmic debris - trapped by extra BM material (BM becomes thickened in places and cysts become enveloped)
what is the treatment for acute EBMD?
abrasion protocol = bandage CL, pressure patch, antibiotic, NSAID, cycloplegic, doxycycline lubricants
what is the treatment for chronic EBMD?
abrasion protocol = bandage CL, pressure patch, antibiotic, NSAID, cycloplegic, doxycycline, lubricatns hypertonic = 5% NaCl gtt, ung (Muro 128)
what is Meesman’s dystrophy?
rare - intraepithelial cysts (6 months) = abnormal basal cells and maturation to squamous, thick BM
what happens if the cysts in Meesman’s dystrophy rupture?
pain, tearing, photophobia vision minimally affected
what is Reis-Buckler’s dystrophy?
rare - painful RCE age 5-20 with decreasing episodes by 30
bowman’s/anterior stroma replaced by fibrocellular tissue, irregular corneal surface, scarring, decrease/fluctuation in VA
what is lattice dystrophy (type 1)?
age 2-10, VA reduction, RCE common anterior stromal “inter-lacing” filamentous lesions, white spots, central haze (amyloid deposits)
what is lattice type 2 dystrophy?
similar phenotype but not genotype to type 1 central cornea sparing and associated with other conditions (VN7 palsy, peripheral neuropathy, amyloidosis)
what is granular dystrophy?
*earliest seen dystrophy - in first decade VA reduction > 40 y/o centrally discrete focal white deposits all stromal depths “cornflakes”, area between lesions is clear (deposits are hyaline-like material) RCE is rare
what is Avellino (granular type 2) dystrophy?
unique to area of italy - features are similar to lattice and granular
what is macular dystrophy?
most severe and least common dystrophy - VA reduction starts in teens, photophobia, RCE less than lattice exception to “dystrophy rule” - AR extends to periphery
what causes macular dystrophy?
(autosomal recessive disease) excess glycosaminoglycans - abnormal keratocytes storage mucopolysaccharide
what does macular dystrophy look like?
diffuse, “ground-glass” haze lesions, corneal haze between lesions, gray/white or milky/white opacities throughout stroma and limbus to limbus
what is schnyder’s central crystalline?
exception to “dystrophy rule” - associated with systemic hypercholesterolemia (cardiovascular risks)
what are the symptoms of schnyder’s central crystalline dystrophy?
mild VA reduction (20/40), no RCE, central crystals from annulus during 1st to 2nd decades, dense arcus ring
what is fleck dystrophy?
gray/white opacities, odd shaped, incidental findings at all levels of the stroma
what is posterior polymorphous dystrophy (PPD)?
asymptomatic, rare reduction in VA, polymorphous opacities at level of Descemet’s, maybe corneal edema
which dystrophy has a glaucoma risk?
posterior polymorphous dystrophy (PPD) - 15% may develop increased IOP (abnormal endothelium grows across TM onto iris = anterior synechiae)
why is Fuch’s dystrophy an exception to the “dystrophy rule”?
exceptions to rule = higher in females (postmenopausal), age-related (>40), may extend to periphery and appears multi-layered
what causes Fuch’s dystrophy?
progressive corneal disease in which corneal edema results from primary metabolic incompetence of endothelial cells - endothelial barrier and pump fail
what are the symptoms for Fuch’s dystrophy?
VA reduction in advancing cases and RCE
what are some objective clinical features in Fuch’s dystrophy?
Guttata, stroma edema, and epithelial edema
how can you evaluate the corneal thickness in Fuch’s?
stromal and epithelial edema occur with breakdown of the endothelial barrier and pump = use pachymetry (stromal edema)
how do you know if your patient has guttata or fuch’s?
some guttata = normal endothelial aging
slowly progressive fuchs = increasing number of guttata with corneal edema
what does stromal edema look like?
hazy in appearance, folds in Descemet’s and bullous keratopathy
what is the treatment for Fuch’s dystrophy?
lubricants, hypertonics (5% gtt or ung) NaCl, RCE/abrasion protocol, keratoplasty
what is congenital hereditary endothelial dystrophy?
not typical dystrophy = autosomal recessive, present at birth or 1st decade, no guttata, diffuse stromal edema and poor results with keratoplasty
when are the onset of deposits, onset of symptoms, and reduced VA with granular dystrophies?
deposits = 1st decade
symptoms = 3rd decade
asymptomatic VA = 4th or 5th decade
when are the onset of deposits, onset of symptoms, and reduced VA with macular dystrophies?
deposits = 1st decade
symptoms = 1st decade
VA = 1st or 2nd decade
when are the onset of deposits, onset of symptoms, and reduced VA with lattice dystrophies?
deposits = 1st decade
symptoms = 2nd decade
VA = 2nd or 3rd decade
what type of hereditary pattern are granular, macular and lattice dystrophies?
granular = AD
macular = AR
lattice = AD
are erosions common in granular, macular or lattice dystrophies?
granular = uncommon
macular = very common
lattice = very common
what type of opacities are present in granular dystrophy?
discrete sharp boarders, intervening stroma is clear early but becomes hazy, not to limbus
what type of opacities are present in macular dystrophy?
indistinct margins, hazy intervening stroma, extends to limbus, endothelium affected
what type of opacities are present in lattice dystrophy?
early refractive lines and dots, supepithelial spots, diffuse central haze, limbal zone clear in mild cases
what is the corneal thickness in granular, macular and lattice dystrophies?
granular = normal macular = thinned lattice = normal
what is the deposit type in granular, macular and lattice dystrophies?
granular = hyaline macular = glycosaminglycan lattice = amyloid
what are the clinical features in granular, macular and lattice dystrophies?
granular = clear limbal zone macular = opacities reach limbus, cornea thinned lattice = lattice lines
what type of dystrophy is this?
EBMD - dots/maps/microcysts
what type of dystrophy is this?
Schnyder’s central crystalline dystrophy
what is wrong with this cornea?
stromal edema
what type of EBMD is seen here?
fingerprints
what type of EBMD is seen here?
negative staining map
what dystrophy is in this photo?
filamentous lattice lesions
what is seen in this photo and which dystrophy gets it?
Guttata - Fuch’s
what type of dystrophy is seen here?
Meesman’s dystrophy
what type of dystrophy is seen in this photo?
Meesman’s
what type of dystrophy is seen here?
posterior polymorpheous (PPD)
what is seen in this photo?
recurrent epithelial errosion
what type of dystrophy is seen here?
Reis-Bucklers dystrophy
what dystrophy is seen here?
macular dystrophy
what type of dystrophy is this?
granular dystrophy
what type of dystrophy is this?
lattice type 1
