Effects of vitreous hemorrhage on the retina in rabbits / 眼科新进展

ABSTRACT

Objective To investigate the changes in electroretinography (ERG) and ultrastructure of the retina after experimental vitreous hemorrhage in different phases in rabbits so as to provide experimental evidence for the treatment and prognosis.Methods The autologous blood of 0.2 mL was intravitreally injected in the right eyes of 32 New Zealand white rabbits for the establishment of vitreous hemorrhage model,with the left eyes as controls.All rabbits were randomly divided into 4 groups,and one group was selected on day 3,7,14 and 30 after injection for routine examination and Flash ERG.The rabbits were sacrificed for obtaining the specimens of eyeballs,which were used to observe the ultrastmcture of retina.Results The ERG waves,which become undetectable after experimental vitreous hemorrhage,and gradually appeared 7 days later.The amplitudes of ERG-a waves and b waves of the experimental eyes both were significantly lower than those of the control groups 3 days after injection in brightflash light conditions (both P ＜ 0.01).The ERG-a waves recovered 30 days after injection,which showed no significant difference from the control group (P ＞ 0.05),but had a statistically significant difference when compared with those on day 14 (P ＜ 0.05).The ERG-b waves began to rise 7 days after injection,which has no significant difference from the control group (P ＞ 0.05),but statistically significant difference when compared with those on day 3 (P ＜0.05),and were close to the normal amplitude on day 14 and day 30 after injection.Scanning electron microscopy results showed that no posterior vitreous detachment (PVD) was appeared 3 days after injection,but the partial PVD appeared in 1 of the 8 eyes,complete PVD in 1 of 8 eyes on day 7;partial PVD in 2 of 8 eyes and complete PVD in 5 of 8 eyes on day 14;partial PVD in 1 of 8 eyes and complete PVD in 7 of 8 eyes on day 30.No PVD was observed at each stage in the control eyes.Conclusion Approximately 1 week after vitreous hemorrhage,retinal function is mildly and reversibly involved,and PVD formation appears,which can provide a reference for judgment on the changes in retinal function after clinical and experimental vitreous hemorrhage and selection of time window for clinical vitreous surgery.