[Indication of thymectomy and immunotherapies on myasthenia gravis].

First, we studied clinical effects of thymectomy on non-thymomatous ocular myasthenia gravis (MG) patients by comparing operative and non-operative groups. The QMG scores reduced with similar significances in both groups. Thymectomy is considered to be unnecessary in non-thymomatous ocular MG. Second, we discussed over the issue how elderly-onset MG patients could be treated. We believe that thymectomy is sufficiently tolerable and therefore could be selected with low dose oral prednisolone in moderate to severe MG cases. However we should be aware of various complications which are common in elderly patients. In mild cases, we can treat with anti-cholinesterase only. Third, we compared the long term effect of endoscopic thymectomy (infrasternal mediastinoscopic thymectomy) with conventional transsternal method. QMG scores and anti-AChR antibody titers reduced in both groups with similar significances suggesting that endoscopic thymectomy is as effective as transsternal thymectomy in treating MG.