Evaluation of Scleral Adjustment Method: A Novel Adjustable Suture Technique in Strabismus Surgery

To determine whether passing a pole suture through the sclera at two points provides fixation comparable to that of a sliding noose, we measured the tensile strength of the suture‒sclera interface during simulated traction. In this in vitro study, three suture patterns were evaluated in porcine eyeballs, using 6-0 polyglycolic acid sutures. Patterns A (control), B (second suture pass perpendicular), and C (second suture pass in the same direction) were compared. The tensile strength of each pattern was measured 20 times using a KANON TK300CN, and the results were analyzed using the Kruskal‒Wallis test. Pattern A showed a tensile strength of 2±4 gram-force (gf) (range: 0-12). Pattern B showed 112±38 gf (range: 61-184). Pattern C showed 139±31 gf (range: 97-204). Patterns B and C had significantly higher tensile strengths than Pattern A (p<0.001). Although Pattern C was not significantly different from Pattern B (p=0.363), it exhibited the highest tensile strength. Lifting the suture between the first and second suture passes allows for an adjustable suture length, suggesting that adjustability can be achieved using only the sclera. This scleral adjustment method with a second suture pass offers a durable means of securing extraocular muscles and may represent a valuable addition to adjustable suturing techniques.