Macular Corneal Dystrophy
Autosomal Recessive, CHST6 gene, Chromosome 16q22 - abnormal keratan sulfate
Three types have been defined on the basis of immunoreactivity to specific markers of antigenic keratan sulfates
Type 1 : No AgKS reactivity in the cornea or serum
Type 1A : Keratocytes manifest the AgKS reactivity. Not the serum or corneal extracellular material
Type 2 : The abnormal deposits in the cornea and serum have positive AgKS reactivity.
Decreased vision & Photophobia
Anterior stromal white opacities seen in first decade
Opacities progress to form a grainy, ground-glass haze between them
Extend from limbus to limbus
Over time, the cornea thins, endothelium can develop guttae
Recurrent corneal erosions
Decreased corneal sensations
Glycosaminoglycan accumulation within and outside stromal keratocytes beneath the epithelium and within endothelial cells.
Stains with Alcian Blue, Colloidal Iron or PAS stain
Phototherapeutic keratectomy (high risk of recurrence)
Mnemonic for main corneal dystrophies abnormal deposits and staining
"Marylin Monroe Always Gets Her Men in L. A. County"
Macular dystrophy - Mucopolysaccharide - Alcian blue
Granular dystrophy - Hyaline materials - Masson trichrome
Lattice dystrophy - Amyloid - Congo red
Image from Rajan Eye Care Hospital