Stability and effects of muscle transplantation for very large angle esotropia: A study of 22 patients

Abstract

Purpose: A very large angle esotropia is characterized by an angle more than 80 prism diopters (pd). A single eye surgery would not correct such a large angle. Supramaximal recessions and resection would lead to restriction of ocular motility. We present a series of 22 patients with large angle esotropia treated with muscle transplantation.

Methods: A total of 22 patients (14 males and 8 females) were included in the study. All the patients had a minimum of 80 base out deviation in primary position. All patients underwent thorough preoperative orthoptic checkup and refraction. The patients were followed up on day 1, day 30, at 6 months, at 1 year, and 2 years. All the patients underwent standard muscle transplantation, where the resected extra stump of lateral rectus was transplanted to the medial rectus using 6-0 prolene which was recessed by a standard recession technique.

Results: The mean age of the 22 patients was 32.21 ± 13.1 years. The mean preoperative angle was 92.4 ± 13.5 pd base out. The mean postoperative angle at 2-year follow-up was 12.3 ± 9.9 pd. The average correction achieved per mm was 4.1 ± 0.3 pd. The adduction restriction was <1 in all the patients at the end of 2 years except one patient. The abduction was normal in all the patients.

Conclusion: The true muscle transplantation is a safe alternate option for large angle esotropia when uniocular surgery is desired. The surgical results are stable in long-term and therefore a viable option.

Figure 1

Schematic diagrams representing the muscle transplantation (a), the hang back recession (b) and the conventional recession or the long-term result of hang back recession (c). It is important to understand here that the segment used (a) could be the muscle segment or any expander

Figure 2

The photographs show the preoperative (a), the immediate postoperative (b), and the later postoperative motility of the operated eye. Note that the motility (c) is very good in the left eye (muscle transplantation) postsurgery

Figure 3

The photographs show another large angle esotropia. The preoperative (a) the immediate postoperative (b) and the late postoperative motility of the operated right eye. Note that the motility (c) in the right eye after the muscle transplantation surgery

Figure 4

(a) The preoperative large angle esotropia, (b) the excellent correction in primary position