Cornea Degeneration (Cale)

Question 1

anatomy and physio of cornea

Answer 1

epithelium: genesis, proliferation/migration, healing, cell junctions
stroma: generation, transparancy, hydrophilic
endothelium: energy, ion pumps

Question 2

Degeneration

Answer 2

a process in which normal elements of corneal tissue are converted (involutional and metabolic disease)
represents a change in tissue (benign and detrimental to normal function)
family history or genetic predispositon

Question 3

corneal degenerations that are benign and non-sight threatening

Answer 3

crocodile shagreen
arcus senilis
limbal girdle of vogt
farinata

Question 4

crocodile shagreen

Answer 4

anterior: at level of bowmans layer
posterior: at the posterior corneal stroma and desemets
asymptomatic, age related

Question 5

arcus

Answer 5

lucid interval- superficial lipid deposition ends at bowman’s

Question 6

limble girdle of vogt

Answer 6

type 1: lucid interval-deposition ends at bowmans. swiss cheese holes. sharp edge centrally. early form of of band keratopathy
type II (true vogt): to limbus- elastoid degeneration of subepithelial collagen. extensions centrally

Question 7

peripheral thinning disease

Answer 7

furrow degeneration, terrien’s marginal degeneration, mooren’s ulcer, peripheral ulcerative keratitis, pellucid marginal degeneration

Question 8

Terrien’s Marginal Degeneration

Answer 8

typically asymptomatic and bilateral. can have pain, episcleritis, scleritis. epithelium is intact. thinning of peripheral corneal stroma, superior nasal then circumferential, marginal opacification with superficial vascularization, 75% males, young adult to elderly

Question 9

DiffDx to Terrien’s marginal degeneration

Answer 9

mooren’s ulcer

Question 10

Mooren’s ulcer

Answer 10

painful, red eye, photophobia, NaFl staining ulcer (epithelium not intact), near limbus (progressive), thinning, stromal melting, potentially perforation

Question 11

Mooren’s types

Answer 11

type 1: typically seen in older pt, unilateral, better response to treatment
type 2: younger (indian or african), 20-30yo, bilateral, poor response to treatment

Question 12

how is terrien’s different from Mooren’s?

Answer 12

epithelium intact, no NaFl, stain, rarely painful, inflammatory, rarely aggressive, rarely move centrally, rarely perforates

Question 13

Systemic work up

Answer 13

mandatory referral to rheumatology for vasculitis or collagen vascular disease. autoimmune dz: ankylosing spondylitis, polyarteritis nodosa, psoriatic arthritis, rheumatoid arthritis, scleroderma, lupus, Sjogren syndrome, scleroderma, temporal arteritis, Wegener’s granulomatosis

Question 14

Mooren’s ulcer treatment

Answer 14

no well established treatment, mostly supportive to control inflammation, topical steroids, conj resection, radiation, bandage CL, topical steroid, cyclosporine or systemic immunosuppresion, perforation: tx with cyanoacrylate or lamellar keratoplasty

Question 15

Peripheral ulcerative keratitis (PUK)

Answer 15

associated with autoimmune disease (rheumatoid arthritis, wegners granulomatosis), limbal crescent ulceration (epithelial defect, thinning, progresses circumferentially with extension in sclera), usually episcleritis or scleritis

Question 16

treatment for peripheral ulcerative keratitis

Answer 16

rheumatology referral: systemic immunosuppression, NO topical steroids

Question 17

miscellaneous degenerations

Answer 17

amyloid degeneration
spheroidal degeneration
salzmann’s nodular degeneration
band keratopathy

Question 18

Salzmann’s Nodular degeneration

Answer 18

> females, >50yo, may be inflammatory, hyaline nodules replace bowmans, elevated, bluish-white

Question 19

what is salzmann’s nodular degeneration associated with

Answer 19

chronic ocular surface disease and/or previous inflammation, especially viral (phlyctenular keratoconj, interstitial keratitis, vernal keratitis, trachoma, rarely no clear history of preceding eye disease)

Question 20

Salzmann’s symptoms

Answer 20

dry eye, VA if central or irregular astigmatism

Question 21

management for Salzmann’s

Answer 21

lubricants, steroid if inflamed, bandage CL, in severe cases the nodules can be removed by corneal specialist, penetrating keratoplasty

Question 22

band keratopathy

Answer 22

interpalpebral Ca deposits in bowmans with clear zone separating the limbus. inflammatory dz, mercury. systemic conditions that cause increase Ca. chronic ocular pathology and degenerative conditions

Question 23

why does band keratopathy have the swiss cheese appearance

Answer 23

clear areas and small circular areas where nerve endings perforate the bowmans layer are seen within the band

Question 24

difference between Vogt’s limbal girdle II and band keratopathy

Answer 24

no lucid interval, no swiss cheese, bilateral, does NOT spread across central cornea

Question 25

what is band keratopathy similar to

Answer 25

Vogt’s I

Question 26

plan, treatment, management for band keratopathy

Answer 26

monitor, ocular lubricants for mild cases, refer for hypercalcemic workup, chelation using 2% EDTA for severe cases, PTK (phototherapeutic keratectomy)

Question 27

phthsis bulbi

Answer 27

degenerative atrophic condition of chronic sick eye that may see band keratopathy involving all layers of cornea

Question 28

corneal ectasias

Answer 28

keratoconus (anterior and posterior), keratoglobus, pellucid marginal degeneration

Question 29

keratoconus

Answer 29

bilateral (forme fruste), after puberty (progressive then stabilizes), greater association with down’s, Ehler’s Danlos, Marfan’s, Oculodigital sign: Leber’s, atopic disease

Question 30

pathology of keratoconus

Answer 30

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

Question 31

keratoconus pathophysiology uncertain

Answer 31

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

Question 32

diagnosis for keratoconus

Answer 32

keratometry >47.20, inferior steepening 1.2D>superior, skewing of axis astigmatism >21 degrees

Question 33

charleaux’s sign

Answer 33

irregular red reflex from retinal retro-illumination (keratoconus)

Question 34

rizzutti’s sign in keratoconus

Answer 34

triangle of light on distal iris

Question 35

keratoconus treatment

Answer 35

appropriate optical correction, specialty RGP, scleral RGP, hybrid CL, penetrating keratoplasty, NOT refractive surgery, intacs, collagen crosslinking

Question 36

posterior keratoconus

Answer 36

posterior diffuse or localized curvature increase, normal anterior surface, sporadic (non-inherited), unilateral, non-progressive, more in females

Question 37

keratoglobus

Answer 37

bilatera, congenital or acquired, diffuse corneal thinning>peripherally (1/3 to 1/5 normal thickness)

Question 38

pellucid marginal degeneration

Answer 38

the thinned area is usually confined to an area of the cornea near inferior limbus most often seen from 4-8. Pot belly cornea, ATR astigmatism and irregular astigmatisim (kissing dove topography pattern)