Thymectomy In The Treatment Of Ocular Myasthenia Gravis And Relevant Influencing Factors

Objective:To evaluate the efficacy of thymectomy, access the relevant influencing factors for the treatment of ocular myasthenia gravis.Methods:We conduct a review and follow-up of all 63 patients who had diagnosed OMG and received treatment between January 2003 and December 2009 at the neurology department of The First Affiliated Hospital of Fujian Medical University. Patients'response to treatment was categorized as follows: Effective or ineffective, convert to generalized myasthenia gravis or remain purely ocular weakness. The rate of efficiency between thymectomy group and non-surgical treatment group was compared by Chi-square test and the rate of conversion between two groups was compared by Kaplan-Meier analysis. An analysis was studied in comparison of thymectomy, age, gender, oral prednisone, chest CT; accompany autoimmune diseases and oral immunosuppressive drugs with Cox regression analysis model.Results:26 cases had received thymectomy, 2 cases lost; non-surgical treatment of 37 patients, 4 cases lost. 57 casfes were followed up for a median duration of 36 months(range 2-360months,interquartile range 99 months). Histological thymic abnormalities were found in 88.5% of the thymectomy group. The rate of conversion was lower in the thymectomy group than non-surgical group (Log-Rank, P<0.05), and the effective rate was higher in the thymectomy group(Chi-square, P<0.05). After we exclude thymoma patients by chest CT for analysis, the rate of conversion was lower in the thymectomy group than non-surgical group (Log-Rank, P<0.05), and the effective rate was no difference between two groups(Chi-square,P>0.05). The COX regression model reveals that the rate of conversion was statistically independent of thymectomy and chest CT.Conclusion:Histological thymic abnormalities were common in OMG. Thymectomy is a safe treatment for OMG, it can prevent the progression of OMG to GMG, but it dose not significantly improve the symptoms or increase the cure rate in nonthymomas.