Loss of corneal sensation may be more profound in advanced cases. Patients who are younger than 23 years demonstrate only a central corneal opacity, which may involve the entire stroma with or without central subepithelial cholesterol crystals. They possess excellent visual acuity and normal corneal sensation. Patients aged 23-39 years develop arcus lipoides. Snellen acuity may be diminished if measured under daylight conditions.
Corneal sensation begins to decrease.
In patients older than 39 years, a midperipheral, panstromal corneal haze appears that fills in the area between the central opacity and the peripheral arcus. Often, the arcus is dense enough to be seen without a slit lamp. In some members of families with this dystrophy, the presence of xanthelasma associated with elevated levels of serum cholesterol, triglycerides, and lipoproteins has been described. Confocal microscopy in more advanced stages of SCCD may reveal the absence of corneal nerves. Electron microscopy reveals dissolved lipid particles scattered in the subepithelial space throughout the stroma and, rarely, the endothelium.