The Effect of Rim-off Deep Lateral Orbital Decompression on the Lateral Rectus Shape and Oculomotor Balance

Purpose: – To measure the effect of rim-off deep lateral decompression for Graves orbitopathy on the lateral rectus muscle path and oculomotor balance. Methods: – Retrospective analysis of the medical records and pre- and postoperative computed tomography scans of 34 orbits of 23 patients who underwent deep lateral decompression alone. The oculomotor balance of these 23 patients was measured with the alternate cover test and prisms before and after surgery. Bezier functions were used to measure the postoperative path of the lateral rectus in all decompressed orbits. Results: – Deep lateral decompression induced a curvilinear deformation of the lateral rectus. There was no significant correlation between the position of the point of maximum muscle displacement and the size of the residual lateral wall. The changes in the lateral rectus path had no adverse effects on the oculomotor balance of the patients. Conclusions: – The location of the curvilinear deformation of the lateral rectus do not depends on the residual segment of the lateral wall. The changes of the lateral rectus path have no deleterious effect on the oculomotor balance.