Normal values of eye position in the Chinese population of Hong Kong

Usefulness of automated image analysis for recognition of the fragile X syndrome gestalt in Congolese subjects

BACKGROUND

Computer-aided software such as the facial image diagnostic aid (FIDA) and Face2Gene has been developed to perform pattern recognition of facial features with promising clinical results. The aim of this pilot study was to test Face2Gene's recognition performance on Bantu Congolese subjects with Fragile X syndrome (FXS) as compared to Congolese subjects with intellectual disability but without FXS (non-FXS).

METHOD

Frontal facial photograph from 156 participants (14 patients with FXS and 142 controls) predominantly young-adults to adults, median age 18.9 age range 4-39yo, were uploaded. Automated face analysis was conducted by using the technology used in proprietary software tools called Face2Gene CLINIC and Face2Gene RESEARCH (version 17.6.2). To estimate the statistical power of the Face2Gene technology in distinguishing affected individuals from controls, a cross validation scheme was used.

RESULTS

The similarity seen in the upper facial region (of males and females) is greater than the similarity seen in other parts of the face. Binary comparison of subjects with FXS versus non-FXS and subjects with FXS versus subjects with Down syndrome reveal an area under the curve values of 0.955 (p = 0.002) and 0.986 (p = 0.003).

CONCLUSION

The Face2Gene algorithm is separating well between FXS and Non-FXS subjects.

Prediction of exophthalmos by body mass index for craniofacial reconstruction: consequences for cold cases

It is inconvenient for a forensic practitioner to gather population-specific data before performing a facial reconstruction. The inconvenience may defeat the point of creating the reconstruction. The objective of this study was to evaluate a non-population-dependent method of determining exophthalmos. The protrusion of the eyeball is known to vary with the contents of the orbital cavity based on bony orbital resorption or increased or decreased fat contents, as well as according to relative eyeball size. Of use are available statistics on body mass index, and this is discussed within the context of eyeball protrusion. A weak positive correlation (0.3263) between the body mass index of the country where the study originated, and the degree of exophthalmos was found. The results suggest that eyeball protrusion rates can be established according to body mass index, and this framework may be more useful considering conventional police practices.

Expanding the Classic Facial Canons: Quantifying Intercanthal Distance in a Diverse Patient Population

Background:

The intercanthal distance (ICD) is central to our perception of facial proportions, and it varies according to gender and ethnicity. Current standardized reference values do not reflect the diversity among patients. Therefore, the authors sought to provide an evidence-based and gender/ethnicity-specific reference when evaluating patients’ ICD.

Methods:

As per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic search of PubMed, Medline, and Embase was carried out for studies reporting on the ICD. Demographics, study characteristics, and ICDs were extracted from included studies. ICD values were then pooled for each ethnicity and stratified by gender. The difference between men and women, and that across ethnicities and measurement types were compared by means of independent sample t-test and one-way ANOVA (SPSS v.24).

Results:

A total of 67 studies accounting for 22,638 patients and 118 ethnic cohorts were included in this pooled analysis. The most reported ethnicities were Middle Eastern (n = 6629) and Asian (n = 5473). ICD values (mm) in decreasing order were: African 38.5 ± 3.2, Asian 36.4 ± 1.6, Southeast Asian 32.8 ± 2.0, Hispanic 32.3 ± 2.0, White 31.4 ± 2.5, and Middle Eastern 31.2 ± 1.5. A statistically significant difference (P < 0.05) existed between all ethnic cohorts, between genders among most cohorts, and between most values stratified by measurement type.

Conclusions:

Our standards of craniofacial anthropometry must evolve from the neoclassical canons using White values as references. The values provided in this review can aid surgeons in appreciating the gender- and ethnic-specific differences in the ICD of their patients.

Agreement and inter-session repeatability of manual and automatic interpupillary distance measurements

BACKGROUND

Interpupillary distance (IPD) is important in developmental anatomy, genetics, design of optical instrumentation, ocular diagnostics, and optical prescribing. IPD frequently is measured on different days, and by either automatic pupillometers (physiological measurement) or manual ruler (anatomical measurement). Therefore, there is importance in the agreement and inter-session repeatability of manual and automatic IPD measurements.

METHODS

Monocular distance from the bridge of the nose and binocular distance and near binocular IPD were randomly measured, using a millimeter ruler and the Essilor Pupillon pupillometer. Gender effects were assessed using Wilcoxon and Mann-Whitney tests, respectively. Agreement was assessed using Spearman correlation and Bland-Altman (B&A) plots. Thirty additional participants were tested within 1-2 weeks to determine the inter-session repeatability.

RESULTS

The agreement study included 199 participants (mean age: 24.1 ± 5.0 range: 19-53, 58 male, 141 female) and the repeatability sub- study included 30 (mean age: 27.9 ± 4.5, range: 23-39, 6 male, 24 female). Males and females significantly differed in age (<2 year mean difference (md)) and IPD (monocular md: < 1 mm, binocular md: < 2 mm). Manual vs. automatic measurements were significantly different for all conditions (md: <1 mm for all) except for distance left eye male PD. There was no significant difference between the session for both methods.

CONCLUSIONS

Binocular and monocular manual and automatic measurements were significantly different statistically, but not clinically. Distance binocular IPD was approximately 3 mm wider than near IPD. Male binocular IPD was approximately 2 mm wider than the female IPD. Both methods had good inter-session repeatability.

Normal Ocular Protrusion Values in South Indian Population and Effect of Age, Gender and Refractive Status on Ocular Protrusion

Aim

To determine the absolute and relative ocular protrusion values in normal south Indian population, and its relation to age, gender and type of refractive error.

Methods

A total of 387 subjects aged 7–70 years were included in this study. Both right and left absolute ocular protrusion values were measured by a single physician using Luedde exophthalmometer in primary gaze. Right eye ocular protrusion data were used for reporting the absolute ocular protrusion values, and difference between right and left eye absolute ocular protrusion values of the same individual was used to report the relative ocular protrusion values. Subject age was grouped as decades. Measurement values were evaluated by descriptive and inferential statistics.

Results

The mean absolute ocular protrusion of right eye was 14.67 ± 1.70 mm and left eye was 14.32 ± 1.75 mm. The mean right absolute ocular protrusion values from 1st to 7th decade were 12.73 ± 1.21 mm, 14.8 ± 1.25 mm, 15.79 ± 1.31 mm, 15.77 ± 1.36 mm, 15.87 ± 1.28 mm, 15 ± 1.03 mm and 14.36 ± 0.88 mm respectively. One-way analysis of variance showed that there was a significant difference in the ocular protrusion among the age groups (p < 0.005). The mean relative ocular protrusion was 0.35 ± 0.64 mm. The type of refractive error (up to ±6.00D) has no significant effect on the absolute ocular protrusion values and showed a weak correlation between magnitude of myopia and hyperopia on absolute ocular protrusion. There was a statistically significant difference in absolute ocular protrusion among the female and male subjects.

Conclusion

Age and gender seems to significantly influence the absolute ocular protrusion and need to be considered for clinical evaluation of bilateral proptosis. The refractive error up to ±6.00D seems to have no significant effect on the absolute ocular protrusion.

Craniofacial Anthropometry of Healthy Turkish Young Adults: Outer Canthal, Inner Canthal, Palpebral Fissure, and Interpupillary Distances

ABSTRACT

This study aims to examine the values of the orbital region in Turkish young adults by the two-dimensional photogrammetry. Anthropometric measurements of the eye and eyelid-related parameters were taken from 100 female and 100 male volunteer Turkish young adults, ranging in age from 18 to 25 years. Endocanthion (en), exocanthion (ex), and pupil (p) were identified on the photograph and the distances between these points were measured with the ImageJ program. The average values of the en-en, ex-en (R), ex-en (L), p-p, and ex-ex were found as 32.92 ± 2.84, 32.48 ± 2.06, 32.22 ± 2.01, 65.32 ± 3.77, and 97.75 ± 5.09 mm, respectively. There were statistically significant differences between the genders in all parameters. Although there are many studies examining these parameters, comprehensive studies are needed in different populations and in many cases. In this study, we believe that the results obtained for Turkish young adults can be used as reference values.

Normative Exophthalmometry Measurements Vary Among Ethiopian Adults and the Major Ethiopian Ethnic Groups

PURPOSE

Periocular and orbital anthropometric values vary among races. No studies have established normative exophthalmometry values for Ethiopians or the many Ethiopian ethnic groups. This study established a set of normative anthropometric values for exophthalmometry, and further evaluated whether these measurements differed based on sex or ethnic group.

METHODS

A cross-sectional study was performed in the ophthalmology department at St. Paul's Hospital in Addis Ababa, Ethiopia. Two hundred ninety-six participants were recruited for the study. Sex, primary Ethiopian ethnic subgroup, and exophthalmometry measurements were recorded. Differences between ethnicities and sexes were evaluated using independent samples t test.

RESULTS

Average proptosis for the total cohort was 15.88 ± 2.49 mm, with 582 eyes measured. Females (15.87 ± 2.53, n = 286) and males (15.89 ± 2.49, n = 296) were not significantly different in their proptosis measurements. Within the 3 largest ethnic groups measured, Amhara (16.12 ± 2.67, n = 204), Oromo (15.43 ± 2.51, n = 172), and Gurage (16.23 ± 2.59, n = 98), the difference in proptosis measurement was significant between the Amhara and Oromo groups (p = 0.01), and the Oromo and Gurage groups (p = 0.01). The only ethnic group that was significantly different between sexes was Gurage, of which average female proptosis was 15.51 ± 2.74 (n = 54), while male proptosis was 17.13 ± 2.11 (n = 44) (p < 0.01).

CONCLUSIONS

Mean Ethiopian proptosis values vary across ethnicities, are similar to those measured in other African populations, but are lower than those established in African-American populations. This study provides an important resource that Ethiopian ophthalmologists can use when evaluating patients with suspected ophthalmic and orbital disease.

Exophthalmometry values in the Hong Kong Chinese adult population from a population-based study

This study aims to establish the range of exophthalmometry values (EV) in the adult Hong Kong (HK) Chinese population, its relationship with various anthropometric parameters, and to compare it with the EV in different ethnic groups.About 1485 adult HK Chinese were drawn from a random sample from the community-based FAMILY Cohort. Participants were interviewed, and comprehensive ophthalmological assessments were conducted. EV was measured using the Hertel's exophthalmometer.EV of both eyes from 630 male (42.4%) and 855 female (57.6%) participants, mean age 54 ± 17.2 and 52 ± 16 respectively were analyzed. The mean EV were found to be 15.3 ± 2.8 mm in the right eye, 15.2 ± 2.9 mm in the left eye for men and 14.4 ± 2.7 mm in the right eye, 14.3 ± 2.7 mm in the left eye for women. There were no differences in the EV between right and left eyes (P > .05). Men had significantly higher EV than women (P < .05) and age was found to be negatively correlated to EV (P < .05). Body height (r = 0.20), weight (r = 0.25), waist (r = 0.11), hip circumference (r = 0.15), body mass index (r = 0.17), interpupillary distance (r = 0.54), and axial length (AL) (r = 0.20) were all found to have statistically significant positive correlations with EV (P < .01). Spherical equivalent was found to have statistically significant negative correlation with EV (P < .01).Our study provides normative data on EV in the HK Chinese population. Height, weight, interpupillary distance, waist, hip circumference, and AL had positive correlations with EV. Spherical equivalent had negative correlation with EV. There was no significant difference in EV between the right and left eye. Age and gender had significant effect on EV.

Pupil dilation as an index of effort in cognitive control tasks: A review

Pupillometry research has experienced an enormous revival in the last two decades. Here we briefly review the surge of recent studies on task-evoked pupil dilation in the context of cognitive control tasks with the primary aim being to evaluate the feasibility of using pupil dilation as an index of effort exertion, rather than task demand or difficulty. Our review shows that across the three cognitive control domains of updating, switching, and inhibition, increases in task demands typically leads to increases in pupil dilation. Studies show a diverging pattern with respect to the relationship between pupil dilation and performance and we show how an effort account of pupil dilation can provide an explanation of these findings. We also discuss future directions to further corroborate this account in the context of recent theories on cognitive control and effort and their potential neurobiological substrates.

Masking the Close Eye Appearance in the East Asian Female Population: Infratemporal Hairline Reduction with Hair Grafting

Purpose

To investigate the effectiveness of hairline advancement in treating patients with perceived close-set eyes due to a wide infratemple area.

Materials and Methods

Infratemple area hairline advancement was performed in 19 patients with perceived close-set eyes caused by a wide infratemple area; all were women with a mean age of 29.4 years.

Results

The wide infratemple area was effectively narrowed in the frontal view in all patients. The mean reduction in the distance between the bilateral infratemple hairlines in the frontal view was 5.2 mm (range 3.9–6.3 mm). The appearance of close-set eyes was ameliorated, and patient satisfaction was high. No side effects, such as asymmetry or wound infection, were encountered.

Conclusion

Hairline advancement surgery appears to be a safe and effective means of treating patients with perceived close-set eyes due to a wide infratemple area.

Level of Evidence IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Exophthalmometry value distribution in healthy Lithuanian children and adolescents

Purpose

To determine absolute and relative ocular protrusion values for healthy Lithuanian children and adolescents and analyze the data according to the age, gender, weight, height, and outer orbital distance.

Methods

A total of 397 children and adolescents were included in this study. Measurements for the right and left eyes protrusions were done with Hertel exophthalmometer in healthy subjects aged from 5 to 18 years old. Height, weight, age and gender of subjects were recorded.

Results

The mean age for all children and adolescents was 11.5 ± 3.6 years. For all subjects, the mean (±SD) absolute ocular protrusion value of both eyes (OU) was 14.91 ± 1.68 mm. There was no significant difference in measurements between male and female subjects although female eye protrusion was higher. No individual had more than 2 mm of asymmetry between eyes. Mean exophthalmometric values for right eye were greater than the values of the left eye, and the mean relative protrusion for all participants was 0.2 mm. The mean distance between the lateral rims of the orbits was 98.7 ± 5.2 mm for all subjects. Proptosis measurements significantly correlated with the age, weight and height of children and adolescents and base measurements.

Conclusions

In the present study, we have established ocular proptosis values according to the age, gender, weight and height of healthy Lithuanian children and adolescents. The eye protrusion significantly correlated with the age, weight and height of subjects and the distance between the lateral rims of the orbits. The gender did not play significant role on the eye projection data. We believe that larger, well-design studies are necessary in future to assess the distribution of proptosis in healthy Lithuanian children and adolescents.

The Effect of Age, Gender, Refractive Status and Axial Length on the Measurements of Hertel Exophthalmometry

Purpose :

To evaluate the normal distribution of exophthalmometric values in Turkish adult population and the effect of age, gender, refractive status and axial length on globe position.

Methods :

One hundred and twenty-two males and 114 healthy females with age ranging from 18 to 87 years were included in the study. The study population was recruited from patients presenting to our institution for routine refractive examination. Hertel exophthalmometer was used to measure the degree of ocular protrusion. Effect of age, refractive error, interpupillary distance, and axial length on globe position was detected with linear regression analyses.

Results :

The mean Hertel exophthalmometric size was 15.7+2.6 mm (range; 11 to 21 mm). The mean value for males was 16.1±2.6 mm (range; 11 to 21 mm), and for females 15.5±2.6 mm (range; 11 to 20 mm). The mean distance between the lateral rims of the orbit was 102 + 5.1 mm (range; 88 to 111mm). The mean exophthalmometric values were not statistically different in males and females. Age and mean spherical equivalents were negatively correlated with exophthalmometric measurements. Axial length was positively correlated with exophthalmometric measurements.

Conclusion :

The exophthalmometric measurement of the eye is affected by the age, spherical equivalent and the axial length. Standard normative values of the Hertel exophthalmometric measurements should be reevaluated with larger samples.

Normal values of Hertel exophthalmometry in a Chinese Han population from Shenyang, Northeast China

Aims of this study were to determine the normal range of absolute and relative Hertel exophthalmometric values (EVs) in a Chinese Han population. This population-based cross-sectional study consisted of 2010 healthy Han Chinese (1051 females and 959 males) aged between 8-87 years living in Shenyang, Northeast China, including 515 children (aged 8-14 years), 517 teenagers (aged 15-19 years), 582 adults (aged 20-69 years) and 396 elderly (aged 70-87 years). A Hertel exophthalmometer was used by the same physician for the measurement of EV and inter-orbital distance (IOD). For the entire study population, the Hertel EVs ranged from 10 mm to 22 mm; the mean EVs for the left eye (OS) and right eye (OD) were 15.0 ± 1.9 mm and 15.0 ± 2.0 mm, respectively; the upper normal limits of the EVs (mean + 2 SD) for OS and OD were 18.8 mm and 19.0 mm, respectively; the mean relative EV was 0.20 ± 0.43 mm. Age, but not sex, had a significant effect on the EV. We concluded that our study provides normative ophthalmic data in a Chinese Han population. The normal EVs, asymmetry and IOD values have been established for clinical reference.

Horizontal eye position in thyroid eye disease: a retrospective comparison with normal individuals and changes after orbital decompression surgery

Objective

To compare horizontal eye positions between proptotic thyroid eye disease patients and normal individuals, and to examine positional changes after orbital decompression surgery in thyroid eye disease patients.

Methods

The present case-controlled and retrospective comparative study included 78 proptotic thyroid eye disease patients who underwent bilateral orbital decompression surgery [lateral orbital wall decompression (Group L), 47 patients; medial orbital wall decompression (Group M), 9 patients; and balanced orbital decompression (Group B), 22 patients] and 143 age-matched healthy volunteers as controls. The interpupillary distance was measured to determine horizontal eye positions before and 3 months after surgery in thyroid eye disease patients and was also examined in control eyes. Horizontal eye shifts were calculated by subtracting postoperative from preoperative interpupillary distances.

Results

Preoperative interpupillary distances in thyroid eye disease patients were significantly larger than in controls. The interpupillary distances were significantly decreased postoperatively in Groups M and B, but were significantly increased in Group L. The order of the magnitude of the horizontal shifts was Groups M>B>L.

Conclusions

Proptotic thyroid eye disease patients preoperatively showed laterally displaced eyes in comparison with controls. However, the eyes shifted medially after the medial orbital wall decompression and the balanced orbital decompression, although the former showed more shift. Medial orbital wall or balanced orbital decompression can be used to correct both lateral and anterior displacement of the eyes.

White-to-white corneal diameter: normal values in healthy Iranian population obtained with the Orbscan II

AIM

To determine the normative values of white-to-white corneal diameter with Orbscan II Topography System and to compare right and left eyes data in the normal young population.

METHODS

A total of 1001 healthy participants aged 18-45y participated in this observational cross-sectional study. The study population consisted of 616 female and 385 male subjects. The corneal diameter was measured with the Orbscan II. The differences between genders, between right and left eyes and age-related changes were evaluated. Statistical analyses were performed using Student's t-test.

RESULTS

The average white-to-white distance in our study population was recorded as 11.65±0.36 mm (median: 11.60 mm, mode: 11.70 mm, minimum: 10.50 mm and maximum: 13.60 mm). The white-to-white distance was 11.60±0.35 mm in males and 11.71±0.36 mm in females which was statistically different between genders (P<0.01). However, white-to-white distance was not statistically different between right and left eyes. In addition, this parameter decreased with increasing age. Considering 95% confidence interval, corneal diameter less than 10.93 mm and greater than 12.34 mm would be considered as microcornea and megalocornea, respectively based on this study population, using the Orbscan II topography.

CONCLUSION

Detailed description and analysis of corneal diameter with Orbscan demonstrate that the obtained average value of horizontal white-to-white is higher in male than female and decreases slightly with increasing age. Our data also suggests the cut off values for definition of microcornea and megalocornea, which can be employed with this population.

Influence of age on measured anatomical and physiological interpupillary distance (far and near), and near heterophoria, in Arab males

PURPOSE

To compare the effects of age and near phoria on interpupillary distance measured at far (FIPD) and near (NIPD) using the Viktorin's and pupillometer (PD-5) methods.

METHODS

Interpupillary distance (IPD) by Viktorin's method and the corneal reflex pupillometer (PD-5) method, as well as near heterophoria by the Saladin near point card, were each obtained on 133 randomly selected normal subjects aged 20-67 years. Comparison within and between techniques, influence of age on IPD, and near heterophoria were assessed.

RESULTS

The mean FIPD varied significantly from the NIPD (P < 0.001 for both methods). Overall, FIPD ranged from 56-73 mm, and NIPD ranged from 50-70 mm. For FIPDs of 55 mm, 63 mm, and 71 mm, the corresponding NIPDs were less by 3.9 mm, 4.4 mm, and 5.0 mm, respectively, which were measured by Viktorin's method, and 4.0 mm, 4.6 mm, and 5.2 mm, respectively, measured by the PD-5 method. Between methods, the limits of agreement were: -3.9 mm and 3.2 mm (P > 0.05) for FIPD, and -3.1 mm and 2.9 mm (P > 0.05) for NIPD. Both IPDs varied significantly across age groups (P < 0.0001). Post hoc analysis revealed a significant variation (P < 0.01 in both techniques) only in the comparison between age groups 16-25 years and 41-67 years. The mean difference was -2.2 mm (-4.0 mm to -0.3 mm) and -2.8 mm (-4.7 mm to -1.0 mm) for Viktorin's method for FIPD and NIPD, respectively. For PD-5, the corresponding values were -1.3 mm (-3.2 mm to 0.4 mm) and -1.7 mm (-4.1 to -0.5 mm). Also, the near phoria differed significantly (P < 0.0001) across age groups and correlated positively with age (r(2) = 0.27, P < 0.0001) and NIPD (r(2) > 0.04; P < 0.03, both techniques).

CONCLUSION

The difference between FIPD and NIPD (about 4.4 mm in Arab males) was observed independent of the technique used. The Viktorin's and the PD-5 methods of IPD assessment resulted in similar values, and therefore, could be interchangeably used. However, caution is advised in cases of high power refractive corrections as the difference could vary from -4 mm to +3 mm (FIPD) and -3 mm to +3 mm (NIPD). Both IPDs have demonstrated an increase until the patients are in their early 40s, and a slight decrease has been observed thereafter. Age and NIPD were significantly associated with heterophoria in our subjects.

Age, gender, corneal diameter, corneal curvature and central corneal thickness in Nigerians with normal intra ocular pressure

Purpose

To investigate the relationship between age, gender, corneal diameter, central corneal curvature, central corneal thickness (CCT) and intraocular pressure in Nigerians with normal intraocular pressure.

Methods

One hundred and thirty eyes from 130 subjects (mean age = 47.8 ± 16.8 years) including 77 males and 53 females were recruited. CCT was measured by ultrasound pachymetry, intraocular pressure was determined by non-contact tonometry, horizontal and vertical corneal diameters were measured with a ruler and central corneal curvature was measured by keratometry.

Results

The mean values obtained were as follows: CCT = 548.97 ± 34.28 μm, IOP = 15.61 ± 2.69 mmHg, average corneal curvature (AVK) = 42.98 ± 1.19 D, horizontal corneal diameter (HVID) = 11.39 ± 0.69 mm and vertical corneal diameter (VVID) = 10.51 ± 0.50 mm. There was a significant effect of age on CCT (r = −0.35, p < 0.001). A 10-year-increase in age was associated with a 7.0 μm decrease in CCT. Males had significantly wider HVID than females (p = 0.03). Subjects in older age groups have narrower HVID and VVID. Corneal curvature, corneal diameter and gender did not significantly affect CCT.

Conclusion

CCT of normotensive Nigerian adults decreases with increasing age. There was no correlation between CCT and IOP in normotensive subjects. CCT was not significantly influenced by gender, corneal curvature and corneal diameter.

Intra-observer and inter-observer variation of Hertel exophthalmometry

PURPOSE

This study investigated the intra-observer and inter-observer variation of Hertel exophthalmometry.

METHODS

Seventy normal Chinese adults had bilateral exophthalmometry performed by two examiners. The two examiners were masked to the measurement results. One examiner did the measurement twice and the other examiner measured it once; the order was randomised. The same Hertel exophthalmometer was used throughout the study. The Bland-Altman method was used to analyse the intra-observer and inter-observer agreement.

RESULTS

The mean intra-observer and inter-observer agreements on the interorbital distance (IOD) were +/-3.31 mm and +/-6.39 mm, respectively. The intra-observer exophthalmometry difference was -0.01 +/- 0.61 mm for the right eye and 0.09 +/- 0.56 mm for the left eye. Agreements were +/-1.19 mm and +/-1.09 mm for the right and left eyes, respectively. The inter-observer exophthalmometry difference was -0.61 +/- 0.89 mm for the right eye and -0.49 +/- 0.80 mm for the left eye. Agreements were +/-1.74 mm and +/-1.57 mm for the right and left eyes, respectively. There was no significant intra-observer difference but the inter-observer difference was significant on both the IOD and exophthalmometry.

CONCLUSION

Good intra-observer agreement was demonstrated using Hertel exophthalmometry. The inter-observer agreement was clinically acceptable.

Exophthalmometric values and their biometric correlates: The Kandy Eye Study

BACKGROUND

To determine normal exophthalmometric values for a Sri Lankan population and investigate their demographic, physical, refractive and ocular biometric correlates.

METHODS

The Kandy Eye study was a population-based, cross-sectional study. By randomized cluster sampling, 1721 eligible participants, who were 40 years old and over were identified; 1375 participated. Exophthalmometry was performed with Hertel's exophthalmometer. Participants' demographics including age, gender and ethnicity were recorded. Height, weight, body mass index, non-cycloplegic refraction and ocular biometry were measured with standardized methods. Summary statistical analysis was performed for exophthalmometric values and relationships with other factors were tested using Pearson product-moment correlation coefficient analysis, standard single and multiple linear regression analysis.

RESULTS

A total of 1341 subjects were included in the analysis. Exophthalmometric values for the population had a mean of 15.82 mm, standard deviation of 2.73 mm and range of 10.46-21.28 mm. Exophthalmometric values for men were significantly higher than women. There were no significant differences between the racial groups' exophthalmometric values (Sinhalese, Tamils, Moors). Exophthalmometric values were significantly correlated with age, gender, height, weight, body mass index, base and axial length but not to refractive spherical equivalents. Only gender, weight, base and axial length were independent predictors for exophthalmometric values after adjusting for confounders.

CONCLUSION

In this Sri Lankan population, our study provided the first reported estimates of a normal exophthalmometric range and determined gender, weight, base and axial length as its correlates. Sri Lankans are the first population to demonstrate this relationship between weight and exophthalmometric values and also showed that refraction is not a cause for pseudo-proptosis.

Normal values of hertel exophthalmometry in children, teenagers, and adults from Tehran, Iran

PURPOSE

The aim of this study was to present normative values of exophthalmometry in Iranian children, teenagers, and adults and find the effect of age, gender, height, weight, and laterality (right vs. left eye) on normal values of protrusion.

METHODS

In a population-based epidemiological study, ocular protrusion values (mm) were measured in 1063 randomly selected (stratified sampling method) normal subjects using the Hertel exophthalmometer. Weight and height were measured in all subjects.

RESULTS

There were 462 (43.5%) females and 601 (56.5%) males. The age ranged from 6 to 70 years (mean +/- SD = 20.3 +/- 10.9). Subjects were divided into three age groups (years); children (range: 6 to 12, mean: 9.2 +/- 1.6), teenagers (range: 13 to 19, mean: 15 +/- 1.4), and adults (range: 20 to 70, mean: 31 +/- 7.9). The mean (+/-SD) absolute ocular protrusion value was 14.2 +/- 1.8 in children, 15.2 +/- 1.9 for teenagers, and 14.7 +/- 2.3 for adults. Right and left eye protrusions were well correlated (r = 0.97, p < 0.0005 in children and adults and r = 0.95, p < 0.0005 in teenagers). However, right eye protrusion was significantly more than on the left side (p < 0.0005). Although males had more eye protrusion, the gender difference was not significant except for teenagers. Weight and height did not have a significant effect on eye protrusion. No individual had more than 2 mm of asymmetry (relative eye protrusion). Increasing age had a significant effect on the eye protrusion (r = +0.32 for children, r = +0.13 for teenagers, and r = -0.30 for adults; 0.001 < p < 0.0005). The ocular protrusion was positively correlated with increasing distance between the two lateral orbital rims (base) in all age groups (p < 0.0005).

CONCLUSIONS

Any eye protrusion of more than 17.8 mm for Iranian children, 19 mm for Iranian teenagers, and 19.3 mm for Iranian adults and relative eye protrusion of more than 2 mm warrants further clinical examination. Age and base value had a significant impact on normal eye protrusion values.

Telecanthus and hypertelorism in frontoethmoidal meningoencephaloceles and the surgical correction of these conditions: Part I. An orbital anthropomorphometric evaluation of the Khmer subpopulation of Cambodia

This is the first of the two parts of a paper concerning a novel method on the surgical treatment of orbital dysmorphisms, especially telecanthus (TC) and hypertelorism (HT). The normal orbital values of a given ethnic group is an essential factor in determining the degree of correction intended in that patient population. We did not find any data related to the normal orbital values in Khmer-Cambodians in whom we performed the corrective surgeries. Thus, the aims of this article are to evaluate the orbital morphometric data procured in Khmer-Cambodians and to analyze the contradictory definitions of TC and HT found in the literature. We measured the inner canthal distance, outer canthal distance, and interpupillary distance in 688 Khmer-Cambodians. The measured normal values are presented and compared with other Asian populations. We discovered that the Khmer-Cambodian orbital morphometry did not resemble the general conception of an Asian appearance, but rather showed a similarity to values found in Indians. Telecanthus and hypertelorism are frequent orbital dysmorphisms that, however, find conflicting definitions in the literature. By means of a short literature review, we have attempted to reorganize the multiplicity of definitions in orbital measurements, as well as clarify the confusing terminology used in TC and HT.

One-stage correction for blepharophimosis syndrome

PURPOSE

To classify the severity of blepharophimosis, describe associated features and their effects on the incidence of amblyopia and to recommend guidelines for surgical treatment and management of surgical complications.

METHODS

The case records of 23 patients with blepharophimosis syndrome were examined retrospectively. Patients' photographs and measurements were reviewed to analyse the severity of blepharophimosis, surgical techniques undertaken, surgical outcomes, and complications. Statistical analyses were performed using paired-sample t-tests to evaluate the surgical outcome and Spearman correlation to examine the influence of blepharophimosis on the interpalpebral fissure height (PFH).

RESULTS

Eighteen out of 23 (78%) patients underwent one-stage surgery before the age of 5 years. About 31% of these patients had amblyopia. Only two patients had a blepharophimosis ratio greater than 1.5 as poor result. Two out of 18 (11%) patients with PFHs more than 2 mm needed a repeat operation, but all five (100%) patients with s less than 2 mm (very severe ptosis) needed repeat operations.

CONCLUSIONS

The one-stage corrective procedure provided acceptable results both in function and cosmesis. However, patients with very severe ptosis required multiple stages of reconstruction for ptosis correction at an earlier age, after which correction of telecanthus and small horizontal palpebral fissure length followed at an older age.

Age-related changes in the normal sagittal relationship between globe and orbit

PURPOSE

To establish the pattern of change in globe protrusion with advancing age. The findings contribute to our understanding of orbital ageing, and are useful in the longitudinal assessment of patients with orbital disease, craniofacial abnormalities and trauma.

METHODS

Ocular protrusion from the lateral orbital rim to the corneal apex was measured in 653 Caucasians aged 21-80 years. Healthy subjects only were included in the study excluding those with ocular or orbital diseases. Measurements were taken using a single instrument and observer. Data were analysed for both sexes and each eye separately.

RESULTS

The mean exophthalmometry reading in both sexes (318 female and 335 male) was 19+/-2mm. Ninety-eight percent of readings between the two eyes were within 1mm of each other and no subject had greater than 2mm of asymmetry. In all groups there was a negative linear correlation between ocular protrusion and age. This correlation was found to be highly statistically significant in all groups (r=0.56-0.65, p<0.0001). There was no statistically significant difference between change in ocular protrusion with age between the left and right eye for females or males. This study demonstrates a strong association between ocular protrusion and age in a Caucasian population. This association is an almost linear reduction in ocular protrusion with increasing age between the ages of 31 and 80. Asymmetry in ocular protrusion between the two eyes does not develop with increasing age.

High Altitude and the Eye: A Case Controlled Study in Clinical Ocular Anthropometry of Changes in the Eye

Tribal natives of two spatially separate districts of Lahaul-Spiti (mean altitude = 3300 m) and Kinnaur (mean altitude = 1,700 m) in the Himalayan state of Himachal Pradesh have lived for centuries as closed isolated groups, marrying within the local community up to the recent past. Studies on highland natives in the Andes have shown differences in chest diameters, lung volumes, hematocrit, and the like, in those living at high altitudes. We wanted to study whether stay at high altitude for generations confers any change in the ocular anthropometry. No study of this nature is available in the literature. We studied the ocular parameters using Snellen's charts, Standard Royal-Air-Force Rule, A-2,500 Sonomed A-Scan, Goldmann's aplanation tonometer, and S-7,000 Autorefractometer on 50 healthy volunteers at the Indira Gandhi Medical College Out Patient Department at Shimla (mean altitude = 2,100 m). Those living at higher altitudes in Lahaul-Spiti [LS] (n = 10) had significantly wider nose bridge width (p < 0.05); inter-inner canthal distance [IICD] (p < 0.05); inter-outer canthal distance [IOCD] (p < 0.05); and interpupillary distance [IPD] (p < 0.05) than the group living at Kinnaur (n = 40) at lower elevation. The LS group also had narrower palpebral fissure length in the vertical dimension (p = 0.05) and a lower IOP (p = 0.002) than the Kinnaur group. The axial length, lens thickness, and anterior chamber depth were comparable in the two groups. It appears that the eye and its adnexa respond to hypoxia, ultraviolet radiations, and persistent snow cover at high altitude by altering its anthropometry in a subtle but discernible manner. This was a hitherto unexplored area in the literature. Further studies to elucidate and substantiate the findings of the study are indicated.

Craniofacial anthropometry of Hong Kong Chinese babies: the eye

OBJECTIVES

To provide a database of the canthal measurements of Chinese infants born in Hong Kong.

DESIGN

Prospective cross-sectional study.

SETTING AND SAMPLE POPULATION

A total of 2,371 healthy singleton, born consecutively at the Prince of Wales Hospital and the Union Hospital from June 1998 to June 2000, were included in the study. The range of gestation was 33-42 weeks.

MEASUREMENTS AND RESULTS

Canthal parameters were measured and included the outer canthal distance (OCD), intercanthal distance (ICD) and palpebral fissure length (PFL). The data generally show higher values for males in the parameters measured. The measurements were also compared with data published overseas. PFL and OCD were significantly larger in Hong Kong Chinese newborn babies, whereas ICD was smaller.

CONCLUSION

This study establishes the first set of gestational age-specific standard of such craniofacial parameters for Chinese newborn babies, potentially enabling early syndromal diagnosis. There are significant inter-racial differences in these canthal parameters.

Normal values and standard deviations for pupil diameter and interpupillary distance in subjects aged 1 month to 19 years

Normal values of pupil diameters and interpupillary distances (PDs) were measured in a population of 1311 subjects (in 4294 visits) ranging from 1 month of age to slightly over 19 years of age. Subjects in this study were recruited from birth announcements in a local newspaper for a developmental vision project. Pupil sizes were measured photographically when the corneas were illuminated by 15.9 +/- 0.5 lux ambient illumination (i.e. under mesopic conditions). Interpupillary distance was measured with an interocular distance rule while the subject fixated an object at 0.66 m distance. These PD measurements were corrected for systematic measurement errors and to an infinite viewing distance using radii of ocular rotation based on age-dependent axial lengths. Means and S.D. were calculated for age, pupil diameter and PD for each 1-year group of male and female subjects. The second order regression equation for average pupil size as a function of age was determined: [males pupil diameter (in mm) = 5.83 +/- 0.181*age in years - 0053*age in years2, r2 = 0.897; female pupil diameter = 5.40 + 0.285*age in years - 0.0109*age in years2, r2 = 0.945]. The dierence between male and female pupil sizes (mean male - female = 0.13 mm) was marginally not significant (p < 0.054). The average corrected PDs as a function of age were found to approximate another second-order regression equation: (males PD = 43.36 + 1.663*age in years - 0.034*age in years2, r2 = 0.986; females PD = 41.76 + 1.891 *age in years - 0.052*age in years2, r2 = 0.986). Male PD was wider than female PD by an average of 1.58 mm (p < 0.0003). As expected, the results of this study were similar to a preliminary investigation conducted by Thunyalukul et al. [Invest. Ophthalmol. Vis. Sci. 37 (1996) S731] on a portion of the present data set, and also very similar to data from another study of comparable racial composition using a different measurement method [Pryor, Pediatrics 44 (1969) 973]. It was concluded that pupil diameter and PD increase more gradually than axial length of the eye in the first few years of life. The normal values and S.D. for both pupil size and PD determined in this study have important clinical implications as well as applications in the optical industry.

Craniofacial anthropometry in a Turkish population

OBJECTIVE

To present norms and demonstrate the anthropometric variations in fronto-occipital circumference, inner and outer canthal distances, near and distant [far] anatomical interpupillary distance, canthal index, and circumference-interorbital index across age and sex in urban Turkish subjects.

PARTICIPANTS

Three thousand four hundred forty-eight subjects (1852 male, 1596 female) aged 7 to 40 years were included in this study.

METHODS

Three age groups were studied: children aged 7 to 15 years, young adults aged 16 to 25 years, and adults aged 26 to 40 years. Mean values for each measured parameter were determined at each age between 7 and 25 years. Subjects were also divided into nine age subgroups to observe the change of each parameter with advancing age.

RESULTS

The fronto-occipital circumference and outer canthal distance of males was significantly (p <.001) wider than females in all age groups. The near and distant interpupillary distances of male subjects were, on average, wider than the female subjects with greater differences with advancing age. Across all subjects aged 7 to 40 years, the mean of all measured parameters and calculated indexes of men and boys was significantly different from girls and women (p <.001). The mean for interpupillary distances in our study in both sexes were found to be similar to Arabian, Hong Kong, and British children; larger than those of Chinese, Black, Indian, and Caucasians; and smaller than those of Mexican children and a mixed European population.

CONCLUSION

This study clearly shows the anthropometric variation for fronto-occipital circumference, inner canthal distance, outer canthal distance, near and distant interpupillary distance, canthal index, and circumference-interorbital index with age. These developmental data and the normal values of these measurements in healthy subjects are useful for dysmorphologists in the early identification of some craniofacial syndromes, hyper- and hypotelorism, and congenital or posttraumatic telecanthus and of planning surgical intervention. We suggest that the comparison of craniofacial dimensions of a patient must be performed with normal standards specific for age as well as sex and race.

Interpupillary index: a new parameter for hypo-hypertelorism

AIM

To establish a new clinical index to evaluate the presence of hypo-hypertelorism with greater accuracy.

MATERIAL AND METHODS

After screening a wide range of population, 310 elementary school children (185 boys, 125 girls) aged 7-15 years were included in this study. For this cross-sectional study, a millimetre ruler was used. The anatomical interpupillary distance was measured by a modified Viktorin's method. In addition, inner and outer intercanthal distances were obtained. The data were analyzed by Student's t-test for two independent samples using SPSS for Windows. There were children with clinical hypertelorism (n = 92, group 1), children with large fronto-occipital circumference (FOC) (n = 101, group 2), and age- and sex-matched normal controls (n = 117, group 3). Due to variations in FOC among healthy subjects, we introduced a new practical concept for evaluation of interpupillary distance, namely the interpupillary index, the simple product obtained by dividing the interpupillary distance by the FOC, multiplied by 100.

RESULTS

The overall idiopathic benign macrocephalic children (group 2) had significantly (p < 0.001) larger interpupillary distances (6.13 +/- 0.36 cm) and FOCs (56.99 +/- 1.46 cm) than those of normal controls (5.70 +/- 0.26cm and 52.82 +/- 1.22 cm, respectively). But, the difference between the combined product of interpupillary distance and FOC, the interpupillary index, was not significant (10.76 +/- 0.50 and 10.79 +/- 0.35, respectively) (p > 0.05). On the other hand, the children with hypertelorism had significantly (p < 0.001) larger interpupillary distances (6.47 +/- 0.29cm) and FOCs (54.90 +/- 2.18cm) when compared with the controls. In addition, the interpupillary index was significantly (p < 0.001) higher (11.80 +/- 0.45) than both macrocephalic children (10.76 +/- 0.50) and controls (10.79 +/- 0.35). Intercanthal distances and intercanthal index of hyperteloric children were also significantly (p<0.001) larger than both macrocephalic children and controls.

CONCLUSION

This new index offers a new concept for more accurate evaluation of the presence of ocular hypo-hypertelorism.

Anatomic factors affecting microkeratome placement in laser in situ keratomileusis(2)(2)

PURPOSE

To identify the significant anatomic factors that affect placement of 2 microkeratomes and compare the ease of their placement.

SETTING

The Laser Center, Houston, Texas, USA.

METHODS

Anatomic factors affecting microkeratome placement were evaluated in 250 eyes of 137 myopic patients in a prospective consecutive-enrollment study. Anatomic factors measured included vertical orbital width, horizontal interpalpebral fissure (HPF), corneal diameter, and position of the corneal apex relative to the lateral orbital rim (PCL). Vertical orbital width and HPF were measured with a micrometer caliper (Mitutoyo); corneal diameter, with Orbscan topography (Bausch & Lomb Surgical); and PCL, with a Hertel exophthalmometer. Patients were randomly divided into 2 groups (125 eyes/group) to have surgery with the Automated Corneal Shaper((R)) (ACS) (Bausch & Lomb Surgical) or Hansatome (Bausch & Lomb Surgical) microkeratome. Microkeratome placement was graded by 1 surgeon as "easy" (grades 1, 2, and 3) or "difficult" (grades 4 and 5). Results were correlated with anatomic factors to evaluate possible anatomic influences on the difficulty of microkeratome placement.

RESULTS

The PCL and vertical orbital width were statistically significant factors in predicting the difficulty of ACS microkeratome placement (P <.05). For the Hansatome microkeratome, since only 1 eye was graded as a difficult placement, the anatomic parameters affecting placement could not be evaluated. There were no statistically significant between-group differences in mean age and means of all anatomic factors measured (independent t test, P >.05). Difficult applanations were encountered in the ACS group (8/125 eyes, 6.4%) more than in the Hansatome group (1/125 eyes, 0.8%), which was a statistically significant difference by the Pearson chi-square test (P <.05).

CONCLUSIONS

The PCL and vertical orbital width were significant anatomic factors affecting placement of the ACS microkeratome. The anatomic factors affecting Hansatome microkeratome placement could not be determined. The percentage of difficult placements was significantly lower with the Hansatome than with the ACS.

The far interpupillary distance. A gender-specific variation with advancing age

A knowledge of the magnitude of the far interpupillary distance (FIPD) in relation to a specific population is of clinical, practical and theoretical interest. A FIPD database is presented here, comprising material collated from the spectacle dispensing records of n = 1800 subjects seen in routine optometric practice. All measurements were taken by the author on healthy Caucasian (white, Northern European) males and females. The data were equi-partitioned either across three age bands (16-25, 26-40, 41-65 years: mixed refractive types, total n = 900) or between the three distance refractive types (emmetropia, hypermetropia, myopia: all subjects aged between 41-65 years, total n = 900). A consistent gender difference (male > female) was confirmed throughout this material, irrespective of age group; refractive type, however, had no influence on the magnitude of this facial parameter. Summary results of this anthropometric survey are presented in tabular form, facilitating reference by ophthalmic and dental clinicians and by the designers of binocular optical instruments. There was also revealed evidence of a gender-specific pattern of change in the FIPD variable with advancing age. An approximately 3% increase in the magnitude of the human FIPD from the mid-teens to later middle age was attained in males by early middle age, being little altered thereafter: in contrast females continued to record an increase in this facial parameter into later middle age. An explanation for this hitherto unremarked feature of human facial anthropometry might be sought in the gender-specific changes post-puberty of the cranial skeletal anatomy and in the soft tissues of the orbital region.

Evaluation of results with three-point visualization of zygomaticomaxillary complex fractures

OBJECTIVE

To retrospectively evaluate the results of three-point visualization and liberal rigid fixation for the treatment of unilateral zygomaticomaxillary fractures by assessing the incidence and severity of complications.

STUDY DESIGN

Fourteen patients were examined an average of 19 months after 3-point visualization with multiple points of rigid fixation for their unilateral zygomaticomaxillary fractures. Patients were evaluated for asymmetry in globe position, superior tarsal fold size, diplopia, lateral canthus height, and malar projection.

RESULTS

The following were found: two patients with significant changes in globe position, none with diplopia in direct gaze, two with diplopia in extreme gazes, two with severe tarsal fold asymmetry, five with mild tarsal fold asymmetry, and two with noticeable malar asymmetry.

CONCLUSION

Three-point visualization and liberal rigid fixation for zygomaticomaxillary fracture treatment results in a low incidence of complications that are proportional in severity to the trauma sustained.