The role of surface electromyography in confirming the effect of blepharoplasty on strength of levator palpebrae superioris muscle in congenital blepharoptosis

Abstract

Background Blepharoptosis is an abnormal drooping of the upper eyelid margin with the eye in the primary gaze position. The clinical evaluating tests of upper eyelid muscle function lack objectivity, while surface electromyography (SEMG) is an objective evaluating tool of muscle power. We aimed to confirm the effect of blepharoplasty on levator muscle power after its shortening via levator aponeurosis resection surgery in cases of congenital ptosis through electrophysiological and clinical studies. The study included 40 patients aged ≥ 10 years with congenital blepharoptosis from the ophthalmology department of our university hospital, along with 40 age- and sex-matched healthy controls. All participants were subjected to clinical and electrophysiological assessment of levator muscle before and after blepharoplasty. Results There was a significant improvement in clinical and electrophysiological findings among cases post-surgery compared with preoperative parameters. We recorded clinical improvement in 90% of patients postoperatively regarding eyelid morphology, symmetry, and visual field. Meanwhile, 82.5% of patients showed improvement in their muscle power using SEMG parameters in terms of improved muscle amplitude and firing characters compared with preoperative measures. Conclusion SEMG provides a standardized, objective method of analysis of upper eyelid muscle power. It confirms that levator muscle shortening via levator aponeurosis resection surgery could increase its power based on its pre-surgical power and electrophysiological characteristics; so, it could be considered an indicator of post-operative improvement of ptosis based on electrophysiological measurements before surgery. The relatively short follow-up period and lack of quantitative analysis of EMG were limitations of this study.