Changes in pupillary distance after fat versus bony orbital decompression in Graves’ orbitopathy

Objective To report changes in pupillary distance (PD) after orbital decompression in patients with Graves’ orbitopathy (GO). Design Retrospective comparative case series. Participants A total of 59 cases who underwent the same type of orbital decompression on both eyes. Methods The medical records of 111 patients who underwent orbital decompression were reviewed retrospectively. Fifty-nine patients without restrictive myopathy who underwent the same procedure on both eyes were included. Patients were divided into the following 3 groups by procedure: only fat decompression (group 1, n = 18), fat and medial wall decompression (group 2, n = 11), and fat, medial, and inferior wall decompression (group 3, n = 30). Preoperative and postoperative PD and proptosis were measured. Results PD shortened by 2.9 mm in group 1 (p < 0.001), 2.4 mm in group 2 (p < 0.001), and 3.5 mm in group 3 (p < 0.001). Proptosis improved by 3.5 mm in group 1 (p < 0.001), 3.5 mm in group 2 (p < 0.001), and 4.6 mm in group 3 (p < 0.001). PD changes were not significantly different between the groups (p = 0.328). The change in PD was significantly correlated with the mean amount of proptosis reduction (r = 0.374, p = 0.003). Conclusions PD shortened after orbital decompression in patients with fat proliferative GO. The change in PD was not related to the type of orbital decompression, but rather to the amount of proptosis reduction. Postoperative changes in PD should be considered when performing orbital decompression.