Animals ; Epilepsy ; drug therapy ; physiopathology ; Hippocampus ; physiopathology ; Long-Term Potentiation ; Male ; Maze Learning ; drug effects ; Phytotherapy ; Pyrazines ; pharmacology ; therapeutic use ; Rats ; Rats, Sprague-Dawley

Background Intravitreal injection of triamcinolone acetonide (TA) can effectively eliminate central vein occlusion macular edema and improve visual acuity, and photopic negative response (PhNR) can reflect the inner retinal function of RGCs and their axons. It is possible there is a correlation between these two observations.Objective This study was to evaluate the changes of PhNR of flash electroretinogram (F-ERG) after intravitreal injection of TA for macular edema in central retinal vein occlusion ( CRVO ). Methods Thirteen eyes of 12 patients with macular edema caused by CRVO received an injection of 0. 1 ml (4 rg) of TA. PhNR,visual acuity and retinal thickness of macular area were assessed with Roland RETI scan 3. 15 system,decimal visual chart and Stratus optical coherence tomography (OCT) before and 4 weeks after the administration of TA. Written informed consent was obtained from each subject before any medical procedure. Results Visual acuity was improved in 12 eyes and stable in 1 eye 4 weeks following the intravitreal injection of TA. OCT showed that the retinal thickness of the macular area was reduced ;meanwhile,elevation of the amplitude of PhNR also was seen in the F-ERG after the administration of TA in comparison with before the administration of TA. The calculated results determined that the visual acuities were 0. 32t0. 12 and 0. 48±0. 09 (t=6. 325 ,P=0. 000) ,and the retinal thickness values of the macular area were (459.46± 131.31 ) μm and ( 297.54 ±43.31 ) μm ( t = 5.961, P = 0. 000 ), and the average amplitude of PhNR were ( 80. 23±22.96 ) μV and (61.28 ±20. 16 ) μV ( t = 4. 438, P = 0. 001 ) before and after the intravitreal injection of TA, respectively,showing significant differences. No significant correlation was found between PhNR amplitude and retinal thickness of the macular area both before and after the administration of TA ( before: r = 0. 587, P = 0. 035; after:r=-0. 011 ,P = 0. 971 ). Conclusion PhNR can be used for evaluating the status of inner retina after intravitreal injection of TA for macular edema of CRVO.