title: Extraocular muscle regeneration in freeze-treated extraocular muscle autografts.
abstract: New growth of extraocular muscle has been demonstrated in degenerating peripheral nerve autografts implanted between two extraocular muscles. This suggests that extraocular muscle may be lengthened for therapeutic purposes if a suitable matrix can be found to support this new growth. Investigators of peripheral nerve regeneration have found that the basal lamina of freeze-killed skeletal muscle remains intact and supports axonal regeneration. This study was designed to investigate the feasibility of inducing regenerative growth of extraocular muscle in freeze-treated extraocular muscle autografts. In six beagles the inferior oblique muscle was removed from both orbits, frozen in liquid nitrogen, and allowed to thaw at room temperature. The freeze-thaw cycle was repeated. The freeze-treated grafts were then sewn in an end-to-end fashion between the cut end of the lateral rectus and the globe. At both 4 and 8 weeks postoperatively, three dogs were killed, and the grafts were removed from both orbits. These were prepared for light and electron microscopic examination. This revealed robust growth of mature-appearing, innervated muscle fibers in the proximal graft that could be differentiated by adenosine triphosphatase histochemistry. Rare, immature fibers were seen in the distal graft. These results demonstrate that freeze-treated extraocular muscle autografts support regenerative growth of extraocular muscle.
authors.affiliation: Department of Ophthalmology, University of Kentucky, Lexington.
authors.forename: S P
authors.initials: SP
authors.lastname: Christiansen
authors.forename: R S
authors.initials: RS
authors.lastname: Baker
authors.forename: M
authors.initials: M
authors.lastname: Madhat
mesh_terms: D000818:Animals; D004285:Dogs; D005260:Female; D005615:Freezing; D009801:Oculomotor Muscles / Q000502:physiology* / Q000637:transplantation / Q000648:ultrastructure; D012038:Regeneration / Q000502:physiology*; D014182:Transplantation, Autologous