Relationship between the computed tomographic volumetry of the eyeballs and lacrimal glands in a Nigerian population

Aim:

The aim of this article was to obtain measurements of the eyeballs/globes and lacrimal glands in normal subjects using cranial computed tomography (CT) scan. Understanding the normative approximations of these measurements could help in diagnosing and evaluating orbito-ocular pathologies.

Materials and Methods:

This retrospective study examined 220 globes/eyeballs and 220 lacrimal glands of 110 consecutive participants. The eyeball volume was calculated using both the ellipsoid and spherical formulas, whereas lacrimal gland volume was approximated using the ellipsoid formula only.

Results:

The mean age of the subjects was 51.18 ± 14.85 years and ranged from 22 to 85 years. The study population was 53.6% male (n = 59) and 46.3% female (n = 51). The mean volumes of all globes in this study were 5.82 ± 0.77 and 5.98 ± 0.75 cm3 using the ellipsoid and spherical formulae, respectively. The mean volume of all lacrimal glands was 0.42 ± 0.14 cm3 using the ellipsoid formula. The mean globe volumes using the ellipsoid and spherical formulae (6.02 ± 0.84 and 6.02 ± 0.84 cm3) in males were significantly larger than the corresponding mean globe volumes in females (5.59 ± 0.62 and 5.80 ± 0.65 cm3) (P < 0.0001 and P = 0.001, respectively). There was no significant difference between the lacrimal gland volumes of males (0.42 ± 0.14 cm3) and females (0.42 ± 0.14 cm3) (P = 0.84).

Conclusion:

Males have larger eyeball/globe volumes than females. Eyeball and lacrimal gland volumes did not correlate significantly. Eyeball volume showed an inverse relationship with age. Age did not affect lacrimal gland volume.

The Change of Lacrimal Gland Volume in Korean Patients with Thyroid-associated Ophthalmopathy

PURPOSE

To describe the change of lacrimal gland volumes in Korean patients with thyroid-associated ophthalmopathy (TAO) via computed tomography (CT).

METHODS

A retrospective review of CT images from 217 TAO patients and 135 control subjects was performed. The TAO patients were diagnosed between May 2005 and May 2014 and had a CT performed on initial presentation (330 orbital CT scans). These images were compared with 270 orbital CT scans from the control group, obtained between May 2013 and May 2014. An open source DICOM viewer was used to calculate the volume of the lacrimal gland.

RESULTS

The mean volume of the lacrimal gland in TAO patients was 0.816 cm³ in the right orbit (standard deviation [SD], 0.048) and 0.811 cm³ in the left orbit (SD, 0.051), with no significant difference between right and left (p = 0.192). However, significant differences were observed between TAO patients and healthy individuals (p < 0.001). There was no significant difference between mean lacrimal gland volumes of males (0.812 cm³; SD, 0.037) and females (0.816 cm³; SD, 0.029) (p = 0.513). There was a negative correlation between gland volume and age in TAO patients (Pearson r = -0.479, p = 0.00). The subjective tearing (right: r = 0.244, p = 0.018; left: r = 0.226, p = 0.024), corneal superficial punctate keratopathy (right: r = 0.192, p = 0.040; left: r = 0.206, p = 0.036), and exophthalmometry (right: r = 0.182, p = 0.032; left: r = 0.180, p = 0.046) correlated with lacrimal gland volume.

CONCLUSIONS

This study is the first to use CT images to calculate the lacrimal gland volume of Korean TAO patients. In TAO patients, the lacrimal gland volume was notably increased compared to control subjects. The lacrimal gland volume decreased with age, but there was no difference between gender and no difference between left and right. The lacrimal gland volume correlated with subjective tearing, corneal superficial punctate keratopathy and exophthalmometry.