Contact clinical specular microscopy of the corneal endothelium: optical modifications to the applanating objective cone.

The value of clinical specular microscopy of the corneal endothelium has been limited by the extremely small field of view of the image obtained. This is largely a result of an overlying brilliant reflection from the objective (or air)/cornea interface. A modification to the applanating objective cone of the contract specular microscope is described, which virtually eliminates this reflection and gives a visible field of almost 1 mm2 of the endothelium. The theory behind the objective modification is presented, and other advantages of the system, such as reduction of eye movement, are noted.