I have been using Botox for treating the glabella for well over two decades. During that time I have on occasion encountered individuals, such as it sounds like here, in which asymmetry of the heights between the medial eyebrows is so pronounced as to present a significant aesthetic problem. I have found that treating the more depressed side with Botox (in order to weaken the downwardly pulling, depressor muscles responsible for this) can lead to sufficient elevation as to improve this and restore better symmetry. Since this is not a "cookbook" case of simply treating ordinary "eleven lines," be sure to seek consultation with a board certified aesthetic physician with extensive experience in the advanced cosmetic uses of neuromodulators. Best of luck.