Objective: To study the effect of Vaccinium uliginosum (VU) on the electroretinogram (ERG) and retinal pathological changes in rabbits after light-induced damage.
Methods: Twenty-eight Chinchilla rabbits were randomly divided into four groups: administrated beforehand (A), administrated after injury (B), light injury without administration (C) and blank group (D). After 4 weeks administrating group A with VU homogenate at 4.8 g/(kg·d) once a day, electroretinogram (ERG) of group A, B and C was recorded according to the standards set by the International Society for Clinical Electrophysiology of Vision (ISCEV). Then they were exposed to strong light except for group D. Just after that group A was stopped being fed with VU, and group B was started to be fed with it. Then ERG of all groups was recorded after 1 day, 1 week and 2 weeks respectively. Throughout the whole process groups which weren’t fed with VU were fed with normal saline. Finally the tissues & structures of all the groups were observed and the thickness of outer nuclear layers (ONL) was measured.
Results: (1) After four weeks feeding with VU, the latency time of ERG in group A got shorter than others, and the amplitude got increased. After being exposed to strong light latency time lengthened and amplitude decreased in all the injury groups, but compared at each same moment the measured values in group A were better than group C. With the accumulation of VU the ERG in group B was improving and all of the detected values were better than group C at last. (2) Retina in group D was normal in histology and layers were in order. But those in group C got disarranged. Injury of group A and B was minor than group C. The thickness of ONL in group C was significantly thinner than others’ (all P=0.000), and that in group A and B was thicker than group C but thinner than group D. That in group A was thicker than group B.
Conclusions: (1) VU can relieve the harm of the rabbits’ retina exposed to normal day and night rhythm. (2) VU can relieve the harm of light when used beforehand. (3) VU can repair the light damage to retina. |