Is incidence of diplopia after fat removal orbital decompression a predictive factor of choice of surgical technique for Graves' ophthalmopathy?

Dysthroid orbitopathy or Graves ophthalmopathy is a frequent pathologic condition five times more frequent in females than males. The main symptoms are : proptosis, motility disorders related to eye muscles fibrosis, eyelid retraction, lagophthalmos, and finally the more severe ones : compressive optic neuropathy at the apex of the orbit, and corneal exposure. In order to reduce proptosis the classic approach is Bone Removal Orbital Decompression (BROD) either through eyelid skin, coronal, conjunctival, or endonasal approaches. Recently a new technique has beeen described by Olivari: Fat Removal Orbital Decompression (FROD). The purpose is to evaluate the incidence of diplopia after FROD and improve surgical indications for Graves' ophthalmopathy. Material and methods : 35 patients were included in this retrospective study (58 orbits). FROD (OLIVARI technique) was performed in all cases (23 bilateral surgery, 12 unilateral; 12 men, 23 women). All patients with optic neuropathy (severe Graves' ophthalmopathy) were eliminated because bone decompression was always performed. The ocular motility was examinated before and after surgery by orthoptic screening The average follow up was 18 months. Results and discussion : before FROD, 7 patients complained of moderate or severe diplopia: all remained with diplopia after FROD. After FROD 32% developped a new diplopia : only one patient remained with diplopia after strabismus surgery or adaptation by prisms glasses. Diplopia after BROD in moderate Graves' ophthalmopathy (with indications identical to our study) is reported from 23 to 34% in previous studies. Conclusion : diplopia after FROD is a real risk whose incidence is identical after FROD and BROD and must be explained to each patient before surgical decision.