More evidence linking inferior-medial wall orbital decompression with diplopia

This retrospective study found that inferior-medial wall orbital decompression is associated with a relatively high rate of new-onset diplopia of up to 33 percent.

The authors reviewed the charts of 51 patients with thyroid-related orbitopathy who underwent orbital floor and medial wall decompression at a single center between 1986 and 2007.

Patients with pre-existing diplopia were more likely to have persistent symptoms postoperatively and to require strabismus surgery after orbital decompression. Nearly half of the 29 patients who reported primary gaze diplopia preoperatively had persistent or worsened diplopia postoperatively, all of who required strabismus surgery. Five of the 15 patients with no primary gaze diplopia preoperatively had new-onset diplopia postoperatively, and only one patient required strabismus surgery.

Orbital decompression had a significant effect on horizontal ocular deviations with increasing esotropic shift. Primary position esotropia increased from 11.1 (± 22.5) PD preoperatively to 23.8 (± 20.5) PD after surgery (P = 0.01). There were no severe complications.

The authors write that patients who underwent inferior-medial wall decompression developed new-onset diplopia significantly more often? than patients who underwent inferior wall decompression alone.

They do not believe that lateral wall removal is superior to inferior/medial wall removal in regard to optic nerve decompression. However, they believe that lateral wall decompression may be associated with lower risk of new-onset primary or downgaze diplopia, as has been shown in previous studies.