Crocodile Shagreen

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Original article contributed by: Christopher R. Stelton, MD
All contributors: Christopher R. Stelton, MD and WikiWorks
Review: Not reviewed
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Crocodile Shagreen
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Overview:
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Originally described in 1927 by Weizenblatt and named by Vogt in 1930, crocodile shagreen is thought to be a benign, degenerative condition of the cornea which is usually asymptomatic.


Detailed Description:
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Classically described as a bilateral, symmetric, polygonal opacities within the central posterior corneal stroma. The opacities have indistinct edges with intervening clear spaces. The pattern closely resembles “crocodile skin.”


Epidemiology/Risk Factors:
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It is most commonly associated with advanced age. It may be seen in association with band keratopathy or after traumatic corneal injury. Isolated cases have been reported in pseudoxanthoma elasticum, glaucoma, and polymorphic amyloid degeneration1.


Etiology/Pathophysiology:[edit | edit source]


It is most likely a degenerative disorder with a non-familial pattern of occurrence (in contrast to Central Cloudy Dystrophy of Francois).


Histopathology:[edit | edit source]


Electron microscopy has revealed the presence of vacuoles within the corneal stroma, which contain electron-dense material1. A sawtooth-like configuration of the collagenous lamellae which make up the corneal stroma is present, and this alteration of the collagenous lamellae may lead to the polygonal opacities observed clinically1.


Differential Diagnosis:[edit | edit source]


Central Cloudy Dystrophy of Francois (autosomal dominant transmission)
Fluorescein staining after pressure patching (superficial cornea), ocular hypotony, or flattening of keratoconic cornea by a hard contact lens


Management/Treatment:[edit | edit source]


This condition is not believed to cause reduced vision. No treatment is necessary.


Prognosis:[edit | edit source]


Very good, usually asymptomatic.



References:[edit | edit source]


1. Belliveau, Brownstein, Agapitos, Font. Ultrastructural Features of Posterior Crocodile Shagreen of the Cornea. Survery of Ophthalmology 2009; 54 (5); 569-575.
2. Tripathi RC and Bron AJ. British Journal of Ophthalmology 1975; 59; 59.