Glycosylation & Disease

, Volume 1, Issue 3, pp 143–151 | Cite as

An erroneous glycosaminoglycan metabolism leads to corneal opacification in macular corneal dystrophy

  • Andrew J. Quantock


Macular corneal dystrophy (MCD) is a rare, potentially blinding disease whose fundamental genetic defect and exact pathogenesis are yet to be elucidated. It is, however, an especially interesting pathology, which highlights how an erroneous glycosaminoglycan or proteoglycan metabolism can induce physical symptoms in a specific connective tissue. Based on immunochemical data, MCD is a heterogeneous condition, and at least two types of the disease have been identified. The cornea, cartilage, and serum from MCD type I patients all contain an unsulphated form of keratan sulphate. In contrast, these tissues contain normally sulphated keratan sulphate in MCD type II patients. A normal population of keratan sulphate proteoglycans (and chondroitin/dermatan sulphate proteoglycans) in the cornea seems to be a requirement of corneal transparency. However, a clinical diagnosis of MCD is unable to distinguish between the keratan sulphate positive and negative types of MCD. The histopathology of MCD is fairly well established, and various corneal aberrations—such as fibrillogranular and glycosaminoglycan deposits, abnormal diameter collagen, and collagen-free lacunae—result in a breakdown of the regular corneal architecture that presumably contributes to the subsequent corneal opacification.


cornea glycosaminoglycans proteoglycans 


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© Rapid Communications of Oxford Ltd 1994

Authors and Affiliations

  • Andrew J. Quantock
    • 1
  1. 1.Anheuser-Busch Eye Institute, Department of OphthalmologySaint Louis UniversitySt. LouisUSA

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