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Orbital Septum Attachment on the Levator Aponeurosis in Asians
Orbital Septum Attachment on the Levator Aponeurosis in Asians In Vivo and Cadaver Study Hirohiko Kakizaki, MD, PhD,1 Igal Leibovitch, MD,2 Dinesh Selva, FRACS, FRANZCO,3 Ken Asamoto, MD, PhD,4 Takashi Nakano, MD, PhD4 Purpose: To examine the anatomic relationships between the preaponeurotic fat pad, orbital septum, and the distal end of the anterior layer of the levator aponeurosis (DEALLA) in relation to the superior tarsal plate border. Design: Prospective, clinical case series and experimental anatomic study. Participants: Twenty-two upper eyelids in 11 Asian patients (average age, 76.5 years) and 10 postmortem upper eyelid specimens of 7 Asians (average age, 81 years). Methods: The relationships between the orbital septum, DEALLA, preaponeurotic fat pad, and the superior tarsal plate border were examined in vivo, during upper blepharoplasty. In cadavers, the orbital septum was exposed and excised from the DEALLA, and the distance from the superior tarsal plate border to the DEALLA was measured at 3 points: the center of the palpebral width, and 2 points located 7 mm medial and lateral to the center. Main Outcome Measures: The anatomic relationships of the orbital septum, DEALLA, and the preaponeurotic fat pad with the superior tarsal plate border. Results: In vivo, the DEALLA was always located above the superior tarsal plate border, and the lower margin of the preaponeurotic fat was always positioned below the DEALLA and around the superior tarsal plate border. The lateral preaponeurotic fat in 4 eyelids showed extension beyond the superior tarsal border. In cadavers, the average distance from the superior tarsal plate border to the DEALLA was 3.7 mm centrally, 3.0 mm medially, and 0.9 mm laterally. In 3 specimens, the confluent part of the orbital septum and the levator aponeurosis reached the tarsus in the lateral area. Conclusions: Orbital septum attachment on the levator aponeurosis in Asians seems to be situated above the superior tarsal plate border in vivo, but the preaponeurotic fat extends beyond the DEALLA, sometimes reaching the tarsal plate. In some cadavers, the confluent part was found to be situated on the tarsus laterally. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. Ophthalmology 2009;116:2031–2035 © 2009 by the American Academy of Ophthalmology.
The attachment of the orbital septum to the levator aponeurosis in Asians is thought to be lower than that in white persons, usually extending to the tarsal plate.1–3 This may explain an inferior extension of the preaponeurotic fat pad in Asians, which together with a thicker suborbicularis tissue creates a prominent upper eyelid fold and a fullerappearing eyelid.1– 4 It also has been postulated that the inferior extension of the orbital septum may block the superficial fibers of the anterior levator aponeurosis that normally form the eyelid crease, thereby creating a lower or a less distinctly formed eyelid crease.1 Microscopic anatomic studies in Asian upper eyelids have shown recently, however, that the confluent part of the orbital septum on the levator aponeurosis is located above the superior border of the tarsal plate.5 Because the orbital septum has a certain thickness and a layered structure,6 the distal end of the anterior layer of the levator aponeurosis (DEALLA) was determined as the correct point of attachment between the orbital septum and the levator aponeurosis.5 Precisely evaluating the inferior extension of the preaponeurotic fat pad in cadavers is difficult, because soft tissue shrinks by approximately 15% from its original size when fixed with formalin.7 The preaponeurotic fat probably also © 2009 by the American Academy of Ophthalmology Published by Elsevier Inc.
shrinks in formalin-fixed cadavers; hence, such measurements may be performed better in vivo. The aim of this study was to examine the anatomic relationships between the orbital septum, DEALLA, and the preaponeurotic fat pad and the superior tarsal border both in vivo (during upper blepharoplasty) and in dissected cadavers, where to the best of the authors’ knowledge, it has not been studied previously. The anatomic terms used in this article are listed in Table 1. Table 2 summarizes some of the studies that account for the fuller appearance in Asian and white eyelids, including the distance of the DEALLA from the superior tarsal border.2,3,8 –12
Patients and Methods The first group (in vivo study) included 22 upper eyelids in 11 patients (4 males, 7 females) with dermatochalasis who underwent blepharoplasty. The overall average age was 76.5 years (range, 49 – 89 years). The average age in males was 72 years (range, 49 – 88 years), and that in females was 79 years (range, 69 – 89 years). Patients who underwent any previous eyelid surgeries were excluded from the study. Ethical approval was obtained from the local institutional review board, and all patients gave informed consent. ISSN 0161-6420/09/$–see front matter doi:10.1016/j.ophtha.2009.04.005
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Ophthalmology Volume 116, Number 10, October 2009 Table 1. Anatomic Terms Distal end of the anterior layer of the levator aponeurosis: This is located at the junction with the orbital septum. Because the anterior layer of the levator aponeurosis is a white fibrous tissue, the distal edge of it is seen as a white line through the orbital septum. Superior tarsal border: The superior edge of the upper tarsal plate. Levator aponeurosis: The tendon of the levator palpebrae superioris muscle, which is made of layers, an anterior and a posterior layer. Preaponeurotic fat pad: The orbital fat located in front of the levator aponeurosis. This fat is covered anteriorly by the orbital septum. Orbital septum: A fibrous sheet located between the submuscular fibroadipose tissue and the preaponeurotic fat pad. The septum originates from the orbital rim and inserts on the levator aponeurosis. Submuscular fibroadipose tissue: Fibers with rich adipose tissue located behind the orbicularis oculi muscle (also referred to as the suborbicularis tissue). Conjoined fascia: The distal part of the levator aponeurosis after joining the orbital septum.
The first step in the surgical procedure was to quantify the redundant skin volume using the pinch technique.12 Half the vertical height of the skin from the skin pinch was removed (including skin and orbicularis oculi muscle) using a Colorado needle, taking care not to include the tissue under the orbicularis oculi muscle. The suborbicularis oculi muscle layer then was dissected and the wound edges gently were pulled superiorly to evaluate the anatomic relationships of the orbital septum, DEALLA, and the preaponeurotic fat pad with the superior tarsal border. To assure accurate identification of the DEALLA, the orbital septum was raised upward with forceps by withdrawing the preaponeurotic fat. The surgical technique used in the blepharoplasty patients did not allow exposure of the superior border of the tarsus to make any objective measurements. No local anesthesia was injected through the orbital septum into the fat pad before the measurement was made, and the effect of draping was eliminated carefully. All the procedures and measurements, performed by the same surgeon (HK), were carried out with the patients in the supine position and their eyes closed. The second group (cadaver dissection study) included 10 postmortem upper eyelid specimens of 7 Asians (4 eyelids in 2 males and 6 eyelids in 5 females) fixed in 10% buffered formalin and examined macroscopically. Four upper eyelids could not be studied because of tissue damages. Average patient age at death was 81 years (range, 73– 87 years). All cadavers were registered with the Aichi Medical University, and proper consent and approval was obtained before use. The methods for securing human tissue complied with the tenets of the Declaration of Helsinki. All the measurements were performed by the same observer (HK). The first step in dissection was removing the skin from the underlying orbicularis oculi muscle. The orbicularis oculi muscle then was detached from the suborbicularis oculi muscle layer, taking care not to penetrate the orbital septum. The upper half of the arcus marginalis was incised with a scalpel, and the preaponeurotic and medial fat pads, as well submuscular fibroadipose tissue, then were
removed as much as possible. The attachment site of the orbital septum on the levator aponeurosis was analyzed, both anteriorly and posteriorly. Then, the orbital septum was excised from the DEALLA, and the distance from the superior tarsal plate border to the DEALLA was measured at 3 points: the center of the palpebral width and the 2 points located 7 mm medial and lateral to the center. Statistical analysis was based on the Mann–Whitney U test. Statistical significance was defined as P⬍0.05. All statistical analysis was carried out using the Dr. SPSS for Windows (SPSS Japan Inc., Tokyo, Japan).
Results In vivo, the DEALLA was always located above the superior border of the tarsal plate (Fig 1A). The lower margin of the preaponeurotic fat reached below the DEALLA in all cases and was situated at the level of the superior tarsal plate border (Figure 1B). The lateral part of the fat in 4 eyelids (2 patients) extended beyond the superior tarsal plate border (Fig 1B). Careful study of the cadaveric specimens revealed no evidence of prior surgical manipulation, and no documentation of blepharoptosis was found in the past medical records of any donors. Analysis of the cadaver specimens from the anterior aspect showed 5 cases where the confluent part of the orbital septum was located as a distinct line on the levator aponeurosis above the superior border of the tarsal plate (Fig 2A, B). In the other 5 specimens, it was difficult to delineate the confluent part because the orbital septum and the levator aponeurosis join smoothly in the distal part to become the conjoined fascia (Fig 2C).13 Analysis from the posterior aspect showed that the orbital septum continued to the anterior layer of the levator aponeurosis (Fig 2D). After removal of the orbital septum, it was found that the distance from the superior tarsal plate border to the DEALLA was higher in the central area and lower in the lateral area in most cases (Fig 2E; Table 3). In 1 specimen, this distance was higher medially than centrally, and in 3 specimens, the distance in the lateral area was defined as negative, the attachment site being on the tarsal plate. The average distances were 3.0 mm in medial area, 3.7 mm in central area, and 0.9 mm laterally. Although there was no statistically significant difference between the distances in medial and central areas (P ⫽ 0.243), the distance in the lateral area was significantly lower than in the medial or the central area (P ⫽ 0.004 and P ⫽ 0.001, respectively). Figure 2F shows a diagram of the sagittal plane, and Figure 2G is a side-by-side sagittal section from the eyelid of a white person for comparison (stain, hematoxylin– eosin).
Discussion The results of this in vivo study in Asians suggest that the DEALLA is situated above the superior border of the tarsal plate and that the preaponeurotic fat extends beyond the DEALLA and is situated around the superior tarsus. The lateral part of the fat was located on the tarsal plate in 4 patients.
Table 2. Site of the Attachment of the Orbital Septum on the Levator Aponeurosis Author(s)
Year
Sayoc Doxanas and Anderson2 Meyer et al9 Tsurukiri10 Miyake et al11 Jeong et al3 McCurdy Jr12
1967 1984 1991 1992 1994 1999 2005
8
2032
Asians Below 26/30, above 4/30, below A few mm above Below Below
White Persons 10 mm above Above 2–5 mm above (average, 3.4 mm)
Above Above
Kakizaki et al 䡠 Orbital Septum Attachment in Asians
Figure 1. A, Photograph showing that the distal end of the anterior layer of the levator aponeurosis (DEALLA) is located above the superior border of the tarsal plate. B, Photograph showing that the preaponeurotic fat is situated above the DEALLA (see Fig 1A) and around the superior tarsal margin. In this specimen, the lateral part fat shows the extension above the superior tarsal plate border. This finding is more prominent when removing the superior pull by the hook.
Although a full appearance of the upper eyelid in Asians has been attributed to the inferior attachment of the orbital septum on the levator aponeurosis,1,2 as well as the rich submuscular fibroadipose tissue,2– 4 the major factor is probably the inferior prolapse of the orbital septum and the preaponeurotic fat pad. This is based on the findings that the DEALLA was always situated above the superior border of the tarsal plate, although the lower margin of the preaponeurotic fat reached below the DEALLA and was situated at the level of the superior tarsal plate border. It is possible that attenuation in the thickness of the inferior portion of the orbital septum in the Asian upper eyelid allows anterior–inferior migration of the preaponeurotic fat pad, but this factor was not studied. In cadavers, the attachment site of the orbital septum on the levator aponeurosis was found to be higher centrally and lower laterally. In some cases, the confluence was located on the tarsal plate in the lateral area. This finding emphasizes the importance of defining the specific area where the measurement was obtained when presenting the distance between the superior tarsal plate border and the DEALLA. The confluent part of the orbital septum and the levator aponeurosis is evaluated more accurately by incising the arcus marginalis with downward reflection of the orbital septum and removal of the preaponeurotic and medial fat pads. In this posterior approach, the orbital septum was found to continue inferiorly from the DEALLA, which has been shown to be the true attachment site between the orbital septum and the levator aponeurosis in Asians.5 Analyzing the attachment sites using the anterior view is sometimes misleading because the orbital septum merges smoothly with the posterior layer of the levator aponeurosis5 and becomes the conjoined fascia.13 In the in vivo study, the DEALLA always was situated above the superior tarsal plate border. In the histologic study, it was sometimes over the surface of the tarsal plate laterally. Because in vivo measurements were performed in patients undergoing blepharoplasty, examinations were limited by the degree of aggressive dissections. These dissections could be performed more easily in cadavers. The authors believe that the DEALLA identified during surgery always is analogous to the histologic DEALLA and that the findings in this study are not just a result of the sample size or a postmortem change.
Previous studies dealing with the attachment of the orbital septum on the levator aponeurosis in Asians were strongly influenced by previous studies in white persons.1,2 In these previous studies, the exact location of the confluence part was judged based on the anterior view of gross cadaveric anatomic features,3 and the studies were carried out using the protruded site of the preaponeurotic fat pad in microscopic anatomic features.3 In addition, the submuscular fibroadipose tissue occasionally was confused with the preaponeurotic fat pad.2 These factors may have precluded an accurate identification of the junction of the orbital septum and the levator aponeurosis in Asian eyelids. Magnetic resonance imaging (MRI) also has been used to determine the attachment site of the orbital septum on the levator aponeurosis.3 However, this method may not be ideal for this purpose in Asians because the larger volume of the preaponeurotic fat pad in this population makes it difficult to determine the point of confluence, and the DEALLA cannot be delineated exactly. The Asian upper eyelid crease is known to be lower or less distinctly defined. This may be caused by the inferior extension of the preaponeurotic fat pad interrupting the superficially extending levator aponeurosis fibers.2,3 In addition, because the height of the upper tarsal plate in Asians is smaller than that in white persons,14,15 the preaponeurotic fat pad can extend further inferiorly, which also may contribute to the typical Asian upper eyelid appearance, to which the thick suborbicularis tissue contributes as well.2– 4 A study using the same techniques of investigation for the anatomy of both Asian and non-Asian eyelids may delineate better the anatomic differences and may explain the racial differences in the location of the eyelid crease. It is generally stated that historically, the differences in the clinical appearance of the eyelid crease in Asian and white eyelids have been attributed to an anatomic difference in the relationship between the orbital septum and levator aponeurosis.2 However, the basic structures are very similar.16 –18 For example, in both Asians and white persons, the confluent part of the orbital septum and the levator aponeurosis in the central area is always situated above the superior tarsal plate border.16 The average distance from the superior tarsal plate border to the DEALLA in the central area in
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Ophthalmology Volume 116, Number 10, October 2009
Figure 2. A, Anterior view in a cadaver showing the confluent part between the orbital septum and the levator aponeurosis located above the superior border of the tarsal plate. B, The same findings as in Figure 2A, with the arcus marginalis incised. C, It is difficult from the anterior view to determine the confluent part in some samples because the orbital septum and the levator aponeurosis smoothly join and become the conjoined fascia. D, The orbital septum is turned downward and the preaponeurotic space is seen behind the orbital septum. With this view, the orbital septum continues from the distal end of the anterior layer of the levator aponeurosis (DEALLA). E, The distance from the superior tarsal plate border to the DEALLA is larger in the medial and central areas than in the lateral area. F, Diagram of an Asian eyelid in the sagittal plane across center of pupil. G, A side-by-side sagittal section across the center of the pupil of an eyelid from a white person. The cadaver of this sample was registered with the University of Adelaide, where proper consents and approvals were obtained before use. The method for securing human tissue was humane and complied with the tenets of the Declaration of Helsinki (stain, hematoxylin– eosin; bar, 3 mm; original magnification ⫻ 20).
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Kakizaki et al 䡠 Orbital Septum Attachment in Asians Table 3. Distance (in millimeters) from the Superior Tarsal End to the Distal End of the Anterior Layer of the Levator Aponeurosis Case No.
Medial
Central
Lateral
1 2 3 4 5 6 7 8 9 10 Mean⫾standard deviation
3.9 2.7 3.4 2.6 1.2 2.1 4.8 4.3 2.3 2.8 3.0⫾1.1
3.4 3.5 4.3 3.4 2.4 2.4 5.6 5.2 2.8 3.5 3.7⫾1.1
1.1 0.6 1.3 –0.3 –0.5 0 3.4 3 –0.2 0.8 0.9⫾1.4
white persons was approximately 3.4 mm,9 similar to what was found in this study. Hence, one of the major differences between these races may be the fat volume in the preaponeurotic area, which occasionally affects the eyelid appearance and makes it difficult to identify the correct site of confluence between the septum and aponeurosis. It should be noted that the in vivo examinations were carried out in a selected group of older individuals undergoing blepharoplasty for dermatochalasis, and that the cadaveric study also examined an older age group. It therefore is possible that gravitational or involutional changes in upper eyelid structures might have influenced these findings. In conclusion, the confluent part of the orbital septum and the levator aponeurosis in Asian patients was located above the superior border of the upper tarsal plate, and the preaponeurotic fat extended beyond the DEALLA, sometimes reaching the tarsal plate. In cadavers, the confluent part of the orbital septum and the levator aponeurosis was highest centrally but lowest laterally and was, on occasion, situated on the tarsal plate. Judging the confluent site of the orbital septum and the levator aponeurosis in Asians, based on the inferior end of the preaponeurotic fat pad, probably is not accurate and probably should be evaluated based on the DEALLA.
2. 3. 4. 5. 6. 7.
8. 9.
10. 11. 12. 13. 14. 15. 16. 17.
References
18. 1. Jordan DR, Anderson RL. Surgical Anatomy of the Ocular Adnexa: A Clinical Approach. San Francisco: American
Academy of Ophthalmology; 1996:16 –17. Ophthalmology Monographs 9. Doxanas MT, Anderson RL. Oriental eyelids: an anatomic study. Arch Ophthalmol 1984;102:1232–5. Jeong S, Lemke BN, Dortzbach RK, et al. The Asian upper eyelid: an anatomical study with comparison to the Caucasian eyelid. Arch Ophthalmol 1999;117:907–12. Ichinose A, Tahara S. Extended preseptal fat resection in Asian blepharoplasty. Ann Plast Surg 2008;60:121– 6. Kakizaki H, Zako M, Nakano T, et al. The levator aponeurosis consists of two layers that include smooth muscle. Ophthal Plast Reconstr Surg 2005;21:379 – 82. Hwang K, Kim DJ, Chung RS, et al. An anatomical study of the junction of the orbital septum and the levator aponeurosis in Orientals. Br J Plast Surg 1998;51:594 – 8. Boonstra H, Oosterhuis JW, Oosterhuis AM, et al. Cervical tissue shrinkage by formaldehyde fixation, paraffin wax embedding, section cutting and mounting. Virchows Arch A Pathol Anat Histopathol 1983;402:195–201. Sayoc BT. Anatomic considerations in the plastic construction of a palpebral fold in the full upper eyelid. Am J Ophthalmol 1967;63:155– 8. Meyer DR, Linberg JV, Wobig JL, McCormick SA. Anatomy of the orbital septum and associated eyelid connective tissues: implications for ptosis surgery. Ophthal Plast Reconstr Surg 1991;7:104 –13. Tsurukiri K. Anatomy of upper lid (histological examination of a sagittal section through the upper lid). J Jpn Soc Aesthetic Plast Surg 1992;14:137– 47. Miyake I, Tange I, Hiraga Y. MRI findings of the upper eyelid and their relationship with single- and double-eyelid formation. Aesth Plast Surg 1994;18:183–7. McCurdy JA Jr. Upper blepharoplasty in the Asian patient: the “double eyelid” operation. Facial Plast Surg Clin North Am 2005;13:47– 64. Siegel R. Surgical anatomy of the upper eyelid fascia. Ann Plast Surg 1984;13:263–73. Whitnall SE. Anatomy of the Human Orbit and Accessory Organs of Vision. 2nd ed (reprint). Huntington, NY: Krieger; 1979:151. Chen WP. Concept of triangular, trapezoidal, and rectangular debulking of eyelid tissues: application in Asian blepharoplasty. Plast Reconstr Surg 1996;97:212– 8. Hawes MJ, Dortzbach RK. The microscopic anatomy of the lower eyelid retractors. Arch Ophthalmol 1982;100:1313– 8. Kakizaki H, Jinsong Z, Zako M, et al. Microscopic anatomy of Asian lower eyelids. Ophthal Plast Reconstr Surg 2006;22:430–3. Lim WK, Rajendran K, Choo CT. Microscopic anatomy of the lower eyelid in Asians. Ophthal Plast Reconstr Surg 2004;20: 207–11.
Footnotes and Financial Disclosures Originally received: December 7, 2008. Final revision: March 7, 2009. Accepted: April 1, 2009. Available online: July 9, 2009. 1
4
Manuscript no. 2008-1458.
Department of Ophthalmology, Aichi Medical University, Aichi, Japan.
2
Division of Oculoplastic and Orbital Surgery, Department of Ophthalmology, Tel-Aviv Medical Center, Tel-Aviv University, Tel-Aviv, Israel. 3
South Australian Institute of Ophthalmology and Discipline of Ophthalmology and Visual Sciences, University of Adelaide, Adelaide, Australia.
Department of Anatomy, Aichi Medical University, Aichi, Japan.
Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. Correspondence: Hirohiko Kakizaki, MD, PhD, Department of Ophthalmology, Aichi Medical University, Nagakute, Aichi 480-1195, Japan. E-mail: cosme@ d1.dion.ne.jp.
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The attachment of the orbital septum to the levator aponeurosis in Asians is thought to be lower than that in white persons, usually extending to the tarsal plate.1–3 This may explain an inferior extension of the preaponeurotic fat pad in Asians, which together with a thicker suborbicularis tissue creates a prominent upper eyelid fold and a fullerappearing eyelid.1– 4 It also has been postulated that the inferior extension of the orbital septum may block the superficial fibers of the anterior levator aponeurosis that normally form the eyelid crease, thereby creating a lower or a less distinctly formed eyelid crease.1 Microscopic anatomic studies in Asian upper eyelids have shown recently, however, that the confluent part of the orbital septum on the levator aponeurosis is located above the superior border of the tarsal plate.5 Because the orbital septum has a certain thickness and a layered structure,6 the distal end of the anterior layer of the levator aponeurosis (DEALLA) was determined as the correct point of attachment between the orbital septum and the levator aponeurosis.5 Precisely evaluating the inferior extension of the preaponeurotic fat pad in cadavers is difficult, because soft tissue shrinks by approximately 15% from its original size when fixed with formalin.7 The preaponeurotic fat probably also © 2009 by the American Academy of Ophthalmology Published by Elsevier Inc.
shrinks in formalin-fixed cadavers; hence, such measurements may be performed better in vivo. The aim of this study was to examine the anatomic relationships between the orbital septum, DEALLA, and the preaponeurotic fat pad and the superior tarsal border both in vivo (during upper blepharoplasty) and in dissected cadavers, where to the best of the authors’ knowledge, it has not been studied previously. The anatomic terms used in this article are listed in Table 1. Table 2 summarizes some of the studies that account for the fuller appearance in Asian and white eyelids, including the distance of the DEALLA from the superior tarsal border.2,3,8 –12
Patients and Methods The first group (in vivo study) included 22 upper eyelids in 11 patients (4 males, 7 females) with dermatochalasis who underwent blepharoplasty. The overall average age was 76.5 years (range, 49 – 89 years). The average age in males was 72 years (range, 49 – 88 years), and that in females was 79 years (range, 69 – 89 years). Patients who underwent any previous eyelid surgeries were excluded from the study. Ethical approval was obtained from the local institutional review board, and all patients gave informed consent. ISSN 0161-6420/09/$–see front matter doi:10.1016/j.ophtha.2009.04.005
2031
Ophthalmology Volume 116, Number 10, October 2009 Table 1. Anatomic Terms Distal end of the anterior layer of the levator aponeurosis: This is located at the junction with the orbital septum. Because the anterior layer of the levator aponeurosis is a white fibrous tissue, the distal edge of it is seen as a white line through the orbital septum. Superior tarsal border: The superior edge of the upper tarsal plate. Levator aponeurosis: The tendon of the levator palpebrae superioris muscle, which is made of layers, an anterior and a posterior layer. Preaponeurotic fat pad: The orbital fat located in front of the levator aponeurosis. This fat is covered anteriorly by the orbital septum. Orbital septum: A fibrous sheet located between the submuscular fibroadipose tissue and the preaponeurotic fat pad. The septum originates from the orbital rim and inserts on the levator aponeurosis. Submuscular fibroadipose tissue: Fibers with rich adipose tissue located behind the orbicularis oculi muscle (also referred to as the suborbicularis tissue). Conjoined fascia: The distal part of the levator aponeurosis after joining the orbital septum.
The first step in the surgical procedure was to quantify the redundant skin volume using the pinch technique.12 Half the vertical height of the skin from the skin pinch was removed (including skin and orbicularis oculi muscle) using a Colorado needle, taking care not to include the tissue under the orbicularis oculi muscle. The suborbicularis oculi muscle layer then was dissected and the wound edges gently were pulled superiorly to evaluate the anatomic relationships of the orbital septum, DEALLA, and the preaponeurotic fat pad with the superior tarsal border. To assure accurate identification of the DEALLA, the orbital septum was raised upward with forceps by withdrawing the preaponeurotic fat. The surgical technique used in the blepharoplasty patients did not allow exposure of the superior border of the tarsus to make any objective measurements. No local anesthesia was injected through the orbital septum into the fat pad before the measurement was made, and the effect of draping was eliminated carefully. All the procedures and measurements, performed by the same surgeon (HK), were carried out with the patients in the supine position and their eyes closed. The second group (cadaver dissection study) included 10 postmortem upper eyelid specimens of 7 Asians (4 eyelids in 2 males and 6 eyelids in 5 females) fixed in 10% buffered formalin and examined macroscopically. Four upper eyelids could not be studied because of tissue damages. Average patient age at death was 81 years (range, 73– 87 years). All cadavers were registered with the Aichi Medical University, and proper consent and approval was obtained before use. The methods for securing human tissue complied with the tenets of the Declaration of Helsinki. All the measurements were performed by the same observer (HK). The first step in dissection was removing the skin from the underlying orbicularis oculi muscle. The orbicularis oculi muscle then was detached from the suborbicularis oculi muscle layer, taking care not to penetrate the orbital septum. The upper half of the arcus marginalis was incised with a scalpel, and the preaponeurotic and medial fat pads, as well submuscular fibroadipose tissue, then were
removed as much as possible. The attachment site of the orbital septum on the levator aponeurosis was analyzed, both anteriorly and posteriorly. Then, the orbital septum was excised from the DEALLA, and the distance from the superior tarsal plate border to the DEALLA was measured at 3 points: the center of the palpebral width and the 2 points located 7 mm medial and lateral to the center. Statistical analysis was based on the Mann–Whitney U test. Statistical significance was defined as P⬍0.05. All statistical analysis was carried out using the Dr. SPSS for Windows (SPSS Japan Inc., Tokyo, Japan).
Results In vivo, the DEALLA was always located above the superior border of the tarsal plate (Fig 1A). The lower margin of the preaponeurotic fat reached below the DEALLA in all cases and was situated at the level of the superior tarsal plate border (Figure 1B). The lateral part of the fat in 4 eyelids (2 patients) extended beyond the superior tarsal plate border (Fig 1B). Careful study of the cadaveric specimens revealed no evidence of prior surgical manipulation, and no documentation of blepharoptosis was found in the past medical records of any donors. Analysis of the cadaver specimens from the anterior aspect showed 5 cases where the confluent part of the orbital septum was located as a distinct line on the levator aponeurosis above the superior border of the tarsal plate (Fig 2A, B). In the other 5 specimens, it was difficult to delineate the confluent part because the orbital septum and the levator aponeurosis join smoothly in the distal part to become the conjoined fascia (Fig 2C).13 Analysis from the posterior aspect showed that the orbital septum continued to the anterior layer of the levator aponeurosis (Fig 2D). After removal of the orbital septum, it was found that the distance from the superior tarsal plate border to the DEALLA was higher in the central area and lower in the lateral area in most cases (Fig 2E; Table 3). In 1 specimen, this distance was higher medially than centrally, and in 3 specimens, the distance in the lateral area was defined as negative, the attachment site being on the tarsal plate. The average distances were 3.0 mm in medial area, 3.7 mm in central area, and 0.9 mm laterally. Although there was no statistically significant difference between the distances in medial and central areas (P ⫽ 0.243), the distance in the lateral area was significantly lower than in the medial or the central area (P ⫽ 0.004 and P ⫽ 0.001, respectively). Figure 2F shows a diagram of the sagittal plane, and Figure 2G is a side-by-side sagittal section from the eyelid of a white person for comparison (stain, hematoxylin– eosin).
Discussion The results of this in vivo study in Asians suggest that the DEALLA is situated above the superior border of the tarsal plate and that the preaponeurotic fat extends beyond the DEALLA and is situated around the superior tarsus. The lateral part of the fat was located on the tarsal plate in 4 patients.
Table 2. Site of the Attachment of the Orbital Septum on the Levator Aponeurosis Author(s)
Year
Sayoc Doxanas and Anderson2 Meyer et al9 Tsurukiri10 Miyake et al11 Jeong et al3 McCurdy Jr12
1967 1984 1991 1992 1994 1999 2005
8
2032
Asians Below 26/30, above 4/30, below A few mm above Below Below
White Persons 10 mm above Above 2–5 mm above (average, 3.4 mm)
Above Above
Kakizaki et al 䡠 Orbital Septum Attachment in Asians
Figure 1. A, Photograph showing that the distal end of the anterior layer of the levator aponeurosis (DEALLA) is located above the superior border of the tarsal plate. B, Photograph showing that the preaponeurotic fat is situated above the DEALLA (see Fig 1A) and around the superior tarsal margin. In this specimen, the lateral part fat shows the extension above the superior tarsal plate border. This finding is more prominent when removing the superior pull by the hook.
Although a full appearance of the upper eyelid in Asians has been attributed to the inferior attachment of the orbital septum on the levator aponeurosis,1,2 as well as the rich submuscular fibroadipose tissue,2– 4 the major factor is probably the inferior prolapse of the orbital septum and the preaponeurotic fat pad. This is based on the findings that the DEALLA was always situated above the superior border of the tarsal plate, although the lower margin of the preaponeurotic fat reached below the DEALLA and was situated at the level of the superior tarsal plate border. It is possible that attenuation in the thickness of the inferior portion of the orbital septum in the Asian upper eyelid allows anterior–inferior migration of the preaponeurotic fat pad, but this factor was not studied. In cadavers, the attachment site of the orbital septum on the levator aponeurosis was found to be higher centrally and lower laterally. In some cases, the confluence was located on the tarsal plate in the lateral area. This finding emphasizes the importance of defining the specific area where the measurement was obtained when presenting the distance between the superior tarsal plate border and the DEALLA. The confluent part of the orbital septum and the levator aponeurosis is evaluated more accurately by incising the arcus marginalis with downward reflection of the orbital septum and removal of the preaponeurotic and medial fat pads. In this posterior approach, the orbital septum was found to continue inferiorly from the DEALLA, which has been shown to be the true attachment site between the orbital septum and the levator aponeurosis in Asians.5 Analyzing the attachment sites using the anterior view is sometimes misleading because the orbital septum merges smoothly with the posterior layer of the levator aponeurosis5 and becomes the conjoined fascia.13 In the in vivo study, the DEALLA always was situated above the superior tarsal plate border. In the histologic study, it was sometimes over the surface of the tarsal plate laterally. Because in vivo measurements were performed in patients undergoing blepharoplasty, examinations were limited by the degree of aggressive dissections. These dissections could be performed more easily in cadavers. The authors believe that the DEALLA identified during surgery always is analogous to the histologic DEALLA and that the findings in this study are not just a result of the sample size or a postmortem change.
Previous studies dealing with the attachment of the orbital septum on the levator aponeurosis in Asians were strongly influenced by previous studies in white persons.1,2 In these previous studies, the exact location of the confluence part was judged based on the anterior view of gross cadaveric anatomic features,3 and the studies were carried out using the protruded site of the preaponeurotic fat pad in microscopic anatomic features.3 In addition, the submuscular fibroadipose tissue occasionally was confused with the preaponeurotic fat pad.2 These factors may have precluded an accurate identification of the junction of the orbital septum and the levator aponeurosis in Asian eyelids. Magnetic resonance imaging (MRI) also has been used to determine the attachment site of the orbital septum on the levator aponeurosis.3 However, this method may not be ideal for this purpose in Asians because the larger volume of the preaponeurotic fat pad in this population makes it difficult to determine the point of confluence, and the DEALLA cannot be delineated exactly. The Asian upper eyelid crease is known to be lower or less distinctly defined. This may be caused by the inferior extension of the preaponeurotic fat pad interrupting the superficially extending levator aponeurosis fibers.2,3 In addition, because the height of the upper tarsal plate in Asians is smaller than that in white persons,14,15 the preaponeurotic fat pad can extend further inferiorly, which also may contribute to the typical Asian upper eyelid appearance, to which the thick suborbicularis tissue contributes as well.2– 4 A study using the same techniques of investigation for the anatomy of both Asian and non-Asian eyelids may delineate better the anatomic differences and may explain the racial differences in the location of the eyelid crease. It is generally stated that historically, the differences in the clinical appearance of the eyelid crease in Asian and white eyelids have been attributed to an anatomic difference in the relationship between the orbital septum and levator aponeurosis.2 However, the basic structures are very similar.16 –18 For example, in both Asians and white persons, the confluent part of the orbital septum and the levator aponeurosis in the central area is always situated above the superior tarsal plate border.16 The average distance from the superior tarsal plate border to the DEALLA in the central area in
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Ophthalmology Volume 116, Number 10, October 2009
Figure 2. A, Anterior view in a cadaver showing the confluent part between the orbital septum and the levator aponeurosis located above the superior border of the tarsal plate. B, The same findings as in Figure 2A, with the arcus marginalis incised. C, It is difficult from the anterior view to determine the confluent part in some samples because the orbital septum and the levator aponeurosis smoothly join and become the conjoined fascia. D, The orbital septum is turned downward and the preaponeurotic space is seen behind the orbital septum. With this view, the orbital septum continues from the distal end of the anterior layer of the levator aponeurosis (DEALLA). E, The distance from the superior tarsal plate border to the DEALLA is larger in the medial and central areas than in the lateral area. F, Diagram of an Asian eyelid in the sagittal plane across center of pupil. G, A side-by-side sagittal section across the center of the pupil of an eyelid from a white person. The cadaver of this sample was registered with the University of Adelaide, where proper consents and approvals were obtained before use. The method for securing human tissue was humane and complied with the tenets of the Declaration of Helsinki (stain, hematoxylin– eosin; bar, 3 mm; original magnification ⫻ 20).
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Kakizaki et al 䡠 Orbital Septum Attachment in Asians Table 3. Distance (in millimeters) from the Superior Tarsal End to the Distal End of the Anterior Layer of the Levator Aponeurosis Case No.
Medial
Central
Lateral
1 2 3 4 5 6 7 8 9 10 Mean⫾standard deviation
3.9 2.7 3.4 2.6 1.2 2.1 4.8 4.3 2.3 2.8 3.0⫾1.1
3.4 3.5 4.3 3.4 2.4 2.4 5.6 5.2 2.8 3.5 3.7⫾1.1
1.1 0.6 1.3 –0.3 –0.5 0 3.4 3 –0.2 0.8 0.9⫾1.4
white persons was approximately 3.4 mm,9 similar to what was found in this study. Hence, one of the major differences between these races may be the fat volume in the preaponeurotic area, which occasionally affects the eyelid appearance and makes it difficult to identify the correct site of confluence between the septum and aponeurosis. It should be noted that the in vivo examinations were carried out in a selected group of older individuals undergoing blepharoplasty for dermatochalasis, and that the cadaveric study also examined an older age group. It therefore is possible that gravitational or involutional changes in upper eyelid structures might have influenced these findings. In conclusion, the confluent part of the orbital septum and the levator aponeurosis in Asian patients was located above the superior border of the upper tarsal plate, and the preaponeurotic fat extended beyond the DEALLA, sometimes reaching the tarsal plate. In cadavers, the confluent part of the orbital septum and the levator aponeurosis was highest centrally but lowest laterally and was, on occasion, situated on the tarsal plate. Judging the confluent site of the orbital septum and the levator aponeurosis in Asians, based on the inferior end of the preaponeurotic fat pad, probably is not accurate and probably should be evaluated based on the DEALLA.
2. 3. 4. 5. 6. 7.
8. 9.
10. 11. 12. 13. 14. 15. 16. 17.
References
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Academy of Ophthalmology; 1996:16 –17. Ophthalmology Monographs 9. Doxanas MT, Anderson RL. Oriental eyelids: an anatomic study. Arch Ophthalmol 1984;102:1232–5. Jeong S, Lemke BN, Dortzbach RK, et al. The Asian upper eyelid: an anatomical study with comparison to the Caucasian eyelid. Arch Ophthalmol 1999;117:907–12. Ichinose A, Tahara S. Extended preseptal fat resection in Asian blepharoplasty. Ann Plast Surg 2008;60:121– 6. Kakizaki H, Zako M, Nakano T, et al. The levator aponeurosis consists of two layers that include smooth muscle. Ophthal Plast Reconstr Surg 2005;21:379 – 82. Hwang K, Kim DJ, Chung RS, et al. An anatomical study of the junction of the orbital septum and the levator aponeurosis in Orientals. Br J Plast Surg 1998;51:594 – 8. Boonstra H, Oosterhuis JW, Oosterhuis AM, et al. Cervical tissue shrinkage by formaldehyde fixation, paraffin wax embedding, section cutting and mounting. Virchows Arch A Pathol Anat Histopathol 1983;402:195–201. Sayoc BT. Anatomic considerations in the plastic construction of a palpebral fold in the full upper eyelid. Am J Ophthalmol 1967;63:155– 8. Meyer DR, Linberg JV, Wobig JL, McCormick SA. Anatomy of the orbital septum and associated eyelid connective tissues: implications for ptosis surgery. Ophthal Plast Reconstr Surg 1991;7:104 –13. Tsurukiri K. Anatomy of upper lid (histological examination of a sagittal section through the upper lid). J Jpn Soc Aesthetic Plast Surg 1992;14:137– 47. Miyake I, Tange I, Hiraga Y. MRI findings of the upper eyelid and their relationship with single- and double-eyelid formation. Aesth Plast Surg 1994;18:183–7. McCurdy JA Jr. Upper blepharoplasty in the Asian patient: the “double eyelid” operation. Facial Plast Surg Clin North Am 2005;13:47– 64. Siegel R. Surgical anatomy of the upper eyelid fascia. Ann Plast Surg 1984;13:263–73. Whitnall SE. Anatomy of the Human Orbit and Accessory Organs of Vision. 2nd ed (reprint). Huntington, NY: Krieger; 1979:151. Chen WP. Concept of triangular, trapezoidal, and rectangular debulking of eyelid tissues: application in Asian blepharoplasty. Plast Reconstr Surg 1996;97:212– 8. Hawes MJ, Dortzbach RK. The microscopic anatomy of the lower eyelid retractors. Arch Ophthalmol 1982;100:1313– 8. Kakizaki H, Jinsong Z, Zako M, et al. Microscopic anatomy of Asian lower eyelids. Ophthal Plast Reconstr Surg 2006;22:430–3. Lim WK, Rajendran K, Choo CT. Microscopic anatomy of the lower eyelid in Asians. Ophthal Plast Reconstr Surg 2004;20: 207–11.
Footnotes and Financial Disclosures Originally received: December 7, 2008. Final revision: March 7, 2009. Accepted: April 1, 2009. Available online: July 9, 2009. 1
4
Manuscript no. 2008-1458.
Department of Ophthalmology, Aichi Medical University, Aichi, Japan.
2
Division of Oculoplastic and Orbital Surgery, Department of Ophthalmology, Tel-Aviv Medical Center, Tel-Aviv University, Tel-Aviv, Israel. 3
South Australian Institute of Ophthalmology and Discipline of Ophthalmology and Visual Sciences, University of Adelaide, Adelaide, Australia.
Department of Anatomy, Aichi Medical University, Aichi, Japan.
Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. Correspondence: Hirohiko Kakizaki, MD, PhD, Department of Ophthalmology, Aichi Medical University, Nagakute, Aichi 480-1195, Japan. E-mail: cosme@ d1.dion.ne.jp.
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