Eye
Cornea
Corneal dystrophy

Author: Nat Pernick, M.D. (see Authors page)

Revised: 1 May 2018, last major update October 2013

Copyright: (c) 2004-2018, PathologyOutlines.com, Inc.

PubMed Search: Corneal dystrophy [title] pathology review[ptyp]

Cite this page: Pernick, N. Cornea: corneal dystrophy. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/eyecorneadystrophy.html. Accessed July 21st, 2018.
Definition / general
  • Heterogeneous group of inherited, bilateral, symmetric corneal disorders
  • Most common is Fuchs dystrophy
  • Also macular, lattice and granular corneal dystrophy
  • Cause severe visual loss reparable by corneal transplantation
Site of damage and types of corneal dystrophy
  • Epithelium:
    • Meesman dystrophy
    • Microcystic
    • Map dot and fingerprint dystrophy
  • Bowman layer and superficial stroma:
    • Granular corneal dystrophy type III
    • Thiel-Behnke dystrophy
    • Familial subepithelial amyloidosis
  • Stroma:
    • Granular corneal dystrophy types I and II
    • Macular corneal dystrophy
    • Central stromal crystalline dystrophy
  • Endothelium:
    • Fuchs dystrophy (see below)
    • Posterior polymorphous dystrophy
    • Congenital hereditary endothelial dystrophy
Types of corneal dystrophy
  • Central stromal crystalline dystrophy:
    • Also called Schnyder corneal dystrophy
    • Disease maps to 1p34-p32
    • Crystals of cholesterol ester in anterior stroma
  • Congenital hereditary endothelial dystrophy:
    • Autosomal dominant (maps to 20q12-q13.1) or autosomal recessive
    • Edematous epithelium with lack of Bowman layer
    • Thickened stroma and Descemet membrane
    • Diminished number of endothelial cells
  • Familial subepithelial amyloidosis:
    • Also called primary gelatinous droplike dystrophy
    • Bowman layer and superficial stroma dystrophy
    • Autosomal recessive
    • Usually due to mutation in M1S1 gene at 1p
    • Has subepithelial amyloid deposits that contain lactoferrin
  • Fleck dystrophy:
    • Also called speckled, cloudy dystrophy
    • Subepithelial and stromal amyloid deposits
    • Autosomal dominant
    • Maps to 2q35
    • Stains with colloidal iron and Alcian blue
  • Granular corneal dystrophy type I:
    • Stromal dystrophy
    • Autosomal dominant
    • Usually due to R555W mutation in TGFB1 gene at 5q31
    • Discrete deposits of mutated protein appear red with Masson trichrome stain
  • Granular corneal dystrophy type II:
    • Also called Avellino corneal dystrophy
    • Autosomal dominant
    • Due to R124H mutation in TGFB1 gene at 5q31
    • Corneal deposits similar to granular corneal dystrophy type I plus amyloid
  • Granular corneal dystrophy type III:
    • Also called Reis-Bucklers dystrophy
    • Bowman layer and superficial stroma dystrophy
    • Autosomal dominant
    • Due to R124L mutation in TGFB1 gene at 5q31
  • Lattice dystrophy:
    • Irregular linear subepithelial and stromal amyloid deposits
    • Normal Descemet membrane and endothelium
    • Birefringent amyloid with Congo Red stain
      • Lattice type I:
        • Autosomal dominant
        • Usually due to R124C mutation in TGFB1 at 5q31
        • Lesions limited to cornea
        • Often recurrent epithelial erosions and subepithelial amyloid or collagenous plaques
      • Lattice type II:
        • Autosomal dominant
        • Mutation in GSN gene at 9q34
        • Associated with familial amyloid polyneuropathy
        • Amyloid is derived from fragment of mutated gelsolin
      • Lattice type III:
        • Autosomal recessive
        • Amyloid deposits thicker than in types I and II
        • Identity of amyloid unknown
      • Lattice type IIIA:
        • Autosomal dominant
        • Amyloid deposits resemble type III
        • Mutation in TGFB1 gene at 5q31
  • Macular corneal dystrophy:
    • Autosomal recessive
    • Due to mutation in CHST6 gene at 16q22.1
    • Deficiency in carbohydrate sulfotransferase
    • Causes deposits of low sulfated keratan sulfate related glycosaminoglycan throughout stroma
    • Descemet membrane and endothelium
    • Also corneal guttae
    • Deposits are positive for colloidal iron and Alcian blue
      • Macular type I:
        • No / low serum keratan sulfate
        • Keratocytes don't react to keratan sulfate antibodies
      • Macular type IA:
        • No / low serum keratan sulfate
        • Keratocytes DO react to keratan sulfate antibodies
      • Macular type II:
        • Normal serum keratan sulfate
        • Keratocytes DO react to keratan sulfate antibodies
  • Meesmann dystrophy:
    • Epithelium dystrophy
    • Autosomal dominant
    • Mutation in keratin KRT3 (12q) or KRT12 gene (17q)
    • Intraepithelial microcysts
  • Microcystic, map dot and fingerprint dystrophy:
    • Epithelium dystrophy with nonspecific features
    • Intraepithelial basement membrane and microcysts
  • Posterior polymorphous dystrophy:
    • Endothelial dystrophy
    • Autosomal dominant (may be due to mutation in COL8A2 at 1p34.3-p32.3), or autosomal recessive
    • May also map to 20q12-q13
    • Abnormal Descemet membrane
    • Has multilayered epithelial cells in posterior cornea
  • Thiel-Behnke dystrophy:
    • Transmission EM shows subepithelial "curly" fibers
    • Due to R555Q mutation in TGFB1 gene at 5q31 or 10q23-q24
    • Focal loss of epithelial basement membrane and Bowman layer
Microscopic (histologic) images

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Lattice dystrophy