Comparison of surgical dose response between divergence insufficiency esotropia and non-accommodative esotropia without divergence insufficiency

Abstract

Background The study compared the surgical dose-response relationship for divergence insufficiency esotropia (DIE) and non-accommodative esotropia without divergence insufficiency (non-DIE). Methods We carried out a retrospective review of a group of patients with DIE and non-DIE who underwent recession surgery of the medial rectus muscle in both eyes. Linear regression analysis compared surgical dose–response between the two groups. Results In the 15 patients with DIE, the mean preoperative ocular deviation at distant fixation was 25 prism diopters (PD), compared with 3 PD postoperatively. In the 38 non-DIE patients, the mean preoperative ocular deviation was 28 PD, compared with 3 PD postoperatively. The average surgical dose–response was 1.56 PD/mm in the DIE group and 2.91 PD/mm in the non-DIE group ( p < 0.001). Conclusions Surgical dose–response was significantly lower in DIE patients than in non-DIE patients. Augmented MR recession surgery could be regarded as an effective treatment option for patients with DIE. Further study with a larger sample and long-term follow-up is needed to seek the proper extent of surgery in these patients.