Cornea Degeneration (Cale) Flashcards
anatomy and physio of cornea
epithelium: genesis, proliferation/migration, healing, cell junctions
stroma: generation, transparancy, hydrophilic
endothelium: energy, ion pumps
Degeneration
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
corneal degenerations that are benign and non-sight threatening
crocodile shagreen
arcus senilis
limbal girdle of vogt
farinata
crocodile shagreen
anterior: at level of bowmans layer
posterior: at the posterior corneal stroma and desemets
asymptomatic, age related
arcus
lucid interval- superficial lipid deposition ends at bowman’s
limble girdle of vogt
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
peripheral thinning disease
furrow degeneration, terrien’s marginal degeneration, mooren’s ulcer, peripheral ulcerative keratitis, pellucid marginal degeneration
Terrien’s Marginal Degeneration
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
DiffDx to Terrien’s marginal degeneration
mooren’s ulcer
Mooren’s ulcer
painful, red eye, photophobia, NaFl staining ulcer (epithelium not intact), near limbus (progressive), thinning, stromal melting, potentially perforation
Mooren’s types
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
how is terrien’s different from Mooren’s?
epithelium intact, no NaFl, stain, rarely painful, inflammatory, rarely aggressive, rarely move centrally, rarely perforates
Systemic work up
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
Mooren’s ulcer treatment
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
Peripheral ulcerative keratitis (PUK)
associated with autoimmune disease (rheumatoid arthritis, wegners granulomatosis), limbal crescent ulceration (epithelial defect, thinning, progresses circumferentially with extension in sclera), usually episcleritis or scleritis
treatment for peripheral ulcerative keratitis
rheumatology referral: systemic immunosuppression, NO topical steroids
miscellaneous degenerations
amyloid degeneration
spheroidal degeneration
salzmann’s nodular degeneration
band keratopathy
Salzmann’s Nodular degeneration
> females, >50yo, may be inflammatory, hyaline nodules replace bowmans, elevated, bluish-white
what is salzmann’s nodular degeneration associated with
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)
Salzmann’s symptoms
dry eye, VA if central or irregular astigmatism
management for Salzmann’s
lubricants, steroid if inflamed, bandage CL, in severe cases the nodules can be removed by corneal specialist, penetrating keratoplasty
band keratopathy
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
why does band keratopathy have the swiss cheese appearance
clear areas and small circular areas where nerve endings perforate the bowmans layer are seen within the band
difference between Vogt’s limbal girdle II and band keratopathy
no lucid interval, no swiss cheese, bilateral, does NOT spread across central cornea
what is band keratopathy similar to
Vogt’s I
plan, treatment, management for band keratopathy
monitor, ocular lubricants for mild cases, refer for hypercalcemic workup, chelation using 2% EDTA for severe cases, PTK (phototherapeutic keratectomy)
phthsis bulbi
degenerative atrophic condition of chronic sick eye that may see band keratopathy involving all layers of cornea
corneal ectasias
keratoconus (anterior and posterior), keratoglobus, pellucid marginal degeneration
keratoconus
bilateral (forme fruste), after puberty (progressive then stabilizes), greater association with down’s, Ehler’s Danlos, Marfan’s, Oculodigital sign: Leber’s, atopic disease
pathology of keratoconus
irregular epithelium, breaks in bowman’s, fibrosis beneath epithelium, stromal scarring, corneal thinning
keratoconus pathophysiology uncertain
epithelial lysosomal enzyme expression increase, reduced inhibition of proteolytic enzymes, abnormal corneal collagen, lamellae, keratocyte populations
diagnosis for keratoconus
keratometry >47.20, inferior steepening 1.2D>superior, skewing of axis astigmatism >21 degrees
charleaux’s sign
irregular red reflex from retinal retro-illumination (keratoconus)
rizzutti’s sign in keratoconus
triangle of light on distal iris
keratoconus treatment
appropriate optical correction, specialty RGP, scleral RGP, hybrid CL, penetrating keratoplasty, NOT refractive surgery, intacs, collagen crosslinking
posterior keratoconus
posterior diffuse or localized curvature increase, normal anterior surface, sporadic (non-inherited), unilateral, non-progressive, more in females
keratoglobus
bilatera, congenital or acquired, diffuse corneal thinning>peripherally (1/3 to 1/5 normal thickness)
pellucid marginal degeneration
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)
