EFFECTS OF BILATERAL ORBITAL DECOMPRESSION BY AN ENDOSCOPIC ENDONASALAPPROACH IN DYSTHYROID ORBITOPATHY

Aims - The efficacy of endoscopic endonasal orbital decompression in d ysthyroid orbitopathy was analysed. Methods - In 21 consecutive cases of bilateral operation short term (10 (SD 6) days after operation) and long term (156 (12) days after operation) results were recorded. Resu lts - Short term results showed that vision of the more affected eye i mproved from a mean of 0.35 to 0.59; vision improved in all but one ey e which remained unchanged. In the fellow eyes mean visual acuity impr oved from 0.6 to 0.7; three of these eyes showed a decrease. Mean prop tosis returned from 23.0 mm to 20.0 mm. As to motility the mean abduct ive capacity decreased from 5.5 mm to 4.0 mm of monocular excursion, w hereas adduction increased from 7.5 mm to 8.5 mm. Upgaze and downgaze did not show any major change. The mean angle of horizontal squint shi fted from 7.5 degrees of convergence to 15.5 degrees while no signific ant vertical or cyclorotational deviation was induced. These immediate postoperative results proved to be stable for the period of long term follow up with only slight changes. No significant bleeding or specif ic otorhinolaryngological complication without resolve occurred intrao peratively or perioperatively. Conclusion - This method is believed to be superior to non-endoscopic techniques because it avoids external s cars and antral pain. With regard to the relief of intraorbital pressu re, the technique gives good results for visual acuity improvement, bu t in proptosis reduction the method is not as efficient as external or combined procedures. There seems to be no difference when compared wi th other approaches in induction of horizontal squint. The method has a protective long term effect against the recurrence of compressive op tic neuropathy.