RESUMO
OBJECTIVE: To assess the influence of radio frequency (RF) burn on the ultrastructure of rabbits cornea, sclera, lens and retina. METHODS: The cornea and sclera of 24 adult New Zealand rabbits were burned by RF (power 15 W) for 10 seconds. The specimens of cornea, sclera, lens and retina were collected and examined under transmission electron microscopy (TEM) at 2 hours, 24 hours, 3 days and 14 days after burning. RESULTS: The TEM showed corneal epithelial cells nuclear chromatin pyknosis, stromal partial colloid fibers rupture, endothelial cells mitochondria turgescence and vacuolization; scleral fibroblastic nuclear chromatin pyknosis, rough endoplasmic reticulum distention, mitochondria turgescence; lens normal; retinal pigment epithelial cells mitochondria turgescence, photoreceptor cells outer segment disarrangement, inner segment mitochondria turgescence, and outer nuclear layer cells' nuclear chromatin pyknosis, 2 hours after burning. Corneal epithelial cells structure was fairly clear, some mitochondria of endothelial cells were turgescent, scleral fibroblastic mitochondria were slightly turgescent, and retinal structure was almost normal, 3 days after burning. There were no significant changes of cornea, sclera and retina in ultrustructure when the burnt groups were compared with the control group, 14 days after burning. CONCLUSION: These findings suggest that RF can cause direct lesion of cornea, sclera and indirect lesion of retina by burning cornea and selera, but the ultrastructural changes will almost recover 14 days after RF burning.