LONG-TERM VISUAL OUTCOME FOLLOWING ORBITAL DECOMPRESSION FOR DYSTHYROID EYE DISEASE

The records of 33 patients who had undergone inferior and medial wall orbital decompressions for compressive optic neuropathy due to dysthyr oid eye disease were reviewed. The indication for surgery in 32 patien ts was a reduction in Snellen visual acuity, The remaining patient had bilateral optic disc swelling but normal visual acuity. Twenty-nine p atients (88%) were treated with systemic steroids pre-operatively, whi ch resulted in an improvement in vision in all cases. In the immediate post-operative period visual acuity either improved or the steroid-in duced visual improvement was maintained as the steroids were tailed of f. Long-term visual outcome, however, varied. In 19 patients (58%) vis ual acuity was maintained,vith no requirement for additional treatment . In 12 patients (36%) there was a subsequent deterioration in vision which responded to additional treatment with either systemic steroids, orbital radiotherapy or further orbital surgery. In 2 patients (6%) v ision continued to deteriorate despite further treatment. We conclude that although orbital decompression has resulted in the long-term pres ervation of visual acuity in 94% of our patients, there remains a smal l subgroup (6%) in whom visual function continues to deteriorate despi te all forms of treatment.