An advanced case is usually readily apparent to the examiner, and can provide for an unambiguous diagnosis prior to more specialized testing. Under close examination, a ring of yellow-brown to olive-green pigmentation known as a Fleischer ring can be observed in around half of keratoconic eyes. The Fleischer ring, caused by deposition of the iron oxide hemosiderin within the corneal epithelium, is subtle and may not be readily detectable in all cases, but becomes more evident when viewed under a cobalt blue filter. Similarly, around 50% of subjects exhibit Vogts striae, fine stress lines within the cornea caused by stretching and thinning. The striae temporarily disappear while slight pressure is applied to the eyeball. A highly pronounced cone can create a V-shaped indentation in the lower eyelid when the persons gaze is directed downwards, known as Munsons sign. Other clinical signs of keratoconus will normally have presented themselves long before Munsons sign becomes apparent, and so this finding, though a classic sign of the disease, tends not to be of primary diagnostic importance. A handheld keratoscope, sometimes known as "Placidos disk", can provide a simple noninvasive visualization of the surface of the cornea by projecting a series of concentric rings of light onto the cornea. A more definitive diagnosis can be obtained using corneal topography, in which an automated instrument projects the illuminated pattern onto the cornea and determines its topography from analysis of the digital image.
Prognosis
Studies of the life expectancy of patients with Alport syndrome are rare, but one 2012 study found that Alport patients receiving renal replacement therapy (dialysis or kidney transplantation) exhibited, on average, better survival compared with matched controls who had other renal diseases (and who also received renal replacement therapy). See also
AMMECR1
Samoyed hereditary glomerulopathy, a disease shown to be a model for Alport syndrome. Fechtner syndrome
Thin basement membrane disease

References
This article incorporates public domain material from the United States National Library of Medicine document: "Alport syndrome". (Genetics Home Reference)

External links

GeneReview/NIH/UW entry on Alport syndrome