VARIABLES AFFECTING THE LONG TERM OUTCOME OF GRAVES' ORBITOPATHY FOLLOWING HIGH DOSE INTRAVENOUS GLUCOCORTICOID PULSE THERAPY IN PATIENTS NOT TREATED WITH ORBITAL RADIOTHERAPY

OBJECTIVE: Intravenous (iv) glucocorticoids (GC) (ivGC) are used for active Graves orbitopathy (GO), but factors affecting GO outcome are poorly understood. We performed a retrospective study to investigate the variables affecting GO after ivGC. METHODS: We evaluated 83 consecutive GO patients treated with ivGC but not orbital radiotherapy (ORT) and re-examined them after a median of 47 months. The endpoints were the relationships between GO outcome or additional treatments with age, sex, smoking habits, thyroid volume, thyroid treatment, time since thyroid treatment, antithyroid-stimulating hormone receptor antibodies (TRAb), GO duration, GO features, and follow-up time. RESULTS: GO features improved after treatment, resulting in moderate and marked amelioration in ~75% and ~41% of patients respectively. By multivariate analysis, a moderate GO improvement correlated with diplopia at first observation, which was more severe in responders. A marked GO improvement correlated with time between first and last observation and time after thyroid treatment, which were longer in responders. This likely reflected the combination of an early effect of GC and a late, spontaneous improvement of GO, as shown by analyses of GO outcome at various time points. Additional treatments after ivGC correlated by multivariate analysis with eyelid aperture, diplopia and NOSPECS score (NOSPECS stands for no GO signs [N], only eyelid sign [O], soft tissue involvement [S], proptosis [P], extraocular motility restriction [E], corneal involvement [C], and sight loss [S]) at first observation, which were more severe in responders. CONCLUSION: Our study shows that response to ivGC increases with time, likely reflecting the known tendency of GO to improve spontaneously, and is more pronounced when GO is more severe to begin with, which is associated with more additional treatments. ABBREVIATIONS: ANOVA = analysis of variance CAS = clinical activity score GC = glucocorticoids GO = Graves orbitopathy 131I = radioactive iodine iv = intravenous ivGC = high-dose intravenous glucocorticoid pulse therapy MMI = methimazole OD = orbital decompression ORT = orbital radiotherapy TRAb = antithyroid-stimulating hormone receptor antibodies.