Electron microscopy of corneal surface microdiathermy

Abstract
Microdiathermy has recently been shown to be effective in the treatment of persistent corneal epithelial recurrent erosion. In order to determine the mechanism of action of microdiathermy on the anterior surface of the cornea, rabbit eyes were treated with microdiathermy and the course of corneal tissue repair studied by EM. Shortly after treatment, the epithelium is edematous and necrotic and the lamina densa is thickened. Within 24 h, the epithelium appears healed and some hemidesmosomes are present, but the lamina densa is still thickened. At 2 wk the epithelial surface is undulated and protrudes into the stroma in areas where the lamina densa is disrupted. Hemidesmosomes are absent in these regions. Activated fibroblasts are present in superficial stroma. At 4 wk following microdiathermy, there is segmental deposition of new lamina densa and a connective tissue zone between the newly deposited lamina densa and the old lamina densa. Hemidesmosomes are present only in areas of newly deposited lamina densa. Between 6 wk and 3 mo. the epithelial basal surface becomes more uniform with mature hemidesmosomes and the new lamina densa is complete. The old lamina densa remains below it but is no longer present by 6 mo. The mechanism of action for microdiathermy in recurrent erosion is believed to be as follows: in the treated area, epithelium and activated fibroblasts secrete a new connective tissue layer, which provides a suitable substrate to which the epithelium can adhere until it secretes a new lamina densa and hemidesmosome formation can occur.

This publication has 31 references indexed in Scilit: