# The influence of high myopia-related exotropia on surgical dose–response in unilateral recession and resection surgery: a retrospective study

## TL;DR

This study found that high myopia affects surgical outcomes in exotropia surgery, with differences in resection doses between patients with and without high myopia.

## Contribution

The study reveals that high myopia influences surgical dose-response in exotropia surgery, particularly in medial rectus resection.

## Key findings

- Patients with high myopia had a significantly lower medial rectus resection dose compared to those without high myopia.
- Lateral rectus recession doses were not significantly different between high myopia and non-high myopia groups.
- Surgical doses correlated with horizontal deviation but not with axial length.

## Abstract

To investigate the impact of high myopia on the surgical dose–response in unilateral recession and resection (R&R) surgery for exotropia.

A retrospective analysis was conducted on 101 Chinese patients who underwent unilateral R&R surgery for concomitant exotropia between June 2021 and June 2024. Patients were divided into two groups based on axial length: those with high myopia (n = 38) and those without high myopia (n = 63). Surgical doses for lateral rectus (LR) recession and medial rectus (MR) resection were compared between the groups. Preoperative and postoperative deviations were measured, and statistical analyses were performed to assess the relationship between surgical dose, axial length (AL), and other clinical variables.

Age, duration of exotropia, and AL differed significantly between the groups, but other baseline characteristics were comparable. The LR recession dose did not differ significantly between the high myopia group (6.40 ± 1.11 mm) and the non-high myopia group (6.74 ± 1.00 mm, p > 0.05). However, the MR resection dose was significantly lower in the high myopia group (5.77 ± 1.02 mm) compared to the non-high myopia group (6.32 ± 0.92 mm, p < 0.05). The MR resection and LR recession dose was positively correlated with the horizontal deviation (p < 0.001), but showed no significant correlation with AL (p > 0.05).

Exotropia with high myopia had a greater surgical dose response than those without high myopia. No significant difference was found in LR recession dose, but the MR resection dose was significantly lower in the high myopia group.