|Year : 2017 | Volume
| Issue : 1 | Page : 23-30
Ophthalmology national normative database series (3): Normal ranges of interorbital anthropometric values in healthy sudanese adults
Hajir Siraj1, Mahgoub Saleem2
1 Department of Ophthalmology, Medical Specializations Board, Al-Neelain University, Khartoum, Sudan
2 Department of Ophthalmology, Faculty of Medicine, Al-Neelain University, Khartoum, Sudan
|Date of Web Publication||8-May-2017|
Department of Ophthalmology, Faculty of Medicine, Al-Neelain University, P. O. Box. 10139, Khartoum 11111
Background: The face is the most distinctive part of the human body. Of all areas on the face, the bilateral orbital regions which are located in the upper half of the face act as a strong influence in the perception of facial attractiveness, esthetic criteria, and “ideal” features of any certain nation. This fact increases the needs for interorbital anthropometry or interocular distances (IODs) which refers to the measurements of the human far interpupillary distance (FIPD), near interpupillary distance (NIPD), outer canthal distance (OCD), and inner canthal distance (ICD) among individuals of different age, sex, and ethnicity.
Objective: To assess the normal ranges of interorbital anthropometric values among adult healthy Sudanese population and to define the effects of age, gender, and tribal ethnicity on interorbital anthropometry.
Materials and Methods: Systematic interorbital anthropometric measurements were done in 920 Sudanese adults aged 20–85 years. Parameters included were FIPD, NIPD, OCD, and ICD across age, sex, and tribal ethnic perspective of the study subjects. Comparisons were made between their gender, age, and tribal ethnicity using the Chi-square test.
Results: The study included 565 female (61.4%) and 355 male (38.6%) subjects with mean age of 48 ± 20 (range 20–85) years. Significant age, gender, and ethnical dimorphism were noted in the following parameters. OCD (male: 92.23 mm; female: 90.79 mm), FIPD (male: 63.20 mm; female: 61.57 mm), NIPD (male: 59.34 mm; female: 57.73 mm), and ICD (male: 34.30 mm; female: 33.00 mm).
Conclusion: Significant interorbital measurement differences were found between Sudanese males and females in different age and ethnic groups. The present study suggests that age, gender, and ethnicity should be considered in Sudanese esthetic criteria and “ideal” features in any cosmetic or reconstructive orbital surgery. To individualize the treatment planning and diagnosis, it is important for the surgeons to have knowledge of these local Sudanese interorbital norms.
Keywords: Anthropometric, esthetic criteria, far interpupillary distance, inner canthal distance, interorbital measurements, near interpupillary distance, outer canthal distance
|How to cite this article:|
Siraj H, Saleem M. Ophthalmology national normative database series (3): Normal ranges of interorbital anthropometric values in healthy sudanese adults. Albasar Int J Ophthalmol 2017;4:23-30
|How to cite this URL:|
Siraj H, Saleem M. Ophthalmology national normative database series (3): Normal ranges of interorbital anthropometric values in healthy sudanese adults. Albasar Int J Ophthalmol [serial online] 2017 [cited 2017 Oct 20];4:23-30. Available from: http://www.bijojournal.org/text.asp?2017/4/1/23/205802
| Overview|| |
The study of interorbital anthropometric values in healthy Sudanese adults will provide various interorbital biometric data which is very important to ophthalmologists, optometrists, pediatricians, maxillofacial surgeons and dentists. This will help in formulating successful different cranial and orbital facial reconstructive and cosmetic surgeries; as interorbital distances may be altered in congenital and posttraumatic deformities.,, Furthermore, these values are useful in the manufacture of spectacle frames and lenses and in the diagnosis and management of esotropia.,, In addition, they are important in the design of stereoscopic displaying devices and the production of stereoscopic content. Dentists use this as the predictor of maxillary central incisor width and selection of artificial teeth in edentulous subjects.
Sudan is known for its different ethnic groups that contain different racial origins. This diversion makes our knowledge about the Sudanese norm's instantly of variable issues, the answer of which highlights our needs of hospital- and community-based ophthalmic norm's studies.
| Introduction|| |
In biological investigational comparative studies, we need to analyze the forms of the organs by recording external geometric locations of certain “landmark points” to maintain accurate measurements between these points in different planes. These measurements obtain the anatomical and scientific names according to the studied organs; giving the concept of the morphometric and anthropometric studies of human beings.
Although the term “anthropometry” as refers to the measurements of the human individuals to note the physical variation was dated back to the 17th century when it appeared in the “short manual Anthropometria” by Johann Sigismund Elsholtz (1623–1688), anthropologists and artists identify human basic morphological characteristics by studying human body measurements in the ancient Egyptian, Greek, and Roman era.,
The face is the most distinctive part of the human body, with the bilateral orbital regions being located in the upper half of the face and act as a strong influence in the perception of facial attractiveness, youthfulness and health, esthetic criteria, and “ideal” features of any nation. This fact increases the needs for interorbital anthropometry which refers to the measurements of the human far interpupillary distance (FIPD), near interpupillary distance (NIPD), outer canthal distance (OCD), and inner canthal distance (ICD). Among these parameters, IPD is the best indicator of the distance between the centers of the globes.
There are significant differences in ocular and orbital morphometry among individuals of different age, sex, and ethnicity.,,,,,
Standard database regarding interorbital region is available for other ethnic groups in other countries. Since there is no data available in the literature, specifically for Sudanese adults, the present study was carried out to determine the normal average values for Sudanese adult population related to age, gender, and ethnicity.
IPD has been defined by various authors as the distance between the centers of the pupils  or the distance between the temporal limbus of one eye and the nasal limbus of the other eye. If this is measured for distant vision, it is called FIPD and if this is measured for near vision, it is called NIPD. OCD or ICD is the distance between the two lateral canthi with the subject looking straight ahead, whereas the ICD is the distance between the two medial acanthi with the subject looking straight ahead [Figure 1]., These interorbital distances can be measured by different ways and calipers such as rulers, digital positive displacement (PD)-meter [Figure 2], sliding caliper [Vernier Caliper; [Figure 3].
|Figure 1: Interorbital or interocular distances, IOD: Interocular distance, OCD: Outer canthal distance, ICD: Inner canthal distance, IPD: Interpupillary distance |
Click here to view
|Figure 2: Digital positive displacement meter: Shin Nippon PD Meter (Product Code IDIPD82)|
Click here to view
|Figure 3: Sliding caliper (Vernier Caliper): Neiko® 01407A electronic digital caliper with extra-large LCD Screen, 0–6-inches, standard, and metric|
Click here to view
| Materials and Methods|| |
This is a cross-sectional descriptive multi-center hospital-based study carried out for 5 months from January 2015 to May 2015 in a constant pattern of 3 days per week. It was conducted on volunteer Sudanese subjects; aged 20–85 years who were randomly selected from the eye clinics at Makkah Eye Complex, Faculty of Optometry and Visual Science of Al-Neelain University, Khartoum Eye Teaching Hospital and Al-Walidain Omdurman Eye Hospital; which are distributed over different metropolitan boroughs of Khartoum. Cases with craniofacial or orbital deformities, eye deviation, media opacity, history of trauma and facial or orbital fractures, history of ocular surgery, thyroid eye disease, or any ophthalmic disease that interfered with the measurement of OCD, IPD, and ICD were excluded from the study. Of 920 consecutive adult Sudanese participants, 565 (61.4%) females and 355 (38.6%) males [Figure 4] were studied. All participants underwent routine ophthalmic examination and systematic interorbital anthropometric measurements by digital PD-meter for IPDs, and OCD and ICD were measured directly by sliding caliper [Figure 3]. The data on the effect of age, gender, and tribal ethnicity on these interorbital anthropometric measurements were analyzed IBM SPSS Inc. PASW Statistics for Windows, Version 18.0; 2009. Chicago: SPSS Inc.
The study population were categorized by age into young adults (aged 20–39 years), middle-aged adults (aged 40–64 years), and older adults (aged above 65 years).
The whole subjects were classified into 5 different ethnic and racial groups and sub-groups according to “The Current Sudan Tribal composition” as follows:,,,,,,,,,,
The Arab origin groups
- Ga'alin groups:
Gaalin, Shaygia, Rubatab, Mirafab, Batahin, Bedayria, Gumoyia, Gemie, and Geme'aab
- Guhayna groups:
Kawahla, Kinaniah, Salahalbia, Gaafrah, Arakia, Halaween, Shokriah, Kababeesh, Jabriah, Misayriah, Gowamaha, Hasaniah, and Taaysha
Ashraf, Rikabia, Masalamya, Rashaida, Konooz, Hamran, Hawawer, Kenana, and Magharba.
The African origin groups
- The nonArab races of Darfur:
Fur, Bedayat, Kura'an, Zaghawa, Tama, Mido, Berti, Tungur, Dagu, Begu, Burghad, Mima, Mararit, Fallata, Masaleet, Erenga, Mun, Hadahid, Fertit, Tungur, and OmbaRaru
- Nubian tribes in Southern Kordofan
- Mapan tribes in Southern Blue Nile
- Angassana tribes in Southern Blue Nile
- Southern Nilotic tribes
- Western African group: (Hawsah, Brgaw, Falata, and Barnu).
The Nubian groups in the far North
Danagla, Mahas, and Halfaween.
The Bejja groups
Hadandawa, A'Marar, Beshare'een, BaneAmir, and Halnga.
Immigrants; Coptic, Mawaleeds, Ethiopians, Somalia's, Greece, etc.
Differences between the mean anthropometrical values of the measurements were tested using the Chi-square test with significance level set at P< 0.05.
Ethical considerations were cleared from Makkah Research Center and letters to the above hospitals. Verbal and written consent were taken from every participant after explaining to him/her that he/she was going to be enrolled in the study. Procedure was explained and confidentiality of information taken was ensured.
| Results|| |
In total, 920 individuals were studied. Of these, 565 (61.4%) subjects were females and 355 (38.6%) were males [Table 1] and [Figure 4]. The mean age of the study group was 47.84 ± 19.97 years (range: 20–85 years); 355 (38.6%) subjects were young adults of 20–39 years of age; 315 (34.2%) subjects were middle-aged adults of 40–64 years of age; and 250 (27.2%) subjects were old-aged adults of 65–85 years of age [Table 2].
The Arab origin groups represented 68.5% (n = 630) of the study population distributed as follows: (1) 305 (33.15%) subjects belonged to Ga'alin groups; (2) 295 (32.01%) belonged to Guyana groups; and (3) 30 (3.3%) belonged to other Arab groups. The African origin groups represented 17.9% (n = 165) of the study population distributed as follows: 50 (5.4%) to non-Arab races of Darfur; 50 (5.4%) to Nubian tribes in Southern Kordofan; and 65 (7.1%) to Western African groups. The Nubian groups in the far North represented 12% (n = 110) of the study population. Bejja groups represented 1.6% (n = 15) of the study population [Table 3].
The study population belonged to 36 tribes within the ethnic groups. Ga'alian constituted 21.2% (n = 195); Shaygia to 7.6% (n = 70); Danagla to 7.1% (n = 65); Gowamaha to 6.5% (n = 60); each of Nuba, Salahabia, and Misayriah 5.4% (n = 50); each of Mahas and Hawsa 3.8% (n = 35); each of Kawahla and Brgaw 3.3% (n = 30); each of Hasaniah and Fur 2.7% (n = 25); Habaniah 2.2% (n = 20); each of Bane-Amir, Rezigat, and Taaysha 1.6% (n = 15); each of Masaleet, Hawazma, Batahin, Khoalda, Daju, Bane-Halba, Bedayria, and Aglia 1.1% (n = 10); and each of Awamra, Kababeesh, Halfaween, Aesilat, Magharba, Halaween, Zaghawa, Hawawer, Rubatab, Gumoyia, and Tama 0.5% (n = 5) [Table 4].
The mean values and standard deviation of interorbital distance measurements of males and females are shown in [Table 5]. The mean anthropometrical values of the interorbital distance measurements were compared between the two genders using the Chi-square test. The average OCD for males and females were 92.23 ± 5.62 mm and 90.79 ± 4.57 mm, respectively. The average FIPD for males and females were 63.24 ± 3.33 mm and 61.57 ± 2.99 mm, respectively, and the NIPD for males and females were 59.34 ± 3.22 mm and 57.73 ± 3.01 mm, respectively. The average ICD for males and females were 34.30 ± 2.63 mm and 33.00 ± 2.72 mm, respectively. There was a statistically significant difference in all the measurements (P < 0.05) between the males and the females.
|Table 5: Comparison of outer canthal distance, far interpupillary distance, near interpupillary distance, and inner canthal distance according to gender|
Click here to view
The mean values and standard deviation of interorbital distance measurements of different age groups are shown in [Table 6]. The mean anthropometrical values of the interorbital distance measurements were compared between the different age groups using the Chi-square test. The average OCD were 93.23 ± 4.24 mm, 91.22 ± 5.62 mm, and 88.82 ± 4.15 mm; FIPD were 62.02 ± 3.34 mm, 62.48 ± 3.37 mm, and 62.11 ± 2.83 mm; NIPD were 58.23 ± 3.15 mm, 58.55 ± 3.51 mm, and 58.25 ± 2.79 mm; ICD were 33.59 ± 2.52 mm, 33.33 ± 2.84, and 33.61 ± 2.97 mm for young adults, middle-aged adults, and old-aged adults, respectively. There was a statistically significant difference in all the measurements (P < 0.05) between young adults, middle-aged adults, and old-aged adults.
|Table 6: Comparison of outer canthal distance, far interpupillary distance, near interpupillary, and inner canthal distance according to age groups|
Click here to view
The mean values of interorbital distance measurements of different ethnic groups are shown in [Table 7] and were compared using the Chi-square test. There was a significant difference in all the measurements (P < 0.05) between different ethnicities. Nearly, all the measurements were greater in the males compared with the females of the same ethnic groups. Males from Bijja groups have the largest FIPD (65.0 mm), NIPD (60.5 mm), and ICD (35.6 mm), while their females have the smallest OCD (88.9 mm), FIPD (61.0 mm), NIPD (57.1 mm), and ICD (31.9 mm) compared with other ethnic groups. Males from non-Arab races of Darfur have the largest OCD (93.9 mm). The values are compared between the males and between the females of different ethnic groups [Figure 5].
|Table 7: Comparison of outer canthal distance, far interpupillary distance, near interpupillary, and inner canthal distance according to ethnic groups|
Click here to view
|Figure 5: Differences of average gender intraorbital distances (outer canthal distance, inner canthal distance, and interpupillary distance)|
Click here to view
The mean values of interorbital distance measurements of different tribes within the ethnic groups are shown in [Table 8].
|Table 8: Comparison of outer canthal distance, far interpupillary distance, near interpupillary, and inner canthal distance in mm according to tribes|
Click here to view
| Discussion|| |
National standard database regarding interorbital anthropometric values is mandatory for any nation, especially if it is of a widely diverse multiethnic composition such as Sudan. Due to scarcity of these types of studies in the literature, this current work was carried out to determine the normal average interorbital anthropometric values  for Sudanese Adults related to gender, age, and tribal ethnicity. In the existing study, the average four interorbital values or distances (IOD), which include the OCD, ICD, FIPD, and NIPD  of Sudanese adult males and females of different ages and ethnicities were evaluated, and the data were compared with other international racial and ethnic groups.
In this study, significant age, gender, and ethnical dimorphism were noted in these IOD values: OCD (male: 92.23 mm; female: 90.79 mm), ICD (male: 34.30 mm; female: 33.00 mm), FIPD (male: 63.20 mm; female: 61.57 mm), and NIPD (male: 59.34 mm; female: 57.73 mm).
Males in all ethnic groups had bigger IOD values than females by 1.6% in average [Table 5] and [Figure 1]. This results trigger on the fact that males have bigger anatomical features and statues, as compared to their national female communities. Scientifically, this can be well explained by the normal biological feminine and masculine differences of facial and body features on the bases of sexual dimorphism in anthropometric measurements.,,
Orbitofacial anthropometrics values have become an important tool used for the diagnosis of many genetic dysmorphic syndromes and in reconstructive surgery. OCD, ICD, and IPD are commonly used in the assessment of telecanthus  and hypertelorism. Kulkarni et al. have suggested that a clear distinction should be made between these measurements in the assessment of hypertelorism. As the ICD and OCD measurements are usually affected by the surrounding soft tissue, the ICD may be increased due to broad nasal bridge. Hence, they suggested that IPD is an additional accurate measure for hypertelorism.
There was a statistically significant difference in OCD, FIPD, NIPD, and ICD between the males and females (P < 0.05), between the different age groups, and between various ethnicities of Sudanese adults [Table 5] and [Figure 5]. Variations and similarities were detected in certain key parameters between the Sudanese adult population and other nations.
The majority of our study population (65.5%) was from the Arab origin groups (Ga'alin constituting 33.15% and Guhayna constituting 32.05%). The limitation of this study was that almost two-thirds was from the aforementioned Arab origin groups, and little above one-third (34.7%) was from the other tribes. This made the study represent mainly; the Sudanese Arab Origin groups; rather than the whole mixed population.
In [Table 6], there was statistically significant variations (P < 0.05) of OCD according to age; there were differences between younger adult age group (20–39 years) and middle and old age groups (40–64 years and 65–85 years) in the rate of OCD 93.23±4.24 (younger adul91.22±5.62 (Middle age) 88.82±4.15(older age). There were 2.16% and 4.73% differences more in younger than middle and old age groups, respectively. These age variations are more than the Indian Chhattisgarh region study who recorded only 0.43% increase of OCD between young and middle-aged populations. This is most probable due to natural evolutional aging facial rhytids.
The largest OCD between adult Sudanese was found in non-Arab races of Darfur (93.90 mm) followed by Bejja group (93.40 mm) and the smallest for the Nubian group in far North followed by Nubians in South Kordofan and Guhayna groups [
[Table 7]. There was no clear explanation for this; a part from possible intermarries between some Guhayna in South Kordofan and their neighbors; the Nubians of South Kordofan. The IPD gender variations in Bejja group (4.8%) were recorded to be very wide as compared to other Sudanese tribes; Bijja male FIPD is larger than their female fellows by 4.8%, which is double than in other Sudanese tribes (2.2%). This Bijja's result is exactly the same as in Turkish; 4.8%, and North American Caucasian; 4.8%. These above results are in contrary with the bigger difference of Ijaws of Nigeria; 5.1% and South Indian; 6.2%. Koreans had an odd reverse situation where the IPD in females (63.5%) is bigger than their male (59.9) fellows.
Although males from non-Arab races of Darfur of African origin group have the largest OCD between Sudanese tribes (93.9 mm), still they are lower than the Western Africans. The difference in the mean values between various ethnic groups is small; this may be due to inter-racial marriage. The Nubian tribes in Southern Kordofan and the Nubian groups in far North have very close values, which can be explained the hypothesis of the immigration of the Nubian in Southern Kordofan from the Upper Nubia in the far North after the fall of The Kingdom of Kush in Upper Nubia.
In the current study, the average OCD is almost in the range of other nations; being 92.2 mm in Sudanese males and 90.9 mm in Sudanese females. This differed significantly from, and were consistently lower than, their reported measurements of 103.90 mm OCD in males and 93.3 mm in females. The Thai people from Southern Thailand ethnic groups reported the lowest IOD measurements; OCD (88.10 for males; 85.80 for females), ICD (30.60 in males; 32.60 in females), and IPD (61.30 in males; 59.50 in females).
| Conclusions|| |
The outcome of this study indicates that there is a statistically significant racial, gender, and age differences exist for IOD, so these factors' background should be considered when evaluating these parameters. Significant age, gender, and ethnical dimorphism were noted in all IOD values: OCD (male: 92.23 mm; female: 90.79 mm), ICD (male: 34.30 mm; female: 33.00 mm), FIPD (male: 63.20 mm; female: 61.57 mm), and NIPD (male: 59.34 mm; female: 57.73 mm). Data showed variations and similarities (racial and sexual) with other populations. It is important for the surgeons to have knowledge of local norms during facial analysis to evaluate and modify the disproportionate features without disturbing the ethnical features. The results of this study will be of immense use in surgical procedures such as ocular prosthetics, blepharoplasty, and in forensic science to trace missing individuals by applying facial reconstruction techniques, dentistry, genetics, and anthropological studies.
More studies are needed on other ocular anthropometric measurements to set a normative database of Sudanese population in both adults and children. Indirect anthropometry using standardized photography combined with computer analysis is recommended to perform full anthropometric analysis of the eyes.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Chan W, Madge SN, Senaratne T, Senanayake S, Edussuriya K, Selva D, et al.
Exophthalmometric values and their biometric correlates: The Kandy Eye Study. Clin Experiment Ophthalmol 2009;37:496-502.
Gupta VP, Sodhi PK, Pandey RM. Normal values for inner intercanthal, interpupillary, and outer intercanthal distances in the Indian population. Int J Clin Pract 2003;57:25-9.
Fesharaki H, Rezaei L, Farrahi F, Banihashem T, Jahanbkhshi A. Normal interpupillary distance values in an Iranian population. J Ophthalmic Vis Res 2012;7:231-4. [Full text]
Elkington AR, Frank HJ. Clinical Optics. 3rd
ed. Wiley-Blackwell; 1999. p. 110-1, 276.
Abdullah MA. Inner canthal distance and geometric progression as a predictor of maxillary central incisor width. J Prosthet Dent 2002;88:16-20.
Fadlalla M, Saleem M. Character of the Normal Anterior Chamber Angle in Sudanese Adults; 2008-2009; Clinical MD Thesis Submitted for SMSB; Council of Ophthalmology; 2009.
Tie Y, Guan L. Automatic landmark point detection and tracking for human facial expressions. EURASIP J Image Video Process 2013;2013:8.
Richtsmeier JT, Deleon VB, Lele SR. The promise of geometric morphometrics. Yearb Phys Anthropol 2002;45:63-91.
Utkualp N, Ercan I. Anthropometric measurements usage in medical sciences. Biomed Res Int 2015;2015:404261.
Ulijaszek SJ, Mascie-Taylor CG. Anthropometry: The Individual and the Population. Cambridge, UK: Cambridge University Press; 2005.
Gosavi SN, Jadhav SD, Zambre BR. A study of orbital morphometry in Indian dry skulls. Asian Journal of Biomedical and Pharmaceutical Sciences; 2014;04 (29):23-5.
Pryor HB. Objective measurement of interpupillary distance. Pediatrics 1969;44:973-7.
Shah K, Sambav S, Jethani J, Gupta A, Bidasaria N. An assessment of the interpupillary distance, the inner and outer intercanthal distances in the normal Indian population from early neonatal period up to over 70 years of age: A study of 3500 subjects. BJ Kines: National Journal of Basic & Applied Sciences. 2014;6(1):17-25. [doi:10.6.4/article-4].
Osuobeni EP, al-Gharni SS. Ocular and facial anthropometry of young adult males of Arab origin. Optom Vis Sci 1994;71:33-7.
Albashir SI, Saleem M. Normal range values of ocular axial length in adult Sudanese population. Albasar Int J Ophthalmol 2015;3:31-8. [Full text]
Report from the Embassy of the Republic of the Sudan Washington D.C.; 2210 Massachusetts Ave; Washington DC, (2008), Embassy Press© Copyright.sudanembacy.org; 2014.
MacMichael HM. A History of the Sudan and Some Account of the People Who Proceeded them and the Inhabiting. Darfur: Frank Cass and CO. Ltd., London WCI, Cambridge University Press and Thomas Nelson Ltd.; 1967. [1-2, 2d Impression 1967].
MacMichael HM. The Tribes of Northern and Central Kordofan, Arabic Translation by Abdelmagid S. 1st
ed. Omdurman, Sudan: Copyright of Abdel-Karim Mirghani Cultural Centre; 2012.
Hasan FY. The Arabs and the Sudan; From the Seventh to the Early Sixteenth Century. 3rd
ed. Khartoum University Press; Publishing and Distribution Book's House; Sudan; 1973.
Al-Sideq H, Mahgoub HM. History of Arabs and roots. Genealogy and History of Hashemite and Arabic Bedouin. Vol. 2. Sudan Coining Press Ltd.; 1798-1918.
Shogair N. Geography and History of Sudan; Dar Athagafa. 2nd
ed. Beruit: 'Dar Alnashr Publishing'; 1972.
A'rkal AJ. Transilated by Osman A, Abdraheem. Origin of Funj; Sudan Notes and Records (1932-1946). 1st
ed. Azza Publishing and Distribution House; 2013.
Ishag I. Migration of Helaleen from Arabic Island to South Africa and Sudan. 1st
ed. Khartoum, Sudan: Sudan Culture and King Faisal Research and Study Centre; 1996.
Albasheer IA. All of You. 1st
ed., Sec. 1. Sudan: Dar Azza Press, Study in Sudan Ethnicity, Husynea and Haseenya Ashraf, Azza Publishing and Distribution House; 2004.
Ahmad OB, Boschi-Pinto C, Lopez LD, Murray CJ, Lozano R, Inoue M. Age Standardization of Rates: A New Who Standard. GPE Discussion Paper Series: No. 31; EIP/GPE/EBD. World Health Organization; 2001.
Etezad-Razavi M, Jalalifar S. Correlation between interpupillary and inner-outer intercanthal distances in individuals younger than 20. J Ophthalmic Vis Res 2008;3:16-22.
Barretto RL, Mathog RH. Orbital measurement in black and white populations. Laryngoscope 1999;109(7 Pt 1):1051-4.
Albashir SI, Saleem M. Normal range values of ocular axial length in adult Sudanese population. Albasar Int J Ophthalmol 2015;3:31-8. [Full text]
Samal A, Subramani V, Marx D. An analysis of sexual dimorphism in the human face. J Vis Commun Image Represent 2007;18:453-63.
Bruce V, Burton AM, Hanna E, Healey P, Mason O, Coombes A, et al.
Sex discrimination: How do we tell the difference between male and female faces? Perception 1993;22:131-52.
Agrawal J, Yogesh AS, Shukla CK, Banerjee C, Chandrakar AK. Orbitofacial anthropometric assessment of inter-canthal and outercanthal distance measurement in Chhattisgarh region. Biomed Res 2013;24:365-9.
Kulkarni ML, Rajendran NK, Sangam DK. Inner canthal, outer canthal and inter pupillary distance in newborns. Indian Pediatr 1992;29:759-63.
Kaur M, Garg RK, Singla S. Analysis of facial soft tissue changes with aging and their effects on facial morphology: A forensic perspective. Egypt J Forensic Sci 2015;5:41-72.
Bozkir MG, Karakas P, Oguz O. Measurements of soft tissue orbits in Turkish young adults. Surg Radiol Anat 2003;25:54-7.
Oztürk F, Yavas G, Inan UU. Normal periocular anthropometric measurements in the Turkish population. Ophthalmic Epidemiol 2006;13:145-9.
Farkas LG, Katic MJ, Forrest CR, Alt KW, Bagic I, Baltadjiev G, et al.
International anthropometric study of facial morphology in various ethnic groups/races. J Craniofac Surg 2005;16:615-46.
Oladipo GS, Okoh PD, Hart JS. Anthropometric study of ocular dimensions in adult Ijaws of Nigeria. Res J Med Med Sci 2010;5:121-4.
Vasanthakumar P, Kumar P, Rao M. Anthropometric analysis of palpebral fissure dimensions and its position in South Indian ethnic adults. Oman Med J 2013;28:26-32.
Kim CJ, Ham KS, Kim Y, Cho YJ. A facial anthropometric study on the Korean youths. J Korean Soc Plast Reconstr Surg 1998;15:427.
Welsby DA. Welsby DA. The Kingdom of Kush: The Napatan and Meroitic Empires. Marcus Wiener; 1999. p. 240.
Anthropometry of eyelid and orbit in four southern Thailand ethnic groups. J Med Assoc Thai 2011;94:193-9.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8]