Abstract
Purpose: :
To describe an ex vivo experimental model of adjustable suture on the flap of trabeculectomy using a slip-knot.
Methods: :
Trabeculectomy was performed in fifteen freshly excised pig eyeballs. A conventional 10.0 mononylon suture was performed on the scleral flap's first corner. The second suture, in a crossover fashion, was randomly chosen between a slip-knot suture (study group) and a conventional suture (control group). Water column technique was used to measure the intraocular pressure (IOP) in three different time points: first, when the knot was tightened; second, when the adjustable knot was loosened (study group) or the conventional knot was removed (control group); third, when the slip-knot was re-tightened or five minutes after the second measurement in the control group. Adjustable knot had to be loosened and re-tightened from its corneal ends without touching the sclera or scleral flap. IOP variations and mean IOP values were compared between control and study group at the three different time points. A mixed linear model was used to evaluate intra and inter-group mean IOP differences.
Results: :
In the control group, the mean baseline IOP (cm H2O) was 26.8±0.8, decreased to 12.6±4.25 at the second time point (p<0.01) and kept stable at the third time point (12.2 ± 4.0). In the study group, the mean IOP baseline was 26.8±0.9, decreased to 16.3±2.3 at the second time point (p<0.01), and returned to initial values (26.4±1.7) at the third time point (time1 vs time 3; p=0.31).
Conclusions: :
This ex vivo experimental model of adjustable suture using a tuning slip-knot on the flap of trabeculectomy showed an effective tightening and loosening and re-tightening suture mechanism in porcine eyes. This new technique may represent a potential improvement in the postoperative pressure control of glaucoma filtration surgery.
Keywords: intraocular pressure • outflow: trabecular meshwork • anterior segment