Sir,

We are grateful to Drs Litwin and Malhotra1 for their interest in our paper,2 and for outlining a useful adjunctive therapy for upper eyelid retraction during the acute phase of thyroid eye disease. We note with interest that double the normal dose of BoNTA is required, this suggesting an attenuated effect likely to be due to hypervascularity of the inflamed tissues. This higher dose confers a risk of reduced superior rectus action and Bell’s response, with the studies by Morgenstern et al3 (transconjunctival route, active disease), and Shih et al4 (transcutaneous route, inactive disease) both noting increased diplopia in a small number of patients. It is this risk—and consequently that of corneal exposure in patients whose ocular elevation may already be compromised—that is of concern, but the authors (RM and AL) are to be congratulated for not having had this complication to date in their own series, and we are grateful for their insights on the management of these patients.