Abstract
Purpose: :
To investigate the spatial variation of damage to rabbit retina following ischemia-reperfusion injury.
Methods: :
Acute ischemia in the retina was induced in rabbits by increasing intraocular pressure to 140 mmHg for a period of 60 minutes. Thereafter, the eyes were reperfused at normal intraocular pressure for 24 hours. These retinas were examined with light and transmission electron microscopy, and terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining was performed to detect apoptosis. The damage was compared among four parts of the retina (upper unmyelinated region, myelinated region, visual streak, and lower unmyelinated region).
Results: :
In TUNEL assays, the percentage of cells that underwent apoptosis was significantly higher in the visual streak than in the other parts of the retina (P<0.05), while few TUNEL-positive cells were observed in the upper unmyelinated region. Histopathologic findings by electron microscopic examination further revealed cellular edema, vacuolization and chromatin condensation in the visual streak, whereas the ultrastructure of the upper unmyelinated region was least affected by the ischemia-reperfusion injury.
Conclusions: :
Our results suggest that visual streak of the rabbit retina is the most vulnerable part after ischemia-reperfusion injury.
Keywords: retina • ischemia • apoptosis/cell death