Differential specular microscopy in keratopathy and anterior uveitis

Use of the relief mode of specular microscopy to differentiate corneal endothelial changes in anterior segment disease from retrocorneal deposits facilitates understanding of the nature of the endothelial changes. The retrocorneal deposits may be pigment granules or inflammatory deposits. The inflammatory deposits may be due to fibrin or WBCs, are more irregular than pigment, and may coalesce to form large, rounded, keratic precipitates. Pigment granules are smaller, denser, usually more regular and, although sometimes confluent, do not form keratic precipitates. Both are distinct from subendothelial blebs, both the smaller blebs up to one cell in diameter and larger blebs of two to three cells in diameter. These blebs are probably due to edema, disappear quickly on resolution of the pathologic process, and are evidence of stress to the endothelium, which shows significant change in morphology and fall in cell numbers when the blebs are of long-standing.