Efficacy of collagen matrix implant on adhesions in restrictive strabismus: An experimental study in a rabbit model

Abstract

Purpose: To determine the efficacy of a biodegradable collagen matrix implant (Ologen, Aeon Astron Europe BV, Leiden, the Netherlands) in reducing adhesions in a rabbit model of restrictive strabismus. Methods: A prospective, masked-observer, controlled experimental study was performed. Sixty superior rectus muscles of 30 rabbits were resected and Marlex mesh was fixed beneath the resected muscle using nonabsorbable suture. Forty eyes underwent one of two different procedures; the resected muscle was wrapped with preserved human amniotic membrane (AM group) or Ologen (Ologen group). Randomly selected 20 eyes served as controls. Eyes were enucleated at 4 weeks after surgery to measure the severity of adhesion using a push pull gauge. Histopathological examination was performed. Results: At postoperative week four, the average tensile strength of the myoscleral adhesion was significantly lower in the Ologen group (151.8 ± 42.7 gram force) compared to controls (347.9 ± 68.6 gram force) and AM group (193.0 ± 44.3 gram force) (p < 0.001 and p = 0.045, respectively). Ologen group showed significantly lower degree of acute inflammation, chronic inflammation and rectus muscle fibrosis compared with controls (all p < 0.01). The degree of chronic inflammation was significantly lower in the Ologen group compared with AM group (p = 0.012). Conclusion: Compared to amniotic membrane, Ologen is more effective in reducing mesh-related extraocular muscle adhesions in a rabbit model of restrictive strabismus.