AIM: To investigate the ultrastructure of the basal vitreo- retina interface in enucleated pig eyes after vitreous injection of enzymes.

METHODS:Totally 130 eyes were obtained from freshly slaughter pigs and divided into 5 groups. Each group was sub-divided into the 15 minutes group and the 30 minutes group, with 13 eyes in each group. The control group were performed middle vitreous injection of 0.1mL PBS, 200U/mL and 800U/mL hyaluronidase(HA)were injected in groups A and B, 10U/mL and 50U/mL chondroitinase(CA)in groups C and D. After incubation for 15 minutes and 30 minutes, the eye balls were fixed with 4% glutaraldehyde and retina fixative solution. Pathological examination, eosin-hematoxylin staining, scan electron microscopy were taken to evaluate the remaining vitreous on vitreous base, transmission electron microscopy to evaluate retina toxicity.

RESULTS:Both of gross appearance and hematoxylin+eosine slice all revealed basal vitreous partially liquefied and degradation. Remarkably decrease was found in basal vitreous than the control group both in the HA 800U/mL group and the CA 50U/mL group when using electron microscopy scanning. Transmission electron microscopy in group B, C and D revealed the remaining vitreous were less than the control group.

CONCLUSION: Both CA and HA can cause basal vitreoretinal detachment in enucleated pig eyes. But the HA may cause less damage to the retina.