The difference in muscle slippage according to scleral suture techniques in rectus muscle resection of rabbit eyes

Purposes: To investigate the degree of muscle slippage according to scleral suture techniques in extraocular muscle resection of rabbit eyes. Methods: Twenty eyes from 10 rabbits (20 superior rectus muscles) were divided into four groups according to scleral suture techniques. The types of scleral suture technique used for the four groups were as follows: group 1 - double-arm mattress suture technique without midline suture; group 2 - double-arm mattress suture technique with midline suture; group 3 - long scleral tunnel suture technique without midline suture; and group 4 - long scleral tunnel suture technique with midline suture. Five superior rectus muscles were assigned to each group and they underwent resection with 6-0 prolene using one of the four suture techniques. The degree of muscle slippage was measured 3 months after the surgery, defined as the distance between the prolene materials at the centre of muscle insertion and the pre-placement suture. Results: The mean degree of muscle slippage for treatment groups 1-4 was 2.3 ± 0.62, 1.0 ± 0.27, 1.5 ± 0.45, 0.5 ± 0.46 mm respectively. Group 1 had significantly more muscle slippage than groups 2-4 (P = 0.006, P = 0.046, P = 0.001 respectively). Group 4 had the least slippage among the four groups, while group 3 had significantly more slippage than group 4 (P = 0.009). The differences between groups 2 and 3 and between groups 2 and 4 were not statistically significant (P = 0.083, P = 0.077 respectively). Conclusion: Long scleral suture technique is more effective method than double-arm mattress suture technique for the prevention of muscle slippage in rectus muscle resection. The addition of a midline suture of rectus muscle was helpful in the prevention of muscle slippage.