![]() ![]() Sp1, a transcription facter known to suppress a1-PI promoter activity, has been found to be elevated in these same patients. Various publications have demonstrated decreased levels of alpha1-proteinase inhibitor (a1-PI) within the stroma of keratoconus patients. In an attempt to uncover the mechanism behind the noninflammatory corneal ectasias, specific gene products have been investigated. Additional findings include central epithelial hyperplasia, neovascularization and scarring of the stroma, disruptions in Descemet's membrane, as well as thickening of Descemet's membrane. Despite this thinning, stromal lamellar organization remains unchanged from its normal configuration. Keratoglobus characteristically exhibits diffuse stromal thinning as well as focal disruptions in Bowman's layer which are most severe in the peripheral cornea. Unlike other noninflammatory corneal ectasias such as keratoconus, eye rubbing has not been designated a risk factor. However, associations between keratoglobus and disorders such as Ehlers-Danlos type VI, Marfan syndrome, and the blue sclera syndrome indicate that the etiology may result from defects in collagen synthesis. It is associated with vernal keratoconjunctivitis, dysthyroid ophthalmopathy, and chronic marginal blepharitis. The acquired form presents in adulthood and may evolve from preexisting cases of pellucid marginal degeneration or keratoconus. The congenital form is present at birth and is associated with Ehler-Danlos type VI, Leber congenital amaurosis, and the blue sclera syndrome.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |