Package and tissue patch implantation are common methods for repair of filtering bleb leaking after anti-glaucoma surgery.But the scarring or re-leakage of filtering bleb probably occur again.
This study was to investigate the repair effect of acellular dermal matrix (ADM) on filtering bleb leaking in rabbit model and compare the effectiveness among ADM, amniotic membrane and conjunctival overlap.
Trabeculectomy was performed on 48 eyes of 24 New Zealand rabbits, and models of filtering bleb leaking were established.The models were randomized into ADM group, amniotic membrane group and conjunctival covering group based on randomized number table.ADM patches with 4 mm×4 mm were implanted across lamellar cornea and sclera at a bridge in the ADM group, and the same size of amniotic membranes were used in the amniotic membrane group, and conjunctiva was sutured to limbus in the conjunctiva overlap group.The intraocular pressure (IOP) was measured before surgery and 1 day, 1 week, 1 month, 3 months and 6 months after surgery.The biocompatibility of materials above was assessed under the slit lamp microscope, and the status of filtering bleb was evaluated and compared with anterior segment optical coherent tomography (AS-OCT) 1 day, 1 week, 1 month, 3 months and 6 months after surgery.
Before surgery and 1 day, 1 week, 1 month, 3 months and 6 months after surgery, the IOP was (26.9±4.3), (16.6±5.1), (22.1±6.2), (18.3±6.5), (22.7±2.5), (23.4±1.4) mmHg in the AMD group, (29.9±5.4), (14.9±6.4), (21.6±7.8), (26.3±4.1), (26.0±4.2) and (23.0±5.3) mmHg in the amniotic membrane group, and (28.7±4.3), (15.7±7.0), (22.0±6.3), (28.2±4.1), (24.7±4.1), (23.0±2.7) mmHg in the conjunctival overlap group, showing significant differences among different groups and various time points (Fgroup=8.419, P=0.011; Ftime=15.543, P=0.000). The IOPs were significantly lower from 1 day through 3 months after operation than those before operation in the AMD group (P=0.000, 0.000, 0.006, 0.045); while the IOPs were reduced only from 1 day through 1 week after operation in comparison with before operation in the amniotic membrane group and the conjunctival overlap group (P=0.000, 0.001). One month after surgery, the IOPs were significantly declined in the ADM group compared with the amniotic membrane group and the conjunctival overlap group (P=0.001, 0.000). The grafts were clear under the slit lamp microscope and exhibited the valid filtering bleb until 3 months after operation under the AS-OCT in the ADM group.However, the valid filtering bleb remained only 1 month after surgery in the amniotic membrane group and the conjunctival overlap group.Neovascularization on the filtering bleb was found 3 months in the AMD group but 1 month in the amniotic membrane group and the conjunctival overlap group.
Compared with amniotic membrane and conjunctival tissue, ADM patch for the repair of filtering bleb leakage can increase the survival duration of filtering bleb and remain lower IOP.
Human acellular dermal matrix; Trabeculectomy/complication; Filtering blebs; Leakage; Repair; Amniotic membrane; Intraocular pressure; Rabbit