Bacterial collagenase. Proposed adjunct to vitrectomy with membranectomy
L. C. Moorhead, D. A. Redburn, D. S. Kirkpatrick and F. Kretzer
Clostridiopeptidase A digested preretinal cicatricial tissue without
causing morphological alteration of normal retina during a 30-minute
incubation in the rabbit. Light and transmission electron microscopy were
used to determine effects on the inner limiting membrane and retinal
ganglion and Muller's cells and to evaluate enzyme digestion of preretinal
scarring. Removal of the injected collangenase by vitrectomy resulted in
normal electroretinograms and retinal morphology 48 hours postoperatively.
If the enzyme was left in the eye for 24 hours, lens opacities, partial
erosion of the inner limiting membrane, and extensive hemorrhage resulted.
The specificity of action of the collagenase is due to the high degree of
purity of the enzyme used and a substantial biochemical difference between
scar collagen and basement membrane collagen. The injection of purified
collagenase capable of digesting vitreal scar tissue while leaving the
retina undamaged could represent a new approach to vitrectomy, specifically
to facilitate certain cases of membranectomy.