Management of lid retraction-Bridge Mullerectomy

A 46-year-old male with inactive thyroid eye disease was referred to oculoplasty department for prominent eyes. Examination revealed bilateral upper lid retraction of 3 mm, lagophthalmos with minimal corneal exposure changes with no proptosis [Figure 1a]. The best corrected visual acuity was 6/6 in both eyes.Figure 1: (a) Intra operative pic of modified Muller ectomy showing the medial and lateral pillars of Mullers muscle leaving the central pillar intact. (b) pre-op and (c) post op photographThyroid eye disease [TED] is a complex autoimmune inflammatory disorder of the orbit. Approximately, 20% to 50% of Graves’ disease is present with TED.[1] Thyroid orbitopathy often presents with eyelid retraction, proptosis and lagophthalmos-induced exposure keratopathy, which can result in visual impairment and social awkwardness because of cosmetic disfigurement. Rundle’s curve explains the natural course of the disease as an initial inflammatory phase followed by a plateau quiescent phase and a final phase of remission. Surgical intervention is generally indicated during the quiescent stage in a stepwise approach.[2] Proptosis correction using orbital or fat decompression first, followed by strabismus correction and residual eyelid retraction repairs at the end. However, several studies have proven a single-stage procedure has similar success rates as a staged procedure.[3] Lid retraction correction depends on the extent of severity. Studies suggest that for a retraction of 3mm or less, a posterior approach Muller’s muscle resection and in cases with more than 3mm of retraction, full thickness blepharotomy is recommended.[4] Numerous other surgical techniques have been described, aiming to obtain predictable and satisfactory postoperative eyelid contour and height, including Muller’s muscle recession or excision, anterior or posterior levator recession with or without adjustable sutures, upper lid spacer grafts, levator lengthening orbital septal flap, and medial transposition of the lateral horn of the levator aponeurosis.[4] Approach Müller’s muscle resection or recession avoids an external upper eyelid scar and leaves the anterior eyelid structures intact, thus facilitating a revision by an anterior approach if needed.[4] In 1965, Henderson introduced the concept of a graded approach using a conjunctival incision. In 1981, Harvey and Anderson advocated the anterior approach with levator recession and complete extirpation of Muller’s muscle. Several authors have modified these two techniques, all reporting good results.[5] In this essay, a modified Hendersons technique that leaves a central pillar of Mullers during surgery was used [Figure 1b]. Surgical technique: The retracted upper eyelid is everted, and anaesthetic agent is infiltrated subconjunctivally along the supratarsal border. A 4–0 silk retraction suture is passed through the central eyelid margin at the grey line, and the upper eyelid is then everted over a Desmarres retractor. The conjunctiva is grasped at the superior tarsal border and incised. A sharp pointed scissor is inserted between the conjunctiva and Mullers muscle and a pocket is created by spreading the scissor blades. The conjunctiva is then detached from the upper tarsal border toward the superior fornix. The lateral third of Muller’s muscle is then grasped and separated from the underlying levator and severed up to 10–15 mm above the superior tarsal border. Likewise medial third is also separated and excised, leaving behind a central pillar of Muller’s muscle intact. Releasing Mullers muscle nasally can be conservative to avoid nasal droop.[6] The patient can be made to sit upright and assessed for the lid height If still retracted the levator aponeurosis can be stripped vertically and lengthened. This can be done gradually and accurately.[7] This procedure is less invasive than the anterior approach. Mullers is better identified from the posterior aspect. The procedure is conducted with very minimal sensory anaesthesia and not motor unlike, the anterior approach. Hence, graded resection of Muller’s muscle can be conducted with height adjustment on the table by making the patient sit upright. Post-operative retraction is minimal and it can be considered an ideal procedure for mild to moderate ptosis. The difficulty arises in the separation of Muller’s muscle which should be done meticulously and carefully as it is adherent to the conjunctiva firmly. When a combined procedure such as a blepharoplasty is needed, this procedure may not be ideal. This technique is not suitable for severe lid retraction or in conditions where the anterior lamellae are deficient. Bridge Muller ectomy allows adequate lowering of the eyelid but maintains the curved contour. Alternatively, central eyelid flattening that can develop after complete Muller ectomy or blepharotomy is avoided. The upper lid should be positioned at mid-pupillary level in the immediate post-operative period, at the end of 1 month the lid usually raises by a millimeter or two and remains stable at 3 months [Figure 1c]. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.