Comment on “A Modified Levator Resection Technique Involving Retention of the Levator Palpebrae Superioris Muscle Suspension System for Treatment of Congenital Ptosis”

We read with great interest the article entitled ‘‘A modified levator resection technique involving retention of the levator palpebrae superioris muscle suspension system for treatment of congenital ptosis’’ by Zuo et al. [1]. The authors clearly highlight the importance of protecting as much as possible the integrity of the eyelid structure to prevent instability and postoperative discomfort for patients. We appreciate the effort to preserve the anatomy of the Whitnall ligament and of the medial and lateral horns, conserving the suspensory system of the levator palpebrae superior muscle (LPS), and we congratulate the authors for the large series of cases and for the excellent results. We fully agree that LPS is the most important muscle for elevating the upper eyelid. Its management is the ideal method for correcting congenital ptosis, but its function, excluding the frontalis muscle contribution, should be considered with the degree of the ptosis in preoperative planning. Furthermore, preoperative asymmetry represents one of the most popular risk factors for reoperation and it must be carefully investigated preoperatively. The compensatory retraction of the minor affected eye makes it difficult to adjust the balance between the two eyes. Compensation for the superior visual field loss by the recruitment of the frontalis muscle should be also assessed considering, at the same time, the degree of levator functional excursion. Recently, we published an article to evaluate long-term-follow-up results after blepharoptosis correction with external levator advancement, considering both functional and esthetic results [2]. The former can be evaluated based on post-op upper lid margin reflex distance (uMRD) measurement, while the symmetry represents one of the most important esthetic goals [3]. According to The British Oculoplastic Surgery Society National Ptosis Survey, a successful outcome can be considered when uMRD was between 3 and 5 mm. Symmetry was achieved when all the following 3 different criteria were met [4]