·AIM:To observe the phenomenon of sensory layer apoptosis in detached retina,and further to study the apoptosis mechanisms providing the rationale for clinical treatment.·METHODS:Completely random design was applied.Forty healthy pigment rabbits without oculopathy were divided into 8 groups,1 hour,3 hours,1 day,3,7,14,28 days after retinal detachment(RD)and normal control,5 rabbits in each group.Right eye of each rabbit was treated with infusing sodium hyaluronate under retinal neuro-epithelium layer.The eyeballs were enucleated at different times after RD.The morphologic changes of the retina were observed by electron microscopes.Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL)technique was used to assess apoptosis.·RESULTS:There was cell apoptosis in sensory layer after detachment of retina,but almost not observed in retinas from control,14 days and 28 days eyes.They were abundant at 1 hour,3 hours,3 days,7 days after RD,peaked at 3 days,and dropped precipitously at 7 days after detachment.Every multiple comparison among the groups of 1 hour,3 hours,1 day,3 days and 7 days after RD showed significant difference in comparing of apoptotic cells(P<0.01).An obvious change of cell number was found comparing each of 1 hour,3 hours;3 days and 7 days with each of normal control,1 hour,1 day and 28 days(P<0.01).But there was no significant difference of multiple comparison among control group,1 hour,14 days and 28 days group after RD.·CONCLUSION:Apoptosis is an important mechanism of sensory layer cell degeneration after RD.·