Statistical Analysis Differences in the prevalence of smokers in the two studies were analyzed by using a chi-square test with Yates correction for continuity. Neither funding source had a role in the collection, analysis, or interpretation of the data or in the decision to submit the paper for publication. Duration of ophthalmopathy did not differ among groups. In addition, smoking was associated with reduced efficacy of glucocorticoids given concomitantly with radioiodine. In the retrospective study, smoking and degree of smoking seemed to adversely affect the outcome of orbital radiation therapy and high-dose glucocorticoid treatment in patients with severe ophthalmopathy.
Cigarette smoking is a risk factor for Graves ophthalmopathy.
The differences between our results and those of previous studies may be explained by the larger number of patients and the consequent greater power of our study. Our results suggest that smoking also negatively affects treatment outcome. Of note, several smokers in study 1 had no progression of ophthalmopathy after radioiodine therapy, and the condition improved with concomitant prednisone treatment. Similarly, in study 2, several smokers had excellent or good responses to orbital radiation therapy and high-dose glucocorticoid therapy. This implies that cigarette smoking is only one of many risk factors involved in the progression of ophthalmopathy.