The use of specular microscopy to investigate unusual findings in the corneal endothelium and its adjacent structures.

The use of specular microscopy is not confined to the corneal endothelial mosaic, but may be used at any level through the corneal stroma to the posterior endothelial surface. In the stroma the not very dense, irregularly rounded deposits of corneal dystrophies may be differentiated from the dense, geometric shapes of crystalline deposits. At the level of Descemet's membrane the fine parallel lines of tears in Descemet's are distinct from the multiple fine vertical deep stromal lines seen in advanced keratoconus. At the level of the endothelial mosaic the cells may be counted and their morphology examined, while blebs may also be seen in a wide variety of pathological conditions including superficial keratopathies, contact lens wearers, deep keratopathies, anterior uveitis and contusion injury. These blebs vary in size in different conditions and are often transient. They must be distinguished from guttae which are permanent and although an occasional finding in normal corneas are a constant feature of cornea gutatta and Fuchs' dystrophy. On the posterior endothelial surface the relief mode enables the examination of numerous deposits including red blood cells, white blood cells, keratitic precipitates, pigment granules and pseudoexfoliative KP. The morphology of these various findings is discussed.