Abstract:AIM: To investigate the effect of retinal organizational structure on short term intense light exposure rabbit eye model and the mechanism of light injury.
METHODS: Totally 25 healthy New Zealand white rabbits were randomly divided into 5 groups. Rabbit eyes were exposed to 30000 lux simulated solar for 15 minutes and 30 minutes. Then the retinal tissue ultrastructure was observed and photoreceptor cells apoptosis at different time after exposure was detected.
RESULTS: Examination results of 15 minutes light exposure group at 2nd day: membrane structure of photoreceptor outer segment was disordered; lamellar structure was discrete; mitochondrial of the inner segment were swollen and some ridges were ruptured; cell plasm of external granular layer was vacuolated-like; apoptosis rate of photoreceptor cells was 3.26%±0.98%. Examination results of 30 minutes light exposure group at 2nd day: membrane structure of outer segment was disordered; lamellar structure was severely dispersed; mitochondrias of the inner segment were swollen and ridges were ruptured; cell plasm of external granular layer was vacuolated-like; apoptosis rate of photoreceptor cells was 3.63%±1.25%. Examination results of 30 minutes light exposure group at 7th day: organizational structure of outer segment membrane was disordered; lamellar structure was disappeared and vacuolated; mitochondrial of the inner segment were swollen and ridges were ruptured; cell plasm of external granular layer was swollen, vacuolated largely, and disordered; partial membranes were damaged; apoptosis rate of photoreceptor cells was 19.63%±1.32%. Examination results of 30 minutes light exposure group at 14th d: organizational structure of outer segment membrane was recovered orderly; lamellar structure was more compact; mitochondrial of the inner segment were swollen and ridges were ruptured; swollen cell plasm of external granular layer was mitigatory and arranged more regularly; apoptosis rate of photoreceptor cells was 18.98%±1.13%.
CONCLUSION: Results demonstrate that 30000lux stimulated solar radiation for 15 minutes led to acute photodamage of rabbit retina, showing retinal photoreceptor cells degeneration which is the important mechanism of photoreceptor cells apoptosis.