Follow-up of extended pterional orbital decompression in severe Graves' ophthalmopathy

Background. Compressive optic neuropathy (CON) with visual loss is, apart from corneal exposure and disfigurating proptosis, the most serious clinical sign encountered in Graves' ophthalmopathy. However, numerous different approaches and operative techniques have been proposed for orbital decompression, with varying results and side effects. The purpose of the present study was to analyze perioperative data and long-term results in patients with severe thyroid-related orbitopathy, treated by extended pterional orbital decompression, comparing its effectiveness to other procedures. Method. An extended pterional orbital decompression was performed in 42 consecutive patients (59 orbits) with severe thyroid-associated ophthalmopathy after failure of medical and radiation therapy during an 11-year period. Pre- and postoperative examination included visual acuity, Hertel exophthalmometry, ocular motility, visual fields (Goldmann perimetry) and notification of complications. Long-term evaluation was carried out on average at 11 months postoperatively (range 5-26 months). Findings. Visual acuity improved rapidly from a preoperative average of 0.53 +/- 0.33 (range, 0-1) to 0.77 +/- 0.31 (range, 0-1) postoperatively (p < 0.001). Worsening was not seen. An average reduction of proptosis of 3.79 +/- 2.32 min (range, 0.5-8 mm) was achieved with a mean preoperative Hertel measurement of 24.7 +/- 3.93 mm (range, 15-33 mm) (p < 0.001). Double vision and restriction of eye motility was present in 76.3% of patients preoperatively and improved in 63% of patients (p < 0.001). No new onsets of not already pre-existing double vision was seen. Complications included two cases of permanent palsy of the frontal branch of the facial nerve. Interpretation. The extended pterional orbital decompression improved vision and decreased proptosis and restriction of extra-ocular movements in patients with severe sight-threatening and disfiguring cases of Graves' orbitopathy and is still an effective and low-risk alternative to other non-neurosurgical operative techniques. Especially new developing postdecompression strabismus can be successfully avoided.