Cornea Degeneration and Ectasia

Question 1

which layer of the cornea is capable of regeneration? which ones are not?

Answer 1

epithelium is the only layer to undergo mitotic division (Bowman’s, stroma, Descemet’s and endothelium do not regenerate)

Question 2

what are the cell junctions present in the corneal epithelium?

Answer 2

desmosomes and gap junctions and connect to Bowman’s layer via hemidesmosomes

Question 3

what type of pumps are in the corneal endothelium and what is the purpose?

Answer 3

Na-K-ATPase pumps to keep the stroma from having too much fluid

Question 4

what is a degneration?

Answer 4

a process in which normal elements of corneal tissue are converted (age-related or metabolic diseases) - can be benign or detrimental to normal function

Question 5

what are 7 corneal degenerations that are non-sight threatening?

Answer 5

crocodile shagreen, arcus, limbal girdle of vogt, farinata, terriens marginal degeneration, moorens ulcer and amyloid

Question 6

what are 2 non-sight threatening corneal degenerations that have the possibility of turning to sight threatening?

Answer 6

mooren’s ulcer and amyloid

Question 7

what are 3 exmples of degenerations that are opacificiations and sight threatening?

Answer 7

salzmanns nodular, spheroidal and band keratopathy

Question 8

what is crocodile shagreen?

Answer 8

age related, benign, common condition, easily seen with slit lamp = plaques of fibrous tissue

Question 9

where is crocodile shagreen located anteriorly and posteriorly?

Answer 9

anterior = bowman’s layer

posterior = posterior corneal stroma and descemet’s

Question 10

what are the symptoms and treatment for crocodile shagreen?

Answer 10

no symptoms and no treatment required

Question 11

what is arcus?

Answer 11

lipid/cholesterol deposits in Bowman’s (not common under age 40)

Question 12

why does arcus have a lucid interval between the limbus?

Answer 12

the lipid deposition ends at bowman’s - it has an abrupt ending

Question 13

what does type 1 limble girdle of vogt look like?

Answer 13

has a lucid interval - deposition ends at bowman’s swiss cheese holes and sharp edges centrally early form of band keratopathy

Question 14

what does type 2 limble girdle of vogt look like?

Answer 14

goes to limbus - elastoid degeneration of sub-epithelial collagen extensions centrally

Question 15

what is farinata?

Answer 15

white dust-like particles, pre-descemet’s and occurs with aging (may resemble pigment dispersion syndrome)

Question 16

what is the leading line of a pterygium called?

Answer 16

stocker line (iron line)

Question 17

what is a hudson-stahli line?

Answer 17

occurs in the interpalpebral zone from tear stagnation (iron deposits in tear film) = typically after chronic inflammatory condition

Question 18

what is Terrien’s marginal degeneration?

Answer 18

thinning of the cornea (starts superiorly then circumferential), asymptomatic, bilateral and epithelium stays intact, fine line of lipid deposit, superficial vascularization, males >> females and 40+

Question 19

what is a differential diagnosis for Terrien’s marginal degeneration?

Answer 19

Mooren’s ulcer

Question 20

what symptoms will patients have with Mooren’s ulcer?

Answer 20

non-infectious (unknown etiology - autoimmune likely), painful, red, photophobia

Question 21

where does Mooren’s ulcer begin?

Answer 21

near limbus, typically progressive (circumferentially and centrally) = thinning, stromal melting, potentially perforation (epithelium is not intact)

Question 22

what is Mooren’s ulcer type 1?

Answer 22

typically seen in older patients, unilateral and better responses to treatment

Question 23

what is Mooren’s ulcer type 2?

Answer 23

seen in younger (african descent) 20-30 y/o, bilateral and poor response to treatment (rare)

Question 24

how do you differentiate between Mooren’s and Terrien’s?

Answer 24

Terriens has intact epithelium, no NaFl staining, rarely painful/inflammatory, and rarely perforates

Question 25

what type of systemic work up is needed to Mooren's ulcer?

Answer 25

vasculitis or collagen vascular disease (autoimmune diseases)

Question 26

what is the treatment for Mooren's ulcer?

Answer 26

mostly supportive = topical steroids, conjunctival resection/radiation, bandage CL, topical cyclosporine or systemic immunosupression (perforation = cyanoacrylateor lamellar keratoplasty)

Question 27

what is polymorphic amloid degeneration?

Answer 27

occurs deep stroma, bilateral and appears similar to lattice degeneration - mostly benign

Question 28

what is spheroidal degeneration?

Answer 28

common from UV exposure (actinic), usually interpalpebral, golden brown deposits

Question 29

what is Salzmann's nodular degeneration?

Answer 29

elevated white masses on cornea - tend to be peripheral (milky/glossy), can have a red/irritated eye

Question 30

what causes salzmann's nodular degeneration and who typically gets it?

Answer 30

females, \> 50 y/o, chronic ocular surface disease/inflammation (especially viral) - hyaline plaques replace bowman's

Question 31

what are the symptoms and treatment for salzmann's nodular degeneration?

Answer 31

symptoms = dry eye symptoms, VA if central treatment = lubricants, steroid, bandage CL (PK if severe)

Question 32

what is band keratopathy?

Answer 32

interpalpebral CA++ deposits in bowman's with clear zone separating the limbus - swiss cheese appearance

Question 33

why does band keratopathy have swiss cheese appearance?

Answer 33

clear areas and small circular areas where nerve endings perforate bowman's (similar to Vogt 1)

Question 34

what causes band keratopathy?

Answer 34

inflammatory disease (mercury), systemic conditions that cause increased Ca, chronic ocular pathology and degenerative conditions or idiopathic

Question 35

what is the treatment/plan for band keratopathy?

Answer 35

monitor, ocular lubricants for mild cases, refer for hypercalcemic work-up, chelation using 2% EDTA for severe cases, PTK

Question 36

what are 3 corneal ectasias?

Answer 36

keratoconus, keratoglobus, pellucid marginal degeneration

Question 37

when does keratoconus typically occur and what causes it?

Answer 37

bilateral, usually after puberty (rarely congenital), progressive then stabilizes, males = females, \>asians, may have an inheritance pattern

Question 38

what is the pathology for keratoconus?

Answer 38

irregular epithelium, breaks in bowman's, fibrosis beneath epithelium, stromal scarring, corneal thinning

Question 39

what is the pathophysiology for keratoconus?

Answer 39

epithelial lysosomal enzyme expression increase, reduction inhibition of proteolytic enzymes, abnormal corneal collagen, lamellae, keratocyte populations

Question 40

what is charleaux's sign?

Answer 40

an irregular red reflex from retinoscopy or retro-illumination in keratoconus

Question 41

what is Rizutti's sign?

Answer 41

a triangle of light seen on the distal iris in keratoconus

Question 42

what is munson's sign?

Answer 42

when a patient with keratoconus looks down it forms a "V" shape

Question 43

what is vogt striae and fleischer ring?

Answer 43

lines seen in cornea with keratoconus (fleischer ring = iron deposits around base of cone)

Question 44

what is the treatment for keratoconus?

Answer 44

optical correction, specialty RGP/hybrid CL, PK, no refractive surgery, intacts, collagen crosslinking

Question 45

what are corneal hydrops?

Answer 45

spontaneous rupture/break in descemet's - can result in flattening of cornea, clears on its own - may scar

Question 46

what is posterior keratoconus?

Answer 46

posterior diffuse or localized curvature (normal anterior surface), unilateral, non-progressive, female \> male

Question 47

what is keratoglobus?

Answer 47

bilateral, congenital or acquired, diffuse corneal thinning \> peripheral (1/3 to 1/5 normal thickness)

Question 48

what does pellucid marginal degeneration look like?

Answer 48

the thinned area is confined to corneal side of inferior limbus (4:00-8:00), pot belly cornea, ATR astigmatism (kissing dove pattern)

Question 49

what are dermoids?

Answer 49

collection of ectodermal tissues: sweat glands, hair follicles, sebaceous glands

Question 50

what is a lipodermoid?

Answer 50

benign fatty tumor beneath conjunctiva laterally

Question 51

what are trisomy 21, 17-18, and 13?

Answer 51

21 = downs syndrome 17-18 = edwards syndrome 13 = bartholin-patau syndrome

Question 52

what happens with a vitamin A deficiency?

Answer 52

bitot spot, impaired goblet cell function, keratinization

Question 53

what disease is caused by sphingolipidoses disorder?

Answer 53

Fabry's disease

Question 54

what is fabry's disease?

Answer 54

x-linked recessive, posterior spoke like deposits in lens along sutures = verticillata

Question 55

what is cystinosis and alkaptonuria caused by?

Answer 55

diseases of protein and amino acid metabolism

Question 56

what does cystinosis look like?

Answer 56

cystine crystal deposits throughout cornea

Question 57

what type of deposits does ciprofloxacin give?

Answer 57

chalky white deposits where epithelium is absent

Question 58

where do mercury deposits occur? what causes them?

Answer 58

(orange-brown) in bowman's typically from preservatives

Question 59

where do silver deposits occur?

Answer 59

argyrosis in descemet's

Question 60

what type of deposits occur from epinephrine drops?

Answer 60

adrenochrome

Question 61

what type of deposits do the drug thorazine cause? and where do they occur?

Answer 61

stellate sub-capsular throughout the stroma

Question 62

what causes wilson's disease?

Answer 62

defect in copper metabolism - Cu+ deposit in descemet's peripherally with no clear interval

Question 63

what is this picture of?

Answer 63

corneal hydrops

Question 64

what is this picture of?

Answer 64

band keratopathy

Question 65

what is this picture of?

Answer 65

crocodile shagreen

Question 66

what is this picture?

Answer 66

furrow degeneration

Question 67

what is this topography of?

Answer 67

keratoconus

Question 68

what is this topography of?

Answer 68

pellucid marginal degeneration

Question 69

what is this picture of?

Answer 69

Salzmann's nodular degeneration

Question 70

what is this picture of?

Answer 70

vogt striae in keratoconus

Question 71

what is this picture of?

Answer 71

limbal girdle of vogt type 1