[Posterior vitreous detachment induced by intravitreal injection of the combination of chondroitinase ABC and matrix metalloproteinase-3].
OBJECTIVE
To investigate the occurrence of enzymatic induction of posterior vitreous detachment (PVD) by the combination of Chondroitinase ABC (CA) and matrix metalloproteinase-3 (MMP-3), so as to seek a noninvasive and effective pharmacologic approach to facilitate and eventually replace the present mechanical vitreous surgery.


METHODS
Twenty-four pigmented rabbits were randomly assigned to two groups of twelve each, the experimental group was treated with CA (0.2 U) and MMP-3 (10 ng) combination, the control group was received equivalent dose of balanced salt solution (BSS). Clinical examinations and electroretinography were performed before and after injection. Over a different period of time, the rabbits were euthanized and killed and their eyes were examined histologically.


RESULTS
The foci of partial synchisis and clinically named PVD were recognized for the first time three days after injection. Complete liquefaction was found in every eye of experimental group, and in which, 5/8 eyes developed clinically detected PVD one week after injection Histologic section showed PVD with various extent in 3/7, 7/7, 7/7 eyes of experimental group 30 minutes, 60 minutes and one week after injection respectively, and complete PVD in 0/7, 1/7, 5/7 eyes of experimental group at the same periodic intervals as above. By contrast, no vitreous liquefaction was found and only one eye showed confined partial PVD in the control group. Clinic, electrophysiologic and histologic evaluation in all rabbits revealed no evidence of ocular toxicity.


CONCLUSIONS
Vitreous 1iquefaction and PVD can be produced shortly after intravitreal injection using a combination of CA and MMP-3, and the two enzymes were cooperative. Synchisis and weakening of vitreoretinal adherence were almost simultaneously. The dose of 0.2 U CA and 10 ng MMP-3 combination proved to be safe and ideal selection to induce PVD.
Meng
Zi-jun
ZJ
Department of Ophthalmology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430032, China. mongeon0319@hotmail.com
Zeng
Shui-qing
SQ
D000818:Animals; D019765:Chondroitin ABC Lyase / Q000009:adverse effects / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D019278:Matrix Metalloproteinase 3 / Q000009:adverse effects / Q000494:pharmacology*; D011817:Rabbits; D020255:Vitreous Detachment / Q000139:chemically induced* / Q000473:pathology
D019278:Matrix Metalloproteinase 3; D019765:Chondroitin ABC Lyase