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Bacterial collagenase. Proposed adjunct to vitrectomy with membranectomy
Abstract:
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 Müller'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.
Insights
Clostridiopeptidase A effectively digested preretinal scar tissue in rabbits without harming the retina. Prompt removal via vitrectomy ensured normal retinal function and morphology, suggesting a novel approach for vitrectomy.
Area of Science:
- Ophthalmology
- Enzyme therapy
- Retinal surgery
Background:
- Preretinal scarring can impair vision and complicate vitreoretinal surgery.
- Current surgical techniques for scar removal carry risks of retinal damage.
Purpose of the Study:
- To evaluate the efficacy and safety of Clostridiopeptidase A (collagenase) for digesting preretinal scar tissue.
- To assess the enzyme's impact on retinal structures and function.
Main Methods:
- Enzymatic digestion of preretinal cicatricial tissue in rabbit eyes using purified Clostridiopeptidase A.
- Light and transmission electron microscopy to examine retinal morphology.
- Assessment of retinal function via electroretinograms post-vitrectomy.
Main Results:
- Clostridiopeptidase A digested preretinal scar tissue within 30 minutes without altering normal retinal morphology.
- Enzyme removal by vitrectomy at 48 hours post-injection resulted in normal electroretinograms and retinal structure.
- Prolonged enzyme exposure (24 hours) led to adverse effects including lens opacities and hemorrhage.
Conclusions:
- Purified Clostridiopeptidase A demonstrates specific collagenase activity against vitreal scar tissue.
- This enzyme holds potential as a novel adjunct to vitrectomy for scar removal, minimizing retinal damage.