Pathogenesis and surgical correction of dynamic lower scleral show as a sign of disinsertion of the levator aponeurosis from the tarsus *

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1 British Journal of Plastic Surgery (2005) 58, Pathogenesis and surgical correction of dynamic lower scleral show as a sign of disinsertion of the levator aponeurosis from the tarsus * Kiyoshi Matsuo*, Shoji Kondoh, Takeshi Kitazawa, Yoshimasa Ishigaki, Niroh Kikuchi Department of Plastic and Reconstructive Surgery and, Shinshu University School of Medicine, Matsumoto, Nagano , Japan Received 2 June 2004; accepted 23 December 2004 KEYWORDS Lower scleral show; Upward displacement of the globe; Retraction of the lower eyelid; Disinsertion of the levator aponeurosis from the tarsus; Capsulopalpebral fascia; Inferior suspensory ligament of Lockwood Summary The purpose of this study was to confirm whether lower scleral show is caused by the disinsertion of the levator aponeurosis from the tarsus. Aponeurotic advancement by vascular clips or by surgery involving the orbital septum significantly lowered the global position in the orbit and significantly diminished the degree of retraction of the lower eyelid, resulting in satisfactory improvement of lower scleral show in 100 patients with various aponeurotic blepharoptosis. Therefore, we propose the pathogenesis of lower scleral show as follows: additional contraction of the levator muscle to compensate for the disinsertion of the levator aponeurosis from the tarsus for maintenance of an adequate visual field is accompanied by additional contraction of the superior rectus muscle through the strong intermuscular fascia, resulting in upward rotation of the globe. To maintain the horizontal visual axis and foveation without inclination of the head in the primary gaze position, additional contraction of the inferior rectus muscle is induced, which pulls upon the inferior suspensory ligament of Lockwood and the capsulopalpebral fascia. The former displaces the globe upwards and the latter retracts the lower eyelid, resulting in dynamic lower scleral show as a sign of disinsertion of the levator aponeurosis from the tarsus, which can be surgically corrected. q 2005 The British Association of Plastic Surgeons. Published by Elsevier Ltd. All rights reserved. * Presented in part at the 43rd Annual Meetings of the Japan Society of Plastic and Reconstructive Surgery, Sapporo, Japan, October 25, 2000 and in part at the 46th Annual Meeting of the Japan Society of Plastic and Reconstructive Surgery, Kobe, Japan, April 9, * Corresponding author. Tel.: C ; fax.: C address: kmatsuo@hsp.md.shinshu-u.ac.jp (K. Matsuo). We have reported that disinsertion of the levator aponeurosis from the tarsus in growing children causes the upward displacement of the superior palpebral crease and the upward displacement of the globe in the orbit, the latter of which shows lower sclera without inclination of the head (Fig. 1(B)). 1,2 The upward displacement of the superior palpebral crease is thought to be caused by S /$ - see front matter q 2005 The British Association of Plastic Surgeons. Published by Elsevier Ltd. All rights reserved. doi: /j.bjps

2 Dynamic lower scleral show 669 Figure 1 Hypothetical schematic diagrams of the relationships among the levator (LM), superior rectus (SR), and inferior rectus (IR) muscles, the capsulopalpebral fascia (CP), the inferior suspensory ligament of Lockwood (L), the lower eyelid, and the globe. (A) Normal eyelid without disinsertion of the levator aponeurosis from the tarsus. OS, orbital septum; LA, levator aponeurosis; ITL, inferior transverse ligament W: Whitnall s ligament; MM, Müller s muscle. (B) After the aponeurosis is disinserted from the tarsus, additional contraction of the inferior rectus muscle accompanied with the levator and superior rectus muscles displaces the superior palpebral crease (SPC) upwards and the lower eyelid downwards and the globe upwards by means of traction of the capsulopalpebral fascia and the inferior suspensory ligament of Lockwood, resulting in lower scleral show. (C, D) Advancement of the orbital septum, which is the superficial expansion of the levator aponeurosis, by vascular clips or surgery relaxes the superior and inferior rectus muscles, lessens the traction of the capsulopalpebral fascia and the inferior suspensory ligament of Lockwood, raises the lower eyelid, and lowers the globe in the orbit. additional traction of the pretarsal skin and orbicularis oculi muscle between the superior palpebral crease and the lid margin as the result of additional contraction of the levator muscle to maintain an adequate visual field. 3 We hypothesised that lower scleral show is caused by the compensatory strategies for the disinsertion of the levator aponeurosis from the tarsus as follows: 1 additional contraction of the levator muscle is induced to compensate for the disinsertion of the levator aponeurosis from the tarsus for maintenance of an adequate visual field. Because the levator and superior rectus muscles embryologically arise from the same origin, are innervated by the same superior branch of the oculomotor nerve, and are connected with a strong intermuscular fascia, 4 7 the globe may be rotated upwards by traction of the superior rectus muscle accompanied by the additional contraction of the levator muscle. To maintain the horizontal visual axis and foveation without inclination of the head in the primary gaze position, additional contraction of the inferior rectus muscle is induced, which pulls upon the inferior suspensory ligament of Lockwood. This

3 670 ligament anteroinferiorly supports the globe and connects with the inferior rectus muscle, thus resulting in the upward displacement of the globe in the orbit. On the basis of this hypothetical pathogenesis of dynamic lower scleral show as the result of additional contraction of the inferior rectus muscle, there is a strong possibility that aponeurotic advancement using the orbital septum can correct lower scleral show (Fig. 1(D)). 8 The purpose of this study was to confirm whether dynamic lower scleral show is caused by disinsertion of the aponeurosis from the tarsus and can be surgically corrected by aponeurotic advancement in patients with various aponeurotic blepharoptosis. 9 Patients and method One hundred consecutive patients with various degrees and stages 9 of aponeurotic blepharoptosis (82 women and 18 men, median age 39.4G23.1 years), who had unilateral or bilateral lower scleral show in the primary gaze position, were examined pre-operatively, intraoperatively, and post-operatively (Figs. 2 5). Pre-operatively, the global position was photographed in the primary gaze position without inclination of the head (Figs. 2(A), 3(B), 4 left column, and 5(A) and (C)). After the orbital septum, which corresponds to the superficial expansion of the levator aponeurosis, 10 was temporarily advanced and fixed with the upper part of the eyelid skin with using vascular clips (60 g for vein, Bear, Tokyo, Japan), the global position was photographed (Figs. 1(C), 2(B), 3(B) and 4 central column). Clipping may induce intolerable pain, so 60% lidocaine tape should be applied before this procedure. Intraoperatively, after the disinserted levator aponeurosis was confirmed by the presence of slippage from the tarsus (Fig. 2(C)) 9 and was advanced and fixed onto the tarsus using the orbital septum (Figs. 1(D), 2(D), and 3(C)), 8 the global position was photographed to confirm whether unilateral aponeurotic advancement might cause unilateral downward displacement of the ipsilateral globe (Fig. 2(D)). Post-operatively, the global position was photographed in the same head position as the pre-operative one (Figs. 2(F), 4 right column, and 5(A) and (C)). The head position was assessed from the shape of the nostrils and palpebral fissures and from the vertical relationships between the blepharal, nasal, oral, and auricular positions (Fig. 5(A) and (C)). To evaluate the global position in the orbit, distances from the centre of the cornea to the line between the bilateral medial canthi were measured and the pre-operative and post-operative data were statistically compared (Figs. 2(A) and (F), 4 left and right columns, and 5(A)). When the global position was lowered more than 1 mm by pre-operative temporary aponeurotic advancement with vascular clips (Figs. 2(A) and (B), 3(A) and (B), and 4 left and central columns) or surgical unilateral aponeurotic advancement (Fig. 3(A), (C) and (D)), it was judged as apparent lowering. To evaluate changes in the degree of retraction of the lower eyelid, the areas enclosed the lower lid margin and the line between the medial and lateral canthi were measured and the pre-operative and post-operative data were statistically compared (Figs. 2(A) and (F), 4 left and right columns, and 5(C)). In patients with bilateral lower scleral show, the ipsilateral globe and eyelid, which was evaluated by means of the pre-operative temporary aponeurotic advancement by vascular clips and the surgical unilateral aponeurotic advancement, was evaluated as well. All measurements were based on photographs with a 10-mm square scale (Casmatch, Dai Nippon Printing Co., Ltd., Tokyo, Japan) (Figs. 2 5). Statistical analysis was performed with a StatView system (Version 5.0, Abacus Concept, Berkeley, CA) using the Wilcoxon signed-ranks test. A p value of!0.05 was considered to indicate a significant difference. Written informed consent for photographic analysis was obtained from all patients. Results K. Matsuo et al. Pre-operative temporary aponeurotic advancement by vascular clips resulted in the apparent lowering of the globe in 91 of the 100 patients (Figs. 2(A) and (B), 3(A) and (B), and 4 left and central columns). Drooping of the contralateral eyelid (Hering s law) was observed in 58 of the 91 patients (Figs. 2(B), 3(B) and 4(A) and (E) (G)). Unilateral aponeurotic advancement resulted in the apparent lowering of the ipsilateral globe in 61 of the 100 patients (Figs. 2(A)and(E) and 3(A) and (D)). The post-operative distance from the centre of the cornea to the intercanthal line was significantly lower than the pre-operative one (p!0.0001) (Fig. 5(B)). The post-operative area enclosed by the lower lid margin and the line between the medial and lateral canthi was significantly lower than the pre-operative one (p!0.0001) (Fig. 5(D)).

4 Dynamic lower scleral show 671 Figure 2 A 32-year-old male patient with unilateral lower scleral show. (A, B) Temporary aponeurotic advancement by vascular clips is performed to confirm whether aponeurotic surgery will correct the global position and cause the diplopia. (C) Intraoperatively, how the disinserted levator aponeurosis slips from the tarsus is determined. The stretching of Mueller s muscle induces involuntary contraction of the bilateral levator muscles. 12 (D) Aponeurotic advancement and fixation with three stitches is unilaterally performed in the right eyelid. (E, F) The right global position in the orbit is lowered immediately after the fixation and 4 months after surgery. Discussion Aponeurotic advancement by vascular clips or surgery significantly lowered the global position in the orbit and significantly diminished the degree of retraction of the lower eyelid, resulting in satisfactory improvement of lower scleral show. These findings not only verified the presence of dynamic lower scleral show by additional contraction of the inferior rectus muscle but also validated our hypothetical pathogenesis of the upward displacement of the globe in the orbit. 1 When the aponeurosis is advanced, not only the levator muscle but also the superior rectus muscle is advanced through the strong intermuscular fascia, resulting in downward rotation of the globe. To maintain the horizontal axis and foveation, the inferior rectus muscle must be relaxed, resulting in less traction of the inferior suspensory ligament of Lockwood and the capsulopalpebral fascia (Fig. 1(C) and (D)). We have reported that aponeurotic blepharoptosis can be classified into decompensated and compensated stages, which depends on the degree of disinsertion and attenuation of the aponeurosis. 9 In the decompensated stage, even excessive contraction of the levator muscle to maintain an adequate visual field can no longer compensate for a large slippage between the levator aponeurosis and the tarsus, resulting in the clinical manifestation of blepharoptosis in the primary gaze position. Additional contraction of the inferior rectus muscle accompanied with the levator and superior rectus muscles causes lower scleral show (Fig. 4(A) (D)). In the compensated stage, additional contraction of the levator muscle accompanied with the superior and inferior rectus muscles to maintain an adequate visual field can

5 672 K. Matsuo et al. Figure 3 A 30-year-old female patient with bilateral lower sclera show. (A, B) The vertical global position from the center of the cornea to the intercanthal line is measured pre-operatively without or with temporary aponeurotic advancement by vascular clips. The blue line indicates the horizontal position of the lower corneal limbus. (C) Aponeurotic advancement and fixation with three stitches (arrow) is unilaterally performed in the right eyelid. (D) The global position is measured to confirm whether unilateral aponeurotic advancement might cause unilateral downward displacement of the ipsilateral globe. The blue line on the lower corneal limbus helps to measure the global position in ptotic eyelid according to Hering s law. compensate for the slippage, resulting in lower scleral show without the clinical manifestation of the blepharoptosis. We have also reported that the superficial expansion of the levator aponeurosis turned up around the inferior transverse ligament to become the orbital septum and that this ligament determines the low position of the preaponeurotic fat and restricts the vertical width of the palpebral fissure, causing the features of Mongoloid eye. 10 When patients with the compensated aponeurotic blepharoptosis have a strong inferior transverse ligament, retraction of the upper eyelid may be restricted, resulting in the narrow vertical palpebral fissure (Fig. 4(E) and (F)). When they do not have a strong ligament, retraction may be not restricted, resulting in the wide vertical palpebral fissure (the goggled eyes) (Fig. 4(G) and (H)). In our study, patients with various degrees and stages of aponeurotic blepharoptosis who had lower scleral show in the primary gaze position were analysed. However, there are patients with aponeurotic blepharoptosis who do not have lower scleral show. We previously reported the possibility that patients whose inferior suspensory ligament of Lockwood may be well developed or whose Whitnall s transverse ligament may not be well developed may exhibit scleral show (Fig. 1(B)). 1 However, further study to confirm a mutual relationship between the inferior suspensory ligament of Lockwood and Whitnall s transverse ligament will be needed. Because the levator, superior rectus, and inferior rectus muscles are thought to function as yoke muscles, unilateral advancement of the aponeurosis by clips and surgery causes Hering s law (Figs. 2(B), 3(B) and 4(A) and (E) (G)). However, the presence of the unilateral lower scleral show cannot be explained by the function of the yoke muscles (Figs. 2 and 4(A) and (B)). After surgical correction of the unilaterally disinserted aponeurosis, the asymmetrical condition was almost corrected (Figs. 2 and 4(A) and (B)). Therefore, another route for the unilateral muscles to function may exist, one which might be induced by the presence of the unilaterally disinserted aponeurosis. The asymmetrical global position, seen as the unilateral upward displacement of the globe in the orbit, should be differentiated from strabismus, seen as the rotational abnormality of the globe. Double vision in the upward displacement of the globe did not exist pre-operatively, intraoperatively, or post-operatively in our patients even when temporary aponeurotic advancement by vascular clips or surgical aponeurotic advancement was unilaterally performed. Lower scleral show can be classified as static and dynamic. Static lower scleral show may be

6 Dynamic lower scleral show 673 Figure 4 Changes of lower scleral show in eight patients. In the left column are pre-operative photos. In the central column are pre-operative photos with temporary aponeurotic advancement by vascular clips. In the right column are post-operative photos of the primary gaze position. The vertical level and size of the photos of each patient in the left, central, and right columns were adjusted based on the intercanthal line and the square scale. (A, B) Unilateral lower scleral show in patients with unilateral decompensated aponeurotic blepharoptosis. (C, D) Bilateral lower scleral show in patients with bilateral decompensated aponeurotic blepharoptosis. (E, F) Bilateral scleral show in patients with bilateral compensated aponeurotic blepharoptosis and the features of Mongoloid eye. (G, H) Bilateral scleral show in patients with bilateral compensated aponeurotic blepharoptosis (the goggled eye). recognised as lower eyelid laxity or post-blepharoplasty eyelid malposition. It may be differentially diagnosed by temporary aponeurotic advancement with vascular clips. Before surgical intervention to the lower eyelid, aponeurotic surgery should be considered as another resolving method. To assess the upper eyelid levels in blepharoptosis, the distance from a corneal light reflex to the central upper eyelid margin (margin reflex distance, MRD) is used. 11 Because the globe in the orbit can moves vertically accordingly to the degree of contraction of the inferior rectus muscle, the distance from the

7 674 K. Matsuo et al. Figure 5 Statistical analysis of the global position in the orbit and the degree of retraction of the lower eyelid. (A, B) Changes in pre-operative and post-operative distances form the center of the cornea to the line between the medial canthi. (C, D) Changes in pre-operative and post-operative areas enclosed by the lower lid margin and the line between the medial and lateral canthi. intercanthal line to the centre upper eyelid margin may be more constant than MRD. In conclusion, dynamic lower scleral show without inclination of the head may indicate additional contraction of the inferior rectus muscle accompanied with the levator and superior rectus muscles, which implies the presence of disinsertion of the levator aponeurosis from the tarsus, which can be surgically corrected. References 1. Sultana R, Matsuo K, Yuzuriha S, Kushima H. Disinsertion of the levator aponeurosis from the tarsus in growing children. Plast Reconstr Surg 2000;106: Mackinnon SE, Fielding JC, Dellon AL, Fisher DM. The incidence and degree of scleral show in the normal population. Plast Reconstr Surg 1987;80: Jelks GW, Smith BC. In: McCarthy JG, editor. In: Reconstruction of the eyelids and associated structures, vol. 2. Philadelphia, PA, USA: W.B. Saunders; Sevel D. The origins and insertions of the extraocular muscles: development, histologic features, and clinical significance. Trans Am Ophthalmol Soc 1986;84: Stasior GO, Lemke BN, Wallow IH, Dortzbach RK. Levator aponeurosis elastic fiber network. Ophthal Plast Reconstr Surg 1993;9: Lemke BN, Stasior OG, Rosenberg PN. The surgical relations of the levator palpebrae superioris muscle. Ophthal Plast Reconstr Surg 1988;4: Ettl A, Priglinger S, Kramer J, May PJ. Functional anatomy of the levator palpebrae superioris muscle and its connective tissue system. Br J Ophthalmol 1996;80: Matsuo K. Restoration of involuntary tonic contraction of the levator muscle in patients with aponeurotic blepharoptosis or Horner syndrome by aponeurotic advancement using the orbital septum. Scand J Plast Reconstr Surg Hand Surg 2003; 37: Fujiwara T, Matsuo K, Kondoh S, Yuzuriha S. Etiology and

8 Dynamic lower scleral show 675 pathogenesis of aponeurotic blepharoptosis. Ann Plast Surg 2001;46: Yuzuriha S, Matsuo K, Kushima H. An anatomical structure which results in puffiness of the upper eyelid and a narrow palpebral fissure in the Mongoloid eye. Br J Plast Surg 2000; 53: Putterman AM, Fett DR. Müller s muscle in the treatment of upper eyelid ptosis: a ten-year study. Ophthalmic Surg 1986; 17: Matsuo K. Stretching of the Mueller muscle results in involuntary contraction of the levator muscle. Ophthal Plast Reconstr Surg 2002;18:5 10.