Advertisement

Analysis of eyelid and eyebrow metrics in Iranian American adults

Open AccessPublished:October 06, 2022DOI:https://doi.org/10.1016/j.bjps.2022.08.067

      Summary

      Background

      Achieving patient satisfaction after oculofacial surgery requires sensitivity to ethnic anthropometric variation. While differences between the Caucasian and East Asian eyelid configurations are often discussed, there is a relative paucity of discussion related to characteristics of the Middle Eastern eyelid and periocular region. This study aims to understand differences between the eyelids and periocular region of patients of mixed Iranian extraction, versus those of mixed European descent.

      Methods

      In this cross-sectional cohort study, external photographs were collected from a prospectively maintained database at an oculofacial plastic surgery practice. Ethnicity, age, gender, and photographic data were extracted from patient charts. Iranian-American patients were compared to Caucasian-American patients. From full-face photographs, brow position (pupil-to-brow, PTB), eyelid position (margin-to-reflex distance 1 and 2, MRD1 and MRD2), and tarsal platform show (TPS) were analyzed. Mixed effect ANOVA modeling was employed.

      Results

      The Iranian-American eyelid complex was found to maintain a lower MRD1 (-0.34 mm, p < 0.01), higher MRD2 (+0.48 mm, p < 0.01), and longer TPS (+0.74 mm, p < 0.01) compared to Caucasian-American patients. Further, pupil-to-brow (PTB) distance was noted to be 1.46 mm higher (p < 0.01) in Iranian-Americans.

      Conclusion

      Patients with Iranian-American ethnicity, compared to those of mixed European extraction, demonstrate distinctive eyelid anthropometric features. An understanding of these features may help to guide aesthetic surgical planning.

      Keywords

      Introduction

      Many descriptions of anthropometric periocular features are focused on East Asian eyelids
      • Jeong S.
      • et al.
      The Asian upper eyelid: an anatomical study with comparison to the Caucasian eyelid.
      • Kiranantawat K.
      • Suhk J.H.
      • Nguyen A.H.
      The Asian eyelid: relevant anatomy.
      • Saonanon P.
      Update on Asian eyelid anatomy and clinical relevance.
      • Seiff S.R.
      • Seiff B.D.
      Anatomy of the Asian eyelid.
      • Yu L.
      Invited discussion on: anthropometry analysis of beautiful upper eyelids in oriental: new eyelid crease ratio and clinical application.
      • Burusapat C.
      • et al.
      Anthropometry analysis of beautiful upper eyelids in oriental: new eyelid crease ratio and clinical application.
      • Iwanami M.
      • Tsurukiri K.
      Histological comparison between young and aged specimens of the Oriental lower eyelid using sagittal serial sections.
      • Cheng J.
      • Xu F.Z.
      Anatomic microstructure of the upper eyelid in the Oriental double eyelid.
      • McCurdy Jr., J.A.
      Westernization of the oriental eyelid.
      • Chen W.P.
      • blepharoplasty Asian
      Update on anatomy and techniques.
      • Dharap A.S.
      • Reddy S.C.
      Upper eyelid and eyebrow dimensions in Malays.
      • Jayaratne Y.S.
      • Deutsch C.K.
      • Zwahlen R.A.
      Normative findings for periocular anthropometric measurements among Chinese young adults in Hong Kong.
      • Viveiros M.M.H.
      • et al.
      Eyelid fissure dimensions in Japanese and in Brazilians of European descent over 50 years of age.
      • Choi Y.
      • Kang H.G.
      • Nam Y.S.
      Three skin zones in the asian upper eyelid pertaining to the Asian blepharoplasty.
      • Millard Jr., D.R.
      The oriental eyelid and its surgical revision.
      and comparatively less has been written about the periocular measurements of other populations such as Turkish,
      • Ozturk F.
      • Yavas G.
      • Inan U.U.
      Normal periocular anthropometric measurements in the Turkish population.
      Indian,
      • Packiriswamy V.
      • Kumar P.
      • Bashour M.
      Photogrammetric analysis of eyebrow and upper eyelid dimensions in South Indians and Malaysian South Indians.
      • Sadacharan C.M.
      • Packirisamy V.
      Photogrammetric analysis of eyebrow and eyelid dimensions in Indian American adults.
      Black,
      • Pelletier A.T.
      • Few J.W.
      Eyebrow and eyelid dimensions: an anthropometric analysis of African Americans and caucasians.
      • Price K.M.
      • et al.
      Eyebrow and eyelid dimensions: an anthropometric analysis of African Americans and caucasians.
      and Latino
      • Fry C.L.
      • et al.
      The Latino eyelid: anthropometric analysis of a spectrum of findings.
      populations. Despite evidence from the rhinoplasty literature that specific morphologic features may be considered characteristic of Iranian populations,
      • Rohrich R.J.
      • Ghavami A.
      Rhinoplasty for Middle Eastern noses.
      • Ghorbani J.
      • et al.
      Structural characteristics of the Iranians nose: an anatomical analysis.
      little has been written regarding the periocular features of Iranians and other Middle Easterners.
      Among the prerequisites for achieving satisfactory results following eyelid surgery, particularly for East Asian patients, the preservation of “ethno-specific” facial features ranks paramount. For instance, upper eyelid procedures that deliberately avoid creating a long tarsal platform show (TPS) are, broadly speaking, preferred in East Asian patients, as a long TPS (i.e., high crease) is ostensibly less “ethno-specific” to that population as compared to European populations. Quantitative anthropometric data thus can be used as a guide in customizing each procedure to each patient's background and desires. A paucity of such anthropometric data is evident with respect to Middle Eastern faces, and the present study aims to fill that knowledge gap.

      Methods

      In this cross-sectional study, patients presenting to a single tertiary oculofacial plastic surgery practice in Los Angeles that serves a large expatriate Iranian population were screened for inclusion. Two groups of patients were selected: Iranian and Caucasian. In order to identify Iranian subjects, an institutional database was queried by surname. Common Iranian surnames were distinguished from other Middle Eastern surnames by suffix, including “zadeh”, “pour”, “bakhsh”, “far”, and “nejad.”. In order to identify individuals of Caucasian descent, the database was queried for typical Caucasian surnames, including “Thompson,” “Smith,” “Johnson,” “Miller,” and “Jones.” Institutional records were further assessed for documentation of self-reported ethnicity, where available. Patients in the Caucasian-American cohort were selected if they self-reported “White” or “Caucasian” ethnicity, and patients in the Iranian-American cohort were selected if they self-reported “Iranian” or “Middle Eastern” ancestry.
      Patients with a history of orbital disease, such as Graves’ orbitopathy, or history of other obvious facial deformities, such as upper eyelid ptosis, facial weakness due to facial palsy, orbito-facial trauma, and patients with a history of eyelid or brow surgery were excluded. Notes were examined to identify patients with stated history of facial botulinum toxin or periocular filler injection, and these patients were additionally excluded. Patients with photographically obvious frontalis elevation were excluded. Iranian-American and Caucasian-American patients were age matched within approximately 10 years and sex matched in an approximately 1:1 ratio.
      Frontal photographs obtained in repose with a neutral facial expression and the eyes in primary position were extracted. Image analysis was performed using ImageJ (National Institutes of Health, USA) software. Calibration of pixel to mm conversion was performed on each photograph using sex-specific average horizontal width of the cornea as a standard reference.
      • Rufer F.
      • Schroder A.
      • Erb C.
      White-to-white corneal diameter: normal values in healthy humans obtained with the Orbscan II topography system.
      Anthropometric measurements were performed including margin-to-reflex distance 1 (MRD1), margin-to-reflex distance 2 (MRD2), pupil-to-brow (PTB), and TPS. MRD1 and MRD2 were defined as the vertical distance from the geometric center of the pupil to the upper and lower eyelid margins, respectively. PTB was similarly defined as the vertical distance from the geometric center of the pupil to the lowest visible margin of the eyebrow cilia, and TPS was defined as the distance from the eyelid margin to lower border of the lowest upper eyelid fold.
      Paired, independent, and multivariate statistical analyses were performed using the R (© The R Foundation, Vienna, Austria) statistical package. Mixed effect ANOVA modeling was performed. Fixed effects in this model were ethnicity, age, and gender. Random effects were individual differences and laterality (left or right). The effect of ethnicity on MRD1, MRD2, TPS, and PTB was assessed in this series of models. This study was approved by the Institutional Review Board of the University of California, Los Angeles and was conducted in compliance with the Declaration of Helsinki and adhered to Health Insurance Portability and Accountability Act (HIPAA) guidelines.

      Results

      A total of 182 patients were included, including 83 Iranian-American and 99 Caucasian-American. Mean (SD) age was 46.22 y (11.11) for Iranian-Americans and 50.21 y (10.53) for Caucasian-Americans. There was no significant difference in age between the two groups (p = 0.16). Of the Iranian-American patients, 83% were female, and of the Caucasian-Americans, 78% were female; this difference was not significant (p = 0.29). A summary of the anthropometric measurements is provided in Table 1, and representative images are shown in Figure 1.
      Table 1Summary of measurements. Bold numbers indicate the greater mean value.
      IranianCaucasian
      Mean (mm)SDMean (mm)SD
      MRD13.410.753.70
      p < 0.01.
      0.67
      MRD25.76
      p < 0.01.
      0.955.290.83
      TPS5.12
      p < 0.01.
      1.644.371.88
      PTB15.41
      p < 0.01.
      2.6213.893.27
      SD = standard deviation.
      low asterisk p < 0.01.
      Figure 1
      Figure 1Representative images of Iranian-American configuration eyelids/brows (upper panel) versus those of Caucasian-Americans (lower panel). The upper panel, central panes, illustrates the measurements examined in this study. MRD1 (red) = margin-to-reflex distance 1, MRD2 (blue) = margin-to-reflex distance 2, TPS (green) = tarsal platform show, PTB (yellow) = pupil-to-brow distance.
      In multivariate analysis, when compared to Caucasian-Americans, Iranian-American ethnicity was a significant predictor of MRD1, MRD2, TPS, and PTB (Figure 2). Given a particular age and gender, a patient of Iranian-American descent was found to demonstrate a 0.34 mm lower MRD1 (p < 0.01), 0.48 mm greater MRD2 (p < 0.01), 0.74 mm longer TPS (p < 0.01), and 1.46 mm greater PTB (p < 0.01).
      Figure 2
      Figure 2MRD1, MRD2, TPS, and PTB were significantly different when comparing Iranian-American to Caucasian faces (mixed effects ANOVA model, *** = p < 0.01).

      Discussion

      The Iranian-American patients studied herein exhibited periocular features distinguishing them from Caucasian-Americans. Particularly, Iranian-Americans were measured to have more inferiorly positioned upper and lower eyelids (MRD1 and MRD2, respectively), longer TPS height, and PTB distance.
      Surgical planning in blepharoplasty surgery requires artistic decisions that benefit from an intimate understanding of population level anatomic differences. Data from the present investigation suggest that, compared to Caucasian-Americans, the Iranian-American phenotype is characterized by a relatively more ptotic upper eyelid and a longer TPS. Management of TPS has been shown to be one of the critical determining factors in patients’ perception of surgical success,
      • Goldberg R.A.
      • Lew H.
      Cosmetic outcome of posterior approach ptosis surgery (an American Ophthalmological Society thesis).
      particularly in the East Asian population.
      • Young S.M.
      • et al.
      Lowering of the high eyelid crease in revision upper eyelid surgery.
      More specifically, modern “Double Eyelid Surgery”
      • Lorden D.S.
      • et al.
      What is in a name? It is time to retire the term "Asian Blepharoplasty".
      for East Asian descent patients aims to increase TPS judiciously, that is, without raising the TPS to a level typical of a Caucasian eyelid. Based on this, one may argue that reconstructive and aesthetic blepharoplasty for Iranian descent patients could include measures that would lead to a somewhat greater TPS than would be typically observed in Caucasian patients. Such measures might include upper blepharoplasty incision design with the inferior border of the incision placed at a more superior position or, in select cases, might involve more liberal sculpting of the upper eyelid and anterior orbital fat, with higher tolerance for a deeper superior sulcus.
      Like TPS, PTB was found to be significantly greater in the Iranian-American population as compared to the Caucasian-American population. The anatomic reasons for this may be related to differences in brow ridge and orbital anatomy between Iranians and Caucasians or alternatively may be due to group differences in eyebrow hair density and grooming patterns. These two explanations are not mutually exclusive. In either case, similar to preserving slightly higher TPS during upper blepharoplasty, this finding suggests that an aesthetic surgeon considering interventions aimed at rejuvenating the eyebrow may wish to pay particular attention to creating a higher brow position in Iranian-American patients undergoing, for instance, surgical forehead lift. Conversely, chemo-denervation strategies that include relaxing the frontalis muscle and lowering the eyebrow may produce particularly undesirable brow depression in the Middle Eastern patient.
      The finding that Iranian-American patients demonstrate a larger MRD2, and thus a more inferiorly displaced lower eyelid margin has several possible anatomic explanations. One possibility is that these patients may on average have relatively less anterior projection of the body of the maxilla and inferior orbital rim. Negative midface vector has been associated with a more inferior eyelid margin position relative to the globe.
      • Rajabi M.T.
      • et al.
      A comparison of lower eyelid retraction in normal individuals with positive versus negative orbital vector.
      Similarly, a smaller volume orbit resulting in relative axial proptosis may also lead to such a phenotype. Future studies examining Caucasian versus Middle Eastern orbital volume, orbital aperture, axial globe position, and maxillary volumetric structure may reasonably be considered to better understand the anatomic basis of the greater MRD2 in Middle Eastern patients.
      One limitation of this study is that expatriate Iranians in Los Angeles,
      • Kelley R.
      • et al.
      the population from which the study sample was drawn, likely demonstrate a different composition of ethnic subgroups compared to Iranians living in Iran.
      • Mehrjoo Z.
      • et al.
      Distinct genetic variation and heterogeneity of the Iranian population.
      Thus, the conclusions drawn from the study of Los Angeles expatriate Iranians may not be firmly generalizable to the Iranian population at large. Another limitation of this study is that surname was used as a screening tool to identify patients of a given ethnicity, a strategy that does not take into account for intermarriage between Iranians and Caucasians. With respect to the two groups being compared, however, last name might be expected to be highly correlated with ethnicity, given the historically high rates of endogamy among Los Angeles dwelling expatriate Iranians.
      • Bozorgmehr M.
      Internal ethnicity: Iranians in Los Angeles.
      In summary, when compared to Caucasian-American patients, periocular anthropometric measurements in an Iranian-American population demonstrated several notable differences. The Iranian-American population tended to be characterized by a lower MRD1 and longer TPS, as well as higher brow position and longer MRD2. Data regarding such differences, to some extent representative of broader European descent and Middle Eastern populations as a whole, may impact the practice patterns of aesthetic oculofacial surgeons in their quest to make ethnically appropriate decisions before and during surgical and non-surgical upper face procedures.

      Funding

      This work is supported by an Unrestricted Grant from Research to Prevent Blindness, Inc. to the Department of Ophthalmology at UCLA.

      Ethical Approval

      This study was approved by the Institutional Review Board (IRB) of the University of California, Los Angeles and was conducted in compliance with the Declaration of Helsinki and adhered to Health Insurance Portability and Accountability Act (HIPAA) guidelines.

      Patient Consent

      Written informed consent was obtained from all patients whose photographs were included in this study's figures.

      Declaration of Competing Interest

      All authors report no conflicts of interest, financial, or otherwise. The authors alone are responsible for the content and writing of the paper.

      References

        • Jeong S.
        • et al.
        The Asian upper eyelid: an anatomical study with comparison to the Caucasian eyelid.
        Arch Ophthalmol. 1999; 117: 907-912
        • Kiranantawat K.
        • Suhk J.H.
        • Nguyen A.H.
        The Asian eyelid: relevant anatomy.
        Semin Plast Surg. 2015; 29: 158-164
        • Saonanon P.
        Update on Asian eyelid anatomy and clinical relevance.
        Curr Opin Ophthalmol. 2014; 25: 436-442
        • Seiff S.R.
        • Seiff B.D.
        Anatomy of the Asian eyelid.
        Facial Plast Surg Clin North Am. 2007; 15 (v): 309-314
        • Yu L.
        Invited discussion on: anthropometry analysis of beautiful upper eyelids in oriental: new eyelid crease ratio and clinical application.
        Aesthetic Plast Surg. 2020;
        • Burusapat C.
        • et al.
        Anthropometry analysis of beautiful upper eyelids in oriental: new eyelid crease ratio and clinical application.
        Aesthetic Plast Surg. 2020; 44: 392-410
        • Iwanami M.
        • Tsurukiri K.
        Histological comparison between young and aged specimens of the Oriental lower eyelid using sagittal serial sections.
        Plast Reconstr Surg. 2007; 119: 2061-2071
        • Cheng J.
        • Xu F.Z.
        Anatomic microstructure of the upper eyelid in the Oriental double eyelid.
        Plast Reconstr Surg. 2001; 107: 1665-1668
        • McCurdy Jr., J.A.
        Westernization of the oriental eyelid.
        Otolaryngol Head Neck Surg. 1982; 90: 142-145
        • Chen W.P.
        • blepharoplasty Asian
        Update on anatomy and techniques.
        Ophthalmic Plast Reconstr Surg. 1987; 3: 135-140
        • Dharap A.S.
        • Reddy S.C.
        Upper eyelid and eyebrow dimensions in Malays.
        Med J Malaysia. 1995; 50: 377-381
        • Jayaratne Y.S.
        • Deutsch C.K.
        • Zwahlen R.A.
        Normative findings for periocular anthropometric measurements among Chinese young adults in Hong Kong.
        Biomed Res Int. 2013; (2013)821428
        • Viveiros M.M.H.
        • et al.
        Eyelid fissure dimensions in Japanese and in Brazilians of European descent over 50 years of age.
        Arq Bras Oftalmol. 2017; 80: 304-308
        • Choi Y.
        • Kang H.G.
        • Nam Y.S.
        Three skin zones in the asian upper eyelid pertaining to the Asian blepharoplasty.
        J Craniofac Surg. 2017; 28: 892-897
        • Millard Jr., D.R.
        The oriental eyelid and its surgical revision.
        Am J Ophthalmol. 1964; 57: 646-649
        • Ozturk F.
        • Yavas G.
        • Inan U.U.
        Normal periocular anthropometric measurements in the Turkish population.
        Ophthalmic Epidemiol. 2006; 13: 145-149
        • Packiriswamy V.
        • Kumar P.
        • Bashour M.
        Photogrammetric analysis of eyebrow and upper eyelid dimensions in South Indians and Malaysian South Indians.
        Aesthet Surg J. 2013; 33: 975-982
        • Sadacharan C.M.
        • Packirisamy V.
        Photogrammetric analysis of eyebrow and eyelid dimensions in Indian American adults.
        J Craniofac Surg. 2020;
        • Pelletier A.T.
        • Few J.W.
        Eyebrow and eyelid dimensions: an anthropometric analysis of African Americans and caucasians.
        Plast Reconstr Surg. 2010; 125: 1293-1294
        • Price K.M.
        • et al.
        Eyebrow and eyelid dimensions: an anthropometric analysis of African Americans and caucasians.
        Plast Reconstr Surg. 2009; 124: 615-623
        • Fry C.L.
        • et al.
        The Latino eyelid: anthropometric analysis of a spectrum of findings.
        Ophthalmic Plast Reconstr Surg. 2017; 33: 440-445
        • Rohrich R.J.
        • Ghavami A.
        Rhinoplasty for Middle Eastern noses.
        Plast Reconstr Surg. 2009; 123: 1343-1354
        • Ghorbani J.
        • et al.
        Structural characteristics of the Iranians nose: an anatomical analysis.
        Iran J Otorhinolaryngol. 2020; 32: 295-301
        • Rufer F.
        • Schroder A.
        • Erb C.
        White-to-white corneal diameter: normal values in healthy humans obtained with the Orbscan II topography system.
        Cornea. 2005; 24: 259-261
        • Goldberg R.A.
        • Lew H.
        Cosmetic outcome of posterior approach ptosis surgery (an American Ophthalmological Society thesis).
        Trans Am Ophthalmol Soc. 2011; 109: 157-167
        • Young S.M.
        • et al.
        Lowering of the high eyelid crease in revision upper eyelid surgery.
        Aesthetic Plast Surg. 2019; 43: 139-146
        • Lorden D.S.
        • et al.
        What is in a name? It is time to retire the term "Asian Blepharoplasty".
        Ophthalmic Plast Reconstr Surg. 2021; 37: 290-293
        • Rajabi M.T.
        • et al.
        A comparison of lower eyelid retraction in normal individuals with positive versus negative orbital vector.
        Middle East Afr J Ophthalmol. 2020; 27: 22-27
        • Kelley R.
        • et al.
        Irangeles: Iranians in Los Angeles. xiv. University of California Press, Berkeley1993: 396
        • Mehrjoo Z.
        • et al.
        Distinct genetic variation and heterogeneity of the Iranian population.
        PLoS Genet. 2019; 15e1008385
        • Bozorgmehr M.
        Internal ethnicity: Iranians in Los Angeles.
        Sociol Perspect. 1997; 40: 387-408