Table 2

Summary of the Clinical Features of the Corneal Dystrophies
	Disease onset	Visual acuity	Clinical appearance of cornea on slit-lamp biomicroscropy

SUPERFICIAL CORNEAL DYSTROPHIES
MECD	Early childhood	Vision rarely blurred	Multiple distinct epithelial vesicles
RBCD	Childhood	Progressive visual impairment	Confluent irregular geographic opacities in Bowman layer and superficial stroma
TBCD	First/second decade	Progressive visual impairment	Subepithelial honeycomb opacities in central superficial cornea
GDCD	First/second decade	Marked visual impairment	Subepithelial nodular deposits and late staining of fluorescein
LECD	Childhood	Sometimes impaired	Epithelial opacities in different patterns
ERED	First decade	Sometimes impaired	Epithelial erosions
SMCD	First decade	Progressive loss of vision	Subepithelial opacities
CORNEAL STROMAL DYSTROPHIES
MCD	Usually childhood	Eventually severe visual impairment	Thinner than normal cornea with diffuse corneal haze with irregular shaped whitish opacities
GCD type I	Childhood	Progressive visual impairment	Well-defined granules that sometimes resemble crushed bread crumbs within a crystal clear cornea
GCD type II	First/second decade	Progressive impairment of vision	Variable shaped opacities in a clear superficial mid stroma of the cornea. Lattice lines sometimes appear in deeper cornea
LCD type I and variants	First decade	Progressive visual impairment	Delicate branching interwoven linear opacities occur in association with ovoid dots
LCD type II	Third/fourth decade	Vision usually normal until sixth decade	Corneal opacities forming lattice lines are found mainly in the peripheral cornea
FCD	At birth	Normal	small discrete dandruff or ring shaped, fleck like opacities
SCD	Early in life	Progressive decrease in visual acuity	Central corneal haze or subepithelial crystals
CSCD	Before birth	Moderate to severe visual loss	Diffuse corneal clouding with flake-like opacities throughout stroma
PACD	Infancy or childhood	Mildly affected	Diffuse sheet-like opacities especially in posterior corneal stroma
POSTERIOR DYSTROPHIES
FECD	Variable but usually fourth decade or later	Progressive visual impairment	Diffuse thickening of Descemet membrane with excrescences (guttae). Endothelial cells sparse and atrophic
PPCD	Early childhood	Rarely progressive visual impairment	Variable shaped abnormalities of the corneal endothelium
CHED1	Occasionally at birth, but usually in first/second decade	Blurred vision that worsens in the morning	Thickened cornea with diffuse clouding with occasional focal gray spots
CHED2	At birth	Blurred vision	Thickened cornea with diffuse clouding with occasional focal gray spots
XECD	At birth	Blurred vision common in males	Cloudy cornea (only in males) with moon crater-like endothelial cells

Klintworth Orphanet Journal of Rare Diseases 2009 4:7 doi:10.1186/1750-1172-4-7