Tuesday, June 24, 2008

Corneal dystrophies


EPITHELIUM

Meesmann's corneal dystrophy

  • autosomal dominant
  • presents in 1st decade and progresses into adulthood
  • diffusely distributed intraepithelial cysts that are usually concentrated in the interpalpebral zone
  • in severe cases cysts can rupture on surface causing irritation and photophobia (use bandage CL)
EBMD (Map-Dot fingerprint dystrophy or Cogan's microcystic epithelial dystrophy)
  • autosomal dominant or due to trauma or surgery
  • geographic epithelial changes (maps), opaque irregularities (dots) or concentric irregular lines (fingerprints)
  • results from a thickened basement membrane
  • can result in recurrent corneal erosions (bandage CL)
  • Muro 128 during the day or ung at night may be necessary for up to 3 months (if this fails to prevent recurrent erosions, may need anterior stromal puncture or PTK

BOWMAN'S LAYER

Reis-Buckler's corneal dystrophy

  • autosomal dominant, presents 1st decade of life
  • subepithelial reticular changes that progress until middle age
  • may opacify or induce irregular astigmatism
  • may have erosions (bandage CL)
STROMA

Granular dystrophy
  • autosomal dominant, presents 1-2nd decade of life
  • grayish white opacities form in the central (almost never periphery) anterior stroma with clear intervening space
  • lesions can become larger and more numerous with stromal hazing
Macular dystrophy

  • rarest (autosomal recessive)
  • anterior stroma becomes hazy in 1st decade, progressing to opacified lesions
  • more likely to affect peripheral cornea
  • worse visual prognosis
Lattice dystrophy

  • autosomal dominant, 1st decade
  • refractile lines in the anterior stroma which eventually branch and develop deeper into stroma (lattice design)
  • prone to erosions (bandage CL)
ENDOTHELIUM

Posterior polymorphous dystrophy (PPD)

  • vesicles deep into the cornea that may be isolated, mutiple/coalesced, or broad bands/train tracks
  • may apear blister-like and have a gray white halo aroudn them
  • increased risk of glaucoma
Fuch's endothelial dystrophy

  • guttata (refractice excrescenses) on posterior cornea due to abnormal functioning endothelial cells (from aging, trauma or inflammation)
  • Fuch's is diagnosed when nonfunctioning endo causes corneal edema
  • vision worse upon awakening
  • muro 128 gtts and ung
  • extreme epithelial edema may cause bulae with pain and photophobia (bandage CL)
  • usually have cataracts
  • cataract surgery may cause a dramatic worsening of Fuch's

BANDAGE CL

  • use steeper curve (unless there is no mvmt then use flatter one)

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