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Contact Lens 3 > Corneal Dystrophies Kwan > Flashcards

Corneal Dystrophies Kwan Flashcards

1
Q

key characteristics of corneal DEGENERATIONS

A
  • peripheral cornea affected more often
  • local and systemic diseases associated
  • occurs sporadically, can occur in presence of inflammation and neo
  • can be unilateral but often bilateral
  • progression varies, but can be rapid
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2
Q

list of some age-related corneal degenerations

A
  • arcus
  • Vogt’s limbal girdle
  • crocodile shagreen
  • hassall-henle bodies
  • corneal farinata
  • polymorphic amyloid degeneration
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3
Q

list of some NON age-related corneal degenerations

A
  • band keratopathy
  • terrien marginal degeneration
  • spheroidal degeneration
  • salzmann nodular degeneration
  • pellucid marginal degeneration
  • pigmentary iron lines
  • coats white ring
  • lipid keratopathy
  • corneal deposits
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4
Q

what is an Arcus caused by

A

depositions of lipid in the peripheral corneal stroma

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5
Q

where are lipid deposits first seen in Arcus? (what layers)

A

near Descemet’s membrane and later near Bowman’s

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6
Q

what sectoral pattern does the Arcus usually follow? (which area affected first)

A

-inferior
-superior
-nasal
-temporal
(complete ring)

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7
Q

where is the clear zone in an Arcus?

A

between limbus and lipid deposition

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8
Q

what is “furrow degeneration” in Arcus?

A

thinning that occurs in clear zone

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9
Q

what are some trends for ages/races/sex affected by Arcus

A
  • 100% of men over 80
  • women later
  • african americans earlier
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10
Q

what if you have a a patient under 40 with arcus

A
  • indication for laboratory testing

- suspect hypercholestereia, lipid abnormalities

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11
Q

what if you have a patient with unilateral arcus?

A

-eye without arcus is the side where carotid artery disease may be more severe

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12
Q

condition that is a bilateral yellow-white band at the nasal and temporal limbus of the peripheral cornea and incidence increases with age

A

Vogt’s limbal girdle

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13
Q

which type of Vogt’s Limbal Girdle:

  • well demarcated white band that may have holes
  • clear area adjacent to limbus
  • early calcific band keratopathy
A

Type 1

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14
Q

which type of Vogt’s Limbal Girdle:

  • solid chalky white band without holes or clear zone
  • may extend centrally in an irregular linear fashion
A

Type 2

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15
Q

describe the appearance of the age related Crocodile Shagreen

A
  • cobblestone or crocodile-skin appearance in the anterior or posterior cornea
  • polygonal gray to white opacities form and are separated by lucent lines
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16
Q

condition containing sub epithelial calcium deposits in Bowman’s layer that is associated with chronic ocular inflammatory disease (such as uveitis, interstitial keratitis, hypercalcemic states, secondary to topical medication use)

A

Band Keratopathy

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17
Q

what is the appearance and pattern of band keratopathy

A
  • starts as gray-white nasal temporal interpalpebral opacity that advances centrally
  • looks like swiss cheese holes in the band
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18
Q

condition that is a slowly progressive peripheral corneal inflammatory and degenerative disorder with overlying superficial vascularization and characterized by ATR astigmatism

A

Terrien Marginal Degeneration

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19
Q

what is the patient demographic that gets Terrien Marginal Degeneration (age, sex)

A
  • men more affected than women 3:1

- most offen occurs age 20-40

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20
Q

where does Terrien Marginal Degeneration start and what is its appearance

A

generally starts in the supra nasal peripheral cornea with small white opacities in anterior stroma

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21
Q

rare condition that can occur on the cornea, conj, or both and is from UV exposure, aging, environmental, trauma

A

spheroidal degeneration

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22
Q

how does spheroidal degeneration begin and what does it look like as it progresses

A
  • begins with interpalpebral small clear droplets under the epithelium at 3/9 o’clock
  • spherules enlarge, become gold or brown, progress centrally
  • can coalesce into larger droplets and become elevated
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23
Q

what degeneration is characterized by single or multiple white, gray-white, or bluish elevated lesions in the central or peripheral cornea adjacent to an area of corneal scarring, vascularization, edema, or even normal cornea

A

Salzmann Nodular Degeneration

24
Q

what patients get Salzmann Nodular Degeneration

A
  • occurs in eyes that have or have had chronic inflammation

- increases with age and higher in women

25
Q

signs and symptoms of Salzmann Nodular Degeneration

A
  • foreign body sensation

- erosions of the epithelium can occur with notably elevated nodules

26
Q

corneal thinning and ectatic condition characterized by a crescent shaped band of thinning inferior cornea from 4 to 8 o’clock and high ATR astigmatism

A

Pellucid Marginal Degeneration

27
Q

describe the thinning that occurs in Pellucid Marginal Degeneration

A
  • crescent shaped band of thinning inferior cornea from 4 to 8 o’clock
  • thinned area 1-2mm wide and clear
  • corneal stromal thinning and absence of Bowman’s layer in affected area
28
Q

what is the most common epithelial iron line and where is it located?

A

Hudson-Stalhi line in the lower one third of the cornea above eyelid margin

29
Q

what are some key features of corneal DYSTROPHIES

A
  • primary disorders (no systemic involvement)
  • bilateral and symmetrical
  • early onset, usually by 20s
  • involvement of only one layer of the cornea
  • central corneal location
  • autosomal dominant inheritance (AD)
30
Q

what are some epithelial, basement membrane, and Bowman’s layer dystrophies

A
  • epithelial basement membrane dystrophy (EBMD)
  • meesmann epithelial dystrophy
  • reis-bucklers dystrophy
  • stocker-holt, lisch, grayson-willbrandt
  • genetic disease
31
Q

other names for epithelial basement membrane dystrophy (EBMD)

A
  • map-dot fingerprint
  • cogan’s microcystic
  • anterior basement membrane
32
Q

signs and symptoms of epithelial basement membrane dystrophy (EBMD)

A
  • bilateral
  • age of onset usually 20-40
  • about 10% develop painful recurrent epithelial erosions (RCE)
  • otherwise asymptomatic or slight blur
33
Q

why does epithelial basement membrane dystrophy (EBMD) occur?

A
  • abnormal turnover, maturation, and synthesis of the corneal basement membrane
  • blocks normal migration of epithelial cells towards the surface
34
Q

in epithelial basement membrane dystrophy (EBMD), what are the maps and fingerprint lines due to

A

thickening of the basement membrane

35
Q

epithelial basement membrane dystrophy (EBMD), what produces the dot appearance

A

microcysts (trapped cellular debris)

36
Q

what corneal dystrophy is characterized by a myriad of fine, round, intraepithelial cysts of uniform size and shape, interpalpebral zone

A

Meesmann’s Dystrophy

37
Q

what is the age of onset and pattern of progression for Meesmann’s Dystrophy

A
  • visible by 12 months of age, increase in number throughout life
  • asymptomatic until adolescence
  • bilateral, symmetric
  • minority may experience rupture of corneal micro cysts
38
Q

what is the dystrophy of Bowman’s layer causing thickened epithelium, irregular astigmatic, RCE that occurs in early childhood

A

Reis-Bucklers Dystrophy

39
Q

what are some signs and symptoms of Reis-Bucklers Dystrophy

A
  • bilateral, symmetrical
  • RCE, photophobia, foreign body sensation, irritation, pain
  • anterior stromal haze compromises vision in 2nd and 3rd decades
  • honeycomb or fishnet shaped opacities within the central cornea, Bowman’s and anterior stroma
40
Q

what is the most common stromal dystrophy

A

granular dystrophy

41
Q

stromal dystrophy from deposition of branching figures containing amyloid and develops in teenage years

A

lattice dystrophy

42
Q

signs and symptoms of lattice dystrophy

A
  • thin, centrally located branches associated with sub epithelial opacities and anterior stream haze
  • can have painful bilateral RCE
  • often requires penetrating keratoplasty in third or fourth decade of life (5% recurrence rate in corneal graft)
43
Q

stromal dystrophy characterized by grayish white round opacities in the anterior central stroma from hyaline deposition that onsets in the 1st decade

A

granular dystrophy

44
Q

signs and symptoms of granular dystrophy

A

-breadcrumb, snowflake, popcorn looking opacities
-onset in 1st decade but few visual disturbances until 5th decade (after opacities increased in number and size and coalesced)
-photophobia from deposits scattering light
(but RCE episodes are rare)

45
Q

what stromal dystrophy is autosomal recessive, onsets in first decade, is characterized by progressive visual impairment, and is from MPS accumulation?

A

macular dystrophy

46
Q

signs and symptoms of macular dystrophy

A
  • RCE, attacks of severe irritation and photophobia
  • diffuse superficial clouding in central cornea (can extend peripheral)
  • gray-white opacities with indistinct borders, ground glass haze
  • descemet’s membrane and endothelium affected (but epithelium spared)
47
Q

minimum amount of endothelial cells you need

A

1000-1200 cell/mm^2 (density)

48
Q

what % of endothelial cell loss can you get with intraocular surgery

A

0-30%

49
Q

what is normal attrition of endothelial cells/year

A

central cornea loses 100 to 500 cells per year

50
Q

signs and symptoms of Fuchs

A
  • progressive, guttatae, thickening of Descemet’s membrane
  • loss of endothelial cell density, stream edema
  • blur predominately in the morning
  • age of onset 40-60
  • women affected more 3:1
  • epithelial bull, bullous keratopathy
51
Q

what genetic testing is a 96% positive predictive value for Fuchs

A

repeating trinucleotide (TGC in the TCF4 gene)

52
Q

what are some key features of the rare congenital hereditary endothelial dystrophy (CHED)

A

bilateral diffuse corneal clouding, hazy to milky

  • progression over 1-10 years
  • no recurrence in grafted cornea
53
Q

which type of congenital hereditary endothelial dystrophy (CHED) has:

  • onset delayed until first year(s) of life
  • photophobia, tearing
  • hearing deficient, slowly progressive
A 
CHED 1
(autosomal dominant, more common)
54
Q

which type of congenital hereditary endothelial dystrophy (CHED) has:

  • diagnosed at or shortly after birth (within 1 year)
  • nystagmus, ambylopia
  • severe edema - corneal thickness 2-3x the normal values
A 
CHED 2
(autosomal recessive, more severe)
55
Q

what dystrophy is characterized by edematous clouding and secondary sub epithelial band-shaped keratopathy that is slow to non progressive, asymmetric course

A

posterior polymorphous dystrophy (PPMD)

56
Q

signs/ symptoms of posterior polymorphous dystrophy (PPMD)

A
  • isolated, confluent or clustered vesicular and blister like lesions as well as “railroad tracks”
  • secondary glaucoma secondary to trabecular invasion

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