Reduction in Rectus Muscle Recession Depending on the Distance Between Rectus Muscle Suture Placement and Scleral Insertion in Rabbit Eyes.

PURPOSE

To quantitatively determine how a large tendon remnant reduces the effect of the rectus muscle recession procedure with respect to the distance between the placement of the muscle suture and the scleral insertion.

METHODS

Thirty-six eyes from 18 rabbits were randomly divided into four groups according to the distance between the superior rectus muscle suture placement and the scleral insertion (1, 2, 3, and 4 mm). The superior rectus muscle was sutured at the previously listed distances from the insertion. Each superior rectus muscle was reattached using a scleral pass at a site 4 mm posterior to its original insertion. The amount of recession was measured as the distance between the most anterior aspect of the reattached muscle and the original insertion site.

RESULTS

The mean amount of recession was 4.07 ± 0.25 mm in the 1-mm group and 2.76 ± 0.55 mm in the 4-mm group at postoperative week 4. There were significant differences in the amount of recession between the four groups. Linear regression analyses revealed a significant relationship between the distance of the muscle suture placement from the scleral insertion and the amount of recession (r(2) = 0.521). The superior rectus muscle was estimated to be reattached 0.437 mm anterior to the desired location for every 1 mm that the muscle suture was placed posterior to the scleral insertion.

CONCLUSIONS

The potential error that depends on the distance between the muscle suture placement and the scleral insertion should be considered to reduce undercorrection and ensure a good surgical outcome.