Abstract
Purpose::
To assess the effectiveness of a bioengineered, biodegradable implant, OculusGen, in preventing poor bleb formation and flat anterior chamber after trabeculectomy in eyes with a surgical wound defect.
Methods::
The right eyes of 30 female New Zealand albino rabbits weighing 2.5 to 3.5 kg underwent trabeculectomy with a porous, degradable, bioengineered, collagen-glycoaminosglycan matrix (OculusGen) implanted on top of the scleral flap subconjunctivally, while the left eyes received no procedure to serve as a control group. A 1-2 mm circular conjunctival defect was created. Tenonectomy was not performed and antifibrotic agents were not used. Six rabbits were sacrificed on days 3, 5, 7, 21, and 28. Goldmann applanation tonometry, Seidel test and conjunctival defect measurement were performed. Exenteration was performed and the tissue prepared in 4% formaldehyde, hematoxylin and eosin (H&E) for general histological observation, and Sirius and Fast-green stains to assess collagen deposition and cell migration. Additional tissue sections were used for alpha-smooth muscle actin (SMA) immunocytochemistry to identify the distribution of myofibroblasts and the maturity of the wound.
Results::
Seidel tests were negative for all operated eyes even at the early conjunctival defect stage. No flat anterior chamber occurred. The mean IOP was 7.4 ± 2.0 mmHg at day 3, 7.4±2.3 mmHg at day 5, 8.8±1.4 mmHg at day 7, 8.3±1.4mmHg at day 14, 8.2±1.5 mmHg at day 21, 8.3±2.3 mmHg at day 28. The average sizes of the conjunctival defect were 1.77±1.41 at day 3, 0.96±0.93 mm2 at day 5, 0.20±0.50 at day7. Histology showed randomized collagen deposition and microcyst formation in the bleb after the matrix had degraded completely at day 28. (Sirius and Fast green stain).
Conclusions::
OculusGen successfully serves as a 3-dimensional scaffold for cell migration and proliferation and can prevent the anterior chamber from collapsing after trabeculectomy in the presence of a large wound defect. It might also be successful at repairing postoperative bleb leaks.