Long-term follow-up of patients with thyroid eye disease treated with endoscopic orbital decompression

To evaluate the outcome of endoscopic decompression in a series of patients with thyroid eye disease.

All 46 patients operated at our institution in the period 2001 to 2011 were invited for re-examination. Thirty-seven patients were included in the study and underwent a general otorhinolaryngological and ophthalmological examination. Nasal endoscopy, autoperimetry and a CT scan of the orbits and paranasal sinuses were performed. Preoperative and early postoperative data were obtained from hospital records. Re-examination was performed from 12 months to 9 years postoperatively. Paired t-test was used to evaluate the change in pre- and postoperative data. Image-guided surgery was used in two patients.

Visual acuity improved from a median value (range) of 0.8 (0.05-1.25) to 1.0 (0.4-1.25) (p=0.006). Intra-ocular pressure (IOP) was reduced from a median value (range) of 18 mmHg (10-27 mmHg) to 14 mmHg (8-24 mmHg) (p<0.001). Median (range) Hertel values were 22.5 mm (14-29 mm) preoperatively and 19 mm (11-26 mm) postoperatively (p<0.001). Mean reduction in proptosis was 4.0 mm. At follow-up, visual fields were normal in 16/37 patients (43%) and with small defects in 12/37 patients (32%). Seventeen patients (46%) had diplopia preoperatively in one or more directions of gaze while 9 (24%) suffered from constant diplopia. After endoscopic decompression, new onset diplopia was seen in seven (19%) individuals, while worsening of diplopia occurred in eight (22%). Impaired motility in abduction and/or elevation was seen in 20 (54%) individuals before decompression and in 23 (62%) after. Strabismus surgery was performed in 22 patients. On final examination 85% of the study population were totally free of diplopia or experienced diplopia only in the peripheral field of gaze. Three patients developed sinusitis. Of these, endoscopic sinus surgery was performed in two patients, and one patient was conservatively treated. Symptoms resolved in all three patients.

Endoscopic medial orbital decompression including removal of the medial floor of the orbit is a safe and effective procedure for treatment of thyroid eye disease. Navigation can be of valuable help to ensure complete resection of the bony walls. However, the majority of patients will need subsequent strabismus surgery, mainly due to significant increase of esotropia.