Findings in the leprous cornea with the slit-lamp microscope.

Findings in nodular iritis of the leprous eye on examination by the slit-lamp microscope were first reported by Peter in 1924. Since then Pillat, Boshoff (1), Kennedy (5), and others have reported on the changes in the leprous eye observed by the same means. Vale (11) in particular has pointed out the importance of the capillary network in the limbus corneae; and Pillat, and also Elliot (2) have stated that the earliest change in the eye is a sheath-like or bead-like lesion in the corneal nerve. These investigators have reported that the slit-lamp microscope is of great aid in the early diagnosis of leprosy, determination of its duration, and also determination of the effect of treatment or the course of the disease. As long since reported in detail by Mitsuda (9), and more recently by Vale (11), the limbus corneae plays an extremely important role in leprous conditions of the eye. The rich capillary and lYmphatic networks are similar to those of the skin, the flow is slow and venous pressure is low, making ideal conditions for the fixation of leprosy bacilli. Furthermore, the capillary network in the limbus controls the nutrition and protection of the cornea, and it is related to the iris and ciliary body. It is also connected with the episclera and conjunctiva by the vessels in the iris, and these sites are favorite locations for leprous affections of the eye. In the early diagnosis of the leprous eye with the slit-lamp microscope, the condition of the limbus corneae should be considered first, especially the capillary network and the formation of leprous nodules. The normal corneal nerves are to be observed as fine lines that generally gleam like silken threads. A triangular or nodular thickening, like the web on the feet of water birds, formed by the perineural fibrillar substance and branching of the nerve-that is, the floating membrane-can be seen physiologically at the fork (10). Biomicroscopical observation of the leprous eye often reveals a sheathlike thickening along the corneal nerve or a bead-like change, especially at the fork (2, 4). Differentiation of the physiological floating membrane and the bead-like change in leprosy is not difficult. In the former, the thickening has a grayish color and the free edge is semilunar in shape and concave, while in the latter the thickening is seen as a white gleaming, round, bead-like mass. The early leprous changes which next appear,. following those in the corneal nerve and limbus corneae, are pannus corneae and iritis. It has