Research On The Comparision Of F-ERG,Mf-ERG,F-VEP Of PDR Between Pre-and Post-Argonlaser PRP

Object: The main purpose of this paper is to know how of the histological change of retina caused by argon laser and the theory of argon laser photocoagulation. So, through synthetically analyzing the melioration of blood and oxygen supplied to retina and the affect on the function of retina caused by photocoagulation, it is expected to supply some important data for objectively evaluating the effect of photocoagulation.Methods: 45 eyes are diagnosed as III-IV DR (not treated by photocoagulation and no other eyeground diseases) . These eyes are checked respectively by F-ERG, Mf-ERG, F-VEP before and after photocoagulation a month later. All of the data are analyzed by the statistics. Here, T-test is chosen to do this.Results: 1. For F-ERG, there is a remarkable difference of the amplitude of wave a and wave b comparing before photocoagulation with after photocoagulation ( p< 0.01 ) . On the contrary, the Peak Value t is not (p>0.05) .2. For F-VEP, the amplitude and delitescence of wave p does not change greatly (p>0.05) .3. For Mf-ERG, The different absolute values of responding density of wave N₁ and P₁ in photocoagulating retina area and 5° area in the center of yellow spot compared between before photocoagulation and after photocoagulation have statically statistical meaning (P<0.01) . The absolute values of responding density after photocoagulation decreased greatly. But the delitescences do not have the phenomena (P >0.05) . And the differences between responding density of wave N₁ and P₁ in photocoagulating retina area and 5° area in the center of yellow spothave statically statistical meaning (P<0.01) .Conclusion: l.The amplitude of wave a and wave b photocoagulation after photocoagulation decreased greatly. By using argon laser photocoagulation, the light receptors and ambicells or Muller cells are torn down. So, the amount of oxygen and blood supplied to retina is decreased. Generally speaking, the development of DR is stopped. There is no obvious change in the peak time of wave a and wave b compared between before and after photocoagulation. So, the laser treatment decreases the amount of light sensors without affecting the speed of passing the sight information.2. The amplitude and delitescence of wave P and wave N do not change greatly before and after photocoagulation. Argon laser photocoagulation can not do harm to the nerve fibers. So, it is proved that argon laser photocoagulation is safe for treating DR.3. The absolute values of responding density of wave Ni and P! in photocoagulating retina area and 5° area in the center of yellow spot after photocoagulation decreased greatly. The decreasement of every wave in 5° area in the center of yellow spot is less than the one in the photocoagulating area. When argon laser photocoagulation takes affect on the area outside the yellow spot, it also disables the function of the area inside the yellow spot.