Lecture 8: Corneal Dystrophies and Degenerations

define corneal degeneration

corneal tissue deterioration caused by inflammation, age, or systemic dz

- non familial

- later onset

- deposition of material, thinning of tissue, or vascularization

define corneal dystrophy

group of genetic corneal diseases that are:

- bilateral

- symmetric

- early onset

- NOT related to env or systemic factors

Corneal dystrophies

time it takes for turnover of entire cornea?

7 days

describe the layers of the epithelium

surface cells

- 2 cells thick

- tight junctions

middle layer

- 2 to 3 layers of wing cells

- desmosomes tightly connect wing cells to each other

last layer

- 1 layer of columnar basal cells

Basement membrane problems lead to 

erosions

What type of dystrophy is Epithelial Basement Membrane Dystrophy?

epi and subepi dystrophy

what does EBMD look like

bilateral and asymmetric

1. map like patterns

2. whorl or fingerprint-like lines

3. dot-like epi lesions

4. blebs

EBMD is autosomal _

dominant (but most cases have no documented inheritance so it is better classified as age-related degeneration)

histopathology of EBMD

thickened basement membrane extending into the epi

why is there neg staining in EBMD?

bc the basement membrane is too thick and causes elevation

symptoms of EBMD?

similar to RCE: FB sensation, pain upon awakening

onset of EBMD?

2nd decade of life

is tx for EBMD necessary?

only if symptomatic

RCE etiology

poor epi attachment to basement membrane secondary to trauma or EBMD

tx for RCE

lubrication

5% sodium chloride

BCL

tx for RCE in recalcitrant cases

doxycycline

amniotic membrane

SK: mechanical debidment of epi

PTK: SK + laser

Describe appearance of Meesman Corneal Dystrophy

tiny intraepi cycts

"meesly lil dots"

Meesman Corneal Dystrophy

Etiology of Meesman Corneal Dystrophy

irregular thickening of epi basement membrane and keratin containing cysts

What are the 3 epi-stromal TGFB1

Reis-Bucklers

Lattice

Granular Type 1 and 2

Reis-Buckler Sx/Sn

Reis-Buckler Tx

Reis-Buckler is a dystrophy of what layer?

Bowman's

Describe appearance of Reis-Buckler

grey/white, fine, round, subepi opacities geographic like

Symptoms of Reis-Buckler

reduced vision from scarring of Bowman's

Histology of Reis-Buckler

replacement of Bowman's w fibrocellular scar tissue

Tx for Reis-Buckler

treat RCE

PTK or SK

lamellar keratoplasty for severe cases

Onset of Reis-Buckler

1st/2nd decade

Stroma

Granular Corneal Dystrophy Type 1

Describe appearance of Granular Corneal Dystrophy Type 1

white, crumb-like deposites w sharply demarcated borders

Location of Granular Corneal Dystrophy Type 1?

central anterior stroma

Granular Corneal Dystrophy Type 1 is autosomal

dominant

onset of Granular Corneal Dystrophy Type 1

1st decade of life

symps of Granular Corneal Dystrophy Type 1

RCE related

blurry vision

tx for Granular Corneal Dystrophy Type 1

treat RCE

PTK

why is recurrence of Granular Corneal Dystrophy Type 1 common after a corneal transplant?

bc only the central cornea is being transplanted so the peripheral corneal cells can still migrate

Granular Corneal Dystrophy Type 2

Describe appearance of Granular Corneal Dystrophy Type 2

bread-crumb

is a cross b/w granular type 1 and lattice dystrophy

Is Granular Corneal Dystrophy Type 2 worse or milder than type 1?

milder

Onset of Granular Corneal Dystrophy Type 2

1st or 2nd decade

describe appearance of lattice corneal dystrophy

anterior stromal glass-like filamentous lesions that eventually coalesce into lattice lines

does lattice corneal dystrophy impact vision?

yes, stromal haze impedes vision

histology of lattice corneal dystrophy

branching lines of amyloid

symps of lattice corneal dystrophy

RCE related

reduced VA

what is the most common stromal dystrophy

lattice corneal dystrophy

describe the course of lattice corneal dystrophy

progressive w marked visual decrease by 4th decade

what is lattice type 2 associated w?

systemic amyloidsis- bilateral cranial and peripheral neuropathy , dry skin, bilateral facial palsy, protruding lips

what are the 3 stromal corneal dystrophies

macular dystrophy

fleck dystrophy

central cloudy dystrophy of francois

macular corneal dystrophy

describe appearance of macular corneal dystrophy

central, whiteish opacities

what happens to the cornea in macular corneal dystrophy?

it is thinner than normal

how is macular corneal dystrophy diff from granular corneal dystrophy

the deposits involve the limbus and stroma all the way to Descemet's

onset of macular corneal dystrophy

childhood

macular corneal dystrophy is autosomal _

recessive (it's the only one)

histology of macular corneal dystrophy

deposits composed of GAGs accumulated within stromal keratocytes

symps of macular corneal dystrophy

severe visual impairment occurs by 30yo

photophobia

tx for macular corneal dystrophy

treat RCE

PTK or lamellar keratoplasty

"Marilyn Monroe Always Gets Her Men in LA. County" mnemonic

Macular dystrophy: will see mucopolysaccharide: stains w alcian blue

Granular dystrophy: will see hyaline materials: stains w masson-trichrome

Lattice dystrophy: will see amyloid: stains w congo red

describe appearance of Fleck Corneal Dystrophy

small, translucent, gray-white, dandruff flakes

location of Fleck Corneal Dystrophy

scattered throughout the stroma

histology of Fleck Corneal Dystrophy

accumulation of GAGs and lipids in keratocytes

onset of Fleck Corneal Dystrophy

congenital or 1st year of life

describe appearance of Central Cloudy Dystrophy of Francois

polygonal, cloudy opacities separated by clear lines

leather like appearance in the stromal part of central cornea

Descement’s Membrane

Endothelium

why are collagen fibers in the stroma not continuous with those in Descemet's as they are with Bowman's?

bc it's easy to peel off Descemet's and endothelium away from stroma

how is Descemet's able to curl into the anterior chamber?

bc it is elastic

do cells in the endo divide or replicate?

NO

what do metabolic pumps in the endo do?

move ions across cell membranes

what are the 2 posterior corneal dystrophies?

Fuchs Endothelial Corneal Dystrophy

Posterior Polymorphous Corneal Dystrophy

Fuchs Endothelial Corneal Dystrophy is characterized by...

central corneal guttata

Fuchs Endothelial Corneal Dystrophy is also associated w _ edema that may progress to involve the _

stromal

epithelium

symps of Fuchs Endothelial Corneal Dystrophy

reduced vision, worse in AM

pain from ruptured epi bullae

what are guttata

droplet-like accumulations of non-banded collagen on the posterior surface of Descemet's

grading scale for guttata

Grade 0: negative

Grade 1: 0-12 central guttae

Grade 2: Greater than 12 central nonconfluent guttae

Grade 3: 1-2 mm of confluent central guttae

Grade 4: 2-5 mm of confluent central guttae

Grade 5: Greater than 5 mm of confluent central guttae or G4 with stroma or epithelial edema (G5)

onset of Fuchs Endothelial Corneal Dystrophy

4th decade of life or later

do more males or females get Fuchs Endothelial Corneal Dystrophy

females 3:1

how to prevent Fuchs Endothelial Corneal Dystrophy?

you can't

but stop smoking

can Fuchs Endothelial Corneal Dystrophy progress?

yes

tx for Fuchs Endothelial Corneal Dystrophy

5% NaCl

DSAEK

DMEK- best for Fuch's

DWEK

Rho Kinase Inhibitors

pt comes in w guttata, what do u do nect?

1. grade it: for a few guttae, just move on but for a lot, do the next steps

2. ask about blurry vision worse in AM

3. check for corneal edema on slit lamp

4. get baseline pachy reading

5. refer when pt is bothered by reduced VA or when stromal haze is noted

describe appearance of Posterior Polymorphous Corneal Dystrophy

several clinical presentations

1. geographic gray opacities

2. vesicular lesions

3, parallel gray-white endo bands (snail tracks)

pathogenesis of Posterior Polymorphous Corneal Dystrophy

abnormal endo cells that take on properties of epi cells

descemet's thickening

onset of Posterior Polymorphous Corneal Dystrophy

early childhood

what does a severe variant of Posterior Polymorphous Corneal Dystrophy involve?

angle abnormalities and iridocorneal adhesions (rare tho)

list the corneal dystrophies that involve TGFB1 gene

EBMD

Reis-Buckler

Granular Type 1 and 2

Lattice

list the 3 corneal stromal deposits

Ocular Chrysiasis: Gold

Ocular Argryosis: Silver

Wilson's Disease: Kayser-Fleischer ring Copper

describe appearance of Ocular Chrysiasis: Gold

deposition of gold in ocular tissues

dust-like granules scattered in stroma and epi

etiology of Ocular Chrysiasis: Gold

from gold salt tx used for rheumatoid arthritis

describe appearance of Ocular Argryosis: Silver

gray, diffuse opacities in the deep corneal stroma and descemet's

symp of Ocular Argryosis: Silver

reduced dark adaptation

etiology of Ocular Argryosis: Silver

secondary to chronic exposure to silver

tx for Ocular Argryosis: Silver

d/c silver intake or limit exposure

describe appearance of Wilson's Disease

brownish-yellow copper ring

location of Kayer-Fleischer Ring

peripheral descemet's membrane

what is Kayer-Fleischer Ring associated w

sunflower cataract

Wilson's Dz is autosomal _

recessive

Wilson's Dz is caused by a mutation on what chromosome?

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