EXPERIMENTAL TRAUMATIC CATARACT .2. TRANSMISSION ELECTRON-MICROSCOPY AND EXTRACELLULAR TRACER STUDY

Abstract

Lens changes from injury to the anterior part of the lens were studied with Procion yellow as an extracellular tracer and by transmission electron microscopy at different time intervals after trauma in rats and rabbits. Findings were related to the slit-lamp appearance of the wounded lenses. In the rat lens, a posterior subcapsular cataract developed within the 1st h after trauma. Within 1 h after injury, the fluorescent tracer appeared at the wound and the posterior pole. Swelling of lens fiber cells and the formation of large syncytical aggregates were found as the posterior opacity enlarged. These changes reached the anterior subcapsular cortex via the equatorial cortex after about 1 mo. In the rabbit lens, a slight cellular swelling occurred in the subcapsular cortex. Only 1 of 15 lenses developed a posterior subcapsular opacity after about 1 wk despite a large wound. The uptake of Procion yellow was most prominent in the wound area and never observed at the posterior pole. No further penetration of the dye occurred through the wound after the epithelium sealed the wound by regeneration. The importance of epithelial wound sealing, the restored cellular barrier at the posterior pole and the significance of these factors in cataract progression are discussed.