Amniotic membrane transplantation prior to glaucoma filtering surgery in a rabbit model

Abstract

Abstract: : Purpose: To evaluate the efficacy of amniotic membrane transplantation prior to glaucoma filtering surgery on the postoperative intraocular pressure (IOP) control in a rabbit model and examine the expression of cytokine and matrix metalloproteinases (MMPs) in the operated regions. Methods: A limbal–based conjunctival incision was made in the right eyes of 10 Japanese albino rabbits. Rabbit amniotic membrane (5X5 mm) was then sutured onto the sclera with 4 interrupted 9–0 nylon sutures. The incised conjunctiva was re–positioned with the same sutures. In the left eyes, only conunctival incisions with re–positioning sutures were done and used as controls. One week later, sclerectomy was performed in both eyes. Postoperative IOP and formation of filtering bleb were evaluated everyday for 1 week. The operated regions were examined with regard to the expression of cytokine (TGF–b) and gelatinases (MMP–2, 9) at 1 week postoperation. Results: IOPs were significantly lower in the eyes underwent sclerectomy with prior amniotic membrane transplantation between postoperative days 2 and 4. Moreover, the eyes with amniotic membrane transplantation showed better bleb formation with less conjunctival adhesion. Histologic examinations disclosed less subconjunctival inflammatory cell infiltration in the eyes with amniotic membrane transplantation.There was no significant difference in the expression of TGF–b in the operated regions between the two groups. However, the eyes with amniotic membrane transplantation showed lower expression of MMP–2 and MMP–9 than did the control eyes. Conclusions: Amniotic membrane transplantation prior to glaucoma filtering surgery is effective for reduction of IOP and its effectiveness may be attributable to the lower expression of MMPs.

Keywords: transplantation • intraocular pressure • cytokines/chemokines