Flat Preparation and Scanning Electron Microscopic Findings of Corneal Guttata

PURPOSE: The corneas obtained from 38 donor eyeballs were examined whether corneal guttata was present or not by flat preparation(15 eyeballs) and scanning electron microscopy(23 eyeballs) in order to investigate the relationship between age and the incidence of corneal guttata. METHODS: The corneal endothelial cells with Descemet's membrane were prepared on slides flat and examined by light microscope. The surface of the corneal endothelial cells was examined by scanning electron microscopy. RESULTS: The endothelial excrescences with pigment deposit were shown at the corneal periphery near the trabecular meshwork. The oval to round shaped corneal warts were isolated or confluent in shape. The corneal endothelial cells were variable in size. The cytoplasmic processes were observed on the surface of the bare Descemet's membrane. The fibrillar structure of the degenerating cytoplasm of the corneal endothelial cells over the corneal warts was shown with central pit. The fibrillar excrescences over Descemet's membrane was in banded structures. CONCLUSIONS: In normal cornea, corneal guttata was observed by flat preparation in all cases over 43 years. The endothelial edema was noted in two eyes combined with corneal guttata with the degeneration or loss of corneal endothelial cell.

Histochemical Electron Microscopic Findings of Traumatic Cataract in Rabbits by Ruthenium Red

Glycosaminoglycans (GAGs)are essential components of the extracellular matrix of various tissues.They have been known to regulate cellular and extracellular environments for cell survival and differentiation in various physiologic and pathologic conditions.The present study was conducted to identify the distribution of GAGs in subepithelial cortical fibers of normal and traumatic cataractous lens of rabbits. Traumatic cataract was made by piercing the anterior lens capsule with 25-gauge sharp needle and the rabbits were killed at different time intervals (1, 2, 3 and 4 weeks).From the enucleated eyes subepithelial lens cortical fibers were obtained.A normal rabbit lens was used for the control. The specimens were stained with 0.05%ruthenium red (RR)and processed for histochemical electron microscopy. RR reactive materials were identified as fine granular or filamentous structures.In normal rabbit lens they were present mainly along the surface of lens epithelial cells, the surface of the subepithelial cortical fibers. In cataractous rabbits lens, strong RR positive reactions were observed along the surface of the lens epithelial cells and subepthelial cortical fibers as well as at the intercortical fiber spaces and even within its micro-organelles. This investigation resulted in an illustration of the ultrastructural distribution of GAGs in normal and traumatic cataractous lens of rabbit.this may suggest altered GAG distribution may closely related to the formation of lens opacity.