An Empirical Study On Retinal Oxidative Damage Of Blue Light After Cataract Surgery In Rabbit Modle

Objective:Through establishing the experimental animal modle of blue light irradiated injury , Observation of retinal morphology and biochemical changes. To explore the role of blue light on the retina of oxidative damage after cataract surgery. To evaluate excellence and effectiveness of protection that effect on the physiological yellow lens in irradiation of retinal injury .Provide a theoretical basis of blue light filtrated IOL for the clinical application.Methods:65 New Zealand rabbits weighing 1.8 to 2.2kg were used .The animals were randomly divided into 4 groups:blank control(groupⅠ),only blue light irradiation(groupⅡ),without lens after phacoemulsification (groupⅢ),implantation of intraocular lens after phacoemulsification(groupⅣ).The phacoemulsification was performed in two eyes of groupⅢand groupⅣ.GroupⅣwith intraocular lens implantation .One month after operation ,afford blue light (1000±500Lux) irradiation on groupⅡ,Ⅲ,Ⅳfor 2 hours. Collecting specimens in Four different time: before light,24hours,48hours,5days after light .There are 5 rabbits in every time. To make retinal paraffin and ultrathin sections for light and electronic microscopy observation and analysis the changes in the thickness of the outer nucleus layer.. To evaluate the quantity of Total superoxide dismutase (T-SOD) Malondialdehyde (MDA), Glutathione peroxidase(GSH-PX) in Retinal tissue. The data were analyzed statistically by SPSS12.0 for window.Result: ( l ) Light microscope: Normal group have clear layers of retinal structure .The inner and outer segments were in neat and orderly arrangement,and the outer nucleus layer(ONL) arranged sequence, stained evenly. Morphological changes of receptors appeared after light exposure and deteriorated gradually along with the progression of light exposure. The outer nuclear layer became thinner and sparser. (2)Electronic microscopy:The outer segments of optic rods of photoreceptors arranged in a confused order, the structure of membranous disks disorganized. Meanwhile, the outer segments of optic rods of photoreceptors in groupⅡwas found no serious changes. (3)Analyzing the thickness of the outer nucleus layer in each group via Photo Analysis System, we found that no significant difference of the thickness changes in the outer nucleus layer between groupⅠand each group before light exposure(F=2.84 ,P>0.05);ONL was reduced in each group deteriorated gradually along with the progression of light exposure.(P<0.01). and had a significant difference between and groupⅡ,ⅢandⅣ(p<0.01); (4)There are no significant difference of SOD,MDA,GSH-PX between groupⅠand each group before light exposure(F= 2.58,2.37,2.46 ,P>0.05).The activity of SOD and GSH-PX was reduced in each group deteriorated gradually along with the progression of light exposure (P<0.01).The content of MDA increase dramatically as light exposure time prolonged (P<0.01). There had a significant difference between andⅡ,ⅢandⅣ(p<0.01) in every spots after light exposure; There are no significant difference of SOD,MDA,GSH-PX between groupⅢandⅣ.Conclusion: Blue light of low-intensity and short-term after cataract surgery in rabbit modle can reduce oxidative damage of retinal. Physiological yellow lens decrease irr- adiation of retinal injury caused by blue light. UV-filtering intraocular lens did not have this function.