Utilizing a mobile platform to obtain quantitative measurements of exophthalmos.

PURPOSE: This study introduces a novel exophthalmometry method utilizing a mobile platform to obtain calibrated quantitative measurements of globe position and compares its reliability to Hertel exophthalmometry. METHODS: A prospective, comparative study included 50 patients (99 eyes) for a total of 594 mobile measurements. Healthy individuals from the community in Augusta, Georgia, and individuals from a routine oculoplastics clinic at Mayo Clinic in Rochester, Minnesota, were included to represent variety within the population. The main outcome was the inter-modality correlation and agreement between Hertel and mobile exophthalmometry, and the intra-observer and inter-observer reliability with repeated mobile measurements. RESULTS: There was no significant difference in the measurements obtained by Hertel exophthalmometry and mobile exophthalmometry. There was a strong linear correlation between Hertel and mobile exophthalmometry with a Pearson Correlation Coefficient of 0.910 and 0.888 for the right and left eyes, respectively (p < .001, 2-tailed). Bland-Altman plot analysis showed excellent agreement between the two modalities. The mobile platform demonstrated high intra-observer reliability with a Cronbach's alpha of 0.992 and 0.985 for the right and left eyes. An intraclass correlation coefficient of 0.992 (95% CI: 0.987-0.995) for the right eye and 0.986 (95% CI: 0.978-0.991) for the left eye demonstrated excellent reliability between observers. CONCLUSIONS: Mobile exophthalmometry may be a promising tool for obtaining calibrated quantitative measurements of globe position for situations in which Hertel exophthalmometry is not available. The strong correlation and excellent agreement between Hertel and mobile measurement suggest that mobile exophthalmometry can yield reliable and accurate measurements.

Validation of exophthalmos magnetic resonance imaging measurements in patients with Graves' orbitopathy, compared to ophthalmometry results.

Purpose: Although assessment of the orbital structures using magnetic resonance imaging (MRI) is well described in the literature, there is no consensus as to which measurement method is the most useful in exophthalmos assessment. The aim of the study was to correlate 2 MRI methods of exophthalmos measurement with exophthalmometry results and to determine a proper technique of exophthalmos measurement. Material and methods: Fifty-four patients (108 orbits) with exophthalmos in the course of Graves' orbitopathy were enrolled in the study. Two measurements on axial T2W orbital MRI images were performed by 2 independent radiologists: the distance from the interzygomatic line to the anterior surface of the globe (AD) and the distance from the interzygomatic line to the posterior sclera (PD). Within 4 weeks, an exophthalmometry was performed by an ophthalmologist using a Hertel exophthalmometer. The inter-observer variation was assessed using the Pearson correlation coefficient. Values were presented as mean and standard deviation, and the differences in values were explored with Student's t-test. Results: The mean AD measured on MRI by the first observer was 20.6 ± 3 mm, and 20.6 ± 2.9 mm by the second observer. PD values were 2.9 ± 2.8 mm and 3.4 ± 2.8 mm, respectively. The mean exophthalmometry result was 21 ± 3.3 mm. The correlation was very high between observers for AD measurements (r = 0.98, p = 0.01) and high for PD measurements (r = 0.95, p = 0.01). AD measurements on MRI and exophthalmometry results were strongly correlated (r = 0.9, p = 0.01). Conclusions: The AD measurement has better reproducibility and is directly correlated with Hertel exophthalmometry. This method could be sufficient in routine practice.

[Comparison of Measurement Methods of Exophthalmos and Its Forensic Significance].

OBJECTIVES: To compare the differences between Hertel exophthalmometry and CT on exophthalmos measurement, and explore its practical application value in forensic medicine. METHODS: Fifty-six normal individuals without eye injuries or diseases were selected as the control group. The absolute values of exophthalmos were measured in the standardized CT image workstation. The difference of binocular exophthalmos was compared in normal group. Forty-seven cases with unilateral orbital fracture were divided into injured eye group and normal eye group according to the presence of binocular orbital fractures. The differences of the absolute values of eophthalmos from the same eye and the relative values of eophthalmos between two eyes for same person measured by Hertel exophthalmometry and CT were analyzed. RESULTS: There was no statistical difference of exophthalmos between the normal eyes measured by CT method. In the normal eye group, the absolute value of exophthalmos measured by CT method was （16.66±5.41） mm, which was （16.16±4.45） mm when measured by the Hertel exophthalmometry method. There was no statistical difference between two groups （P>0.05）. In the injured eye group, there was statistical difference between the absolute values of exophthalmos measured by two measurement methods （ P<0.05）. There was no statistical difference of the relative values of exophthalmos between the injured eyes and the normal eyes by two measurement methods （P>0.05）. CONCLUSIONS: CT method has a good consistency with Hertel exophthalmometry, which can be applied into the practice of medicolegal expertise.

A Comparison of Lower Eyelid Retraction in Normal Individuals with Positive versus Negative Orbital Vector.

PURPOSE: The present study aimed to compare lower eyelid retraction (LER) in individuals with a positive orbital vector with that of individuals with a negative orbital vector. MATERIALS AND METHODS: This cross-sectional study was conducted on 123 normal individuals including 64 men and 59 women aged 20-80 years. After the individuals underwent Hertel exophthalmometry, two side-view and front-view photos were taken using a camera. The orbital vector angle and the extent of scleral show were then measured in millimeter, using the Photoshop software. Eventually, the recorded data were analyzed through statistical software. RESULTS: The findings of this study showed that LER has a significant correlation with orbital vector angle and the extent of proptosis (P < 0.05). The mean value of orbital vector angle in individuals without LER was 9.76°, while this figure was calculated to be - 13.65° in individuals with LER. The mean protrusion value based on Hertel exophthalmometry was 14.08 mm in individuals without LER and 16.27 mm in individuals with LER. The extent of scleral show had a significant correlation with proptosis and orbital vector angle (P = 0.01), with a mean value of - 0.41 mm in individuals without LER and 0.94 mm in participants with LER. CONCLUSIONS: The prevalence of LER and scleral show is positively correlated with the extent of proptosis and negatively correlated with orbital vector angle.

Eye motion increases temporal visual field extent.

PURPOSE: To study the impact of eye motion on visual field extent. METHODS: Visual fields were tested in 15 healthy volunteers with the Goldmann perimeter using a V4 test object, from seen to unseen, first in primary position of gaze, then allowing eye motion. Temporal points falling out of the cupola were tested again after a controlled nasal head rotation using a headband prototype fitted with a line-laser level having two orthogonal vial levels. Visual field surface areas (cm(2) ) were calculated as projections on a 30-cm virtual Goldmann cupola, whose extent would have been large enough to include all points. Reproducibility error of the method assessed by calculation of the relative difference between surface areas of 12 visual field tests and 12 visual field retests was estimated at 14%. Hertel exophthalmometry was recorded to study the influence of globe position on visual field extent. RESULTS: Binocular visual field surface area increased by 37% with eye motion (p-value=1.20·10(-9) ). This increase was highest (46%; p-value=1.2·10(-24) ) in the temporal quadrant. Median maximal visual field temporal eccentricity with eye motion was 128.3° (minimum: 109.5°; maximum: 137.7°) and more than 135° in four eyes of three subjects. Hertel exophthalmometry was positively linked to visual field temporal surface area with eye motion (p-value=0.013). CONCLUSIONS: Eye motion greatly expands the temporal visual field. This peculiarity is likely an adaptation to terrestrial life with upright bipedal locomotion and may save head movements through horizontal eyeball scanning.

Comparison of Measurement Methods of Exophthalmos and Its Forensic Significance / 法医学杂志

Objective To compare the differences between Hertel exophthalmometry and CT on exophthalmos measurement,and explore its practical application value in forensic medicine.Methods Fifty-six normal individuals without eye injuries or diseases were selected as the control group.The absolute values of exophthalmos were measured in the standardized CT image workstation.The difference of binocular exophthalmos was compared in normal group.Forty-seven cases with unilateral orbital fracture were divided into injured eye group and normal eye group according to the presence of binocular orbital fractures.The differences of the absolute values of eophthalmos from the same eye and the relative values of eophthalmos between two eyes for same person measured by Hertel exophthalmometry and CT were analyzed.Results There was no statistical difference of exophthalmos between the normal eyes measured by CT method.In the normal eye group,the absolute value of exophthalmos measured by CT method was (16.66±5.41) rm,which was (16.16±4.45)mm when measured by the Hertel exophthalmometry method.There was no statistical difference between two groups (P＞0.05).In the injured eye group,there was statistical difference between the absolute values of exophthalmos measured by two measurement methods (P＜0.05).There was no statistical difference of the relative values of exophthalmos between the injured eyes and the normal eyes by two measurement methods (P＞0.05).Conclusion CT method has a good consistency with Hertel exophthalmometry,which can be applied into the practice of medicolegal expertise.

Usefulness of Exophthalmos Measurement on Upgaze

PURPOSE: To evaluate the usefulness of exophthalmos measurement on upgaze in patients who are not able to expose corneal vertex on primary gaze. METHODS: The present study included 39 patients with blow out fracture, pseudotumor, or thyroid associated ophthalmopathy and 21 people who don't have any ocular disease. In total, 60 people had exophthalmometry using Hertel exophthalmometer on the basis of corneal vertex, inferior limbus, and inferior sclera by three examiners. RESULTS: The relative exophthalmometry in normal group was 0.71 +/- 0.75 mm, 0.67 +/- 0.62 mm, and 0.69 +/- 0.60 mm on the basis of corneal vertex, inferior limbus, and inferior sclera, respectively. The relative exophthalmometry in exophthalmic group was 1.10 +/- 0.99 mm, 1.13 +/- 0.99 mm, 1.10 +/- 0.91 mm on the basis of corneal vertex, inferior limbus, and inferior sclera, respectively. The relative exophthalmometry in enophthalmic group was 0.79 +/- 0.90 mm, 0.74 +/- 0.92 mm, 0.74 +/- 0.87 mm on the basis of corneal vertex, inferior limbus, and inferior sclera, respectively. There was no statistically significant difference between different measuring points (p > 0.05). The inter-examiner reproducibility was shown to be highly reliable. CONCLUSIONS: The upgaze exophthalmometry on the basis of inferior limbus or inferior sclera would be useful in the patients who are not able to expose corneal vertex on primary gaze.