Abstract
Purpose: :
To investigate and characterize the reaction of the subconjunctival tissue to the biodegradable implant ologen (Aeon Astron Corporation, Taipei, Taiwan) in glaucoma surgery.
Methods: :
Ologen matrices and scar tissue were explanted in revision surgery in case of failed glaucoma surgery after trabeculectomy (TE; 2 cases) or after glaucoma drainage device (GDD; 2 cases) surgery. Histological sections were studied by hematoxylin-eosin (HE) staining. Further immunohistochemic stainings were performed for α-smooth muscle actin (α-SMA), fibronectin (FN), collagen III (COL3) and CD68.
Results: :
HE stainings of ologen implants after TE revealed an invasion of fibroblasts into the implant. The implants were enclosed by a collagenous pseudocapsule and surrounded by a loose connective tissue. α-SMA staining showed an accumulation of myofibroblasts predominantly in the ologen implant, whereas COL3 was mainly detected at the border area of the implant and the pseudocapsule around the implant. Immunohistochemistry for FN showed an intensive staining inside the implant and at the pseudocapsule.In case of ologen implants after GDD sugery a pseudocapsule of three layers of different density was found. Staining for α-SMA indicated an acummulation of myofibroblasts in the middle layer of the pseudocapsule and in the ologen implant. Staining for COL3 showed no signal in the inner layer (next to GDD), however, a strong staining in middle and outer layer, and a weak signal inside the ologen. FN was detected with a very strong signal in the implant and in the inner layer of the pseudocapsule. Staining for CD68 revealed macrophage activity inside the ologen implant.
Conclusions: :
Ologen implants seem to induce the expression of FN and α-SMA. Inside the ologen implant macrophage activity was shown. The subconjunctival tissue responds to the implantation of an ologen implant with a scarring reaction.
Clinical Trial: :
http://www.clinicaltrials.gov NCT01174420
Keywords: wound healing • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • immunohistochemistry