Computed tomographic dimensions of the lacrimal gland in healthy orbits

Comparison of lacrimal gland dimensions and volume in unilateral Ahmed glaucoma valve versus trabeculectomy

PURPOSE

To evaluate radiographic lacrimal gland (LG) volume and dimensions in Ahmed glaucoma valve (AGV)- versus trabeculectomy-treated eyes and contralateral non-treated eyes.

METHODS

In this retrospective cohort study, 1616 medical records acquired between 2010 and 2020 were examined. In AGV-treated (group 1) eyes, there were 19 patients with records sufficient for radiological LG evaluation, and in trabeculectomy-treated (group 2) eyes, there were 18. The hospital workstation software was used to assess high-resolution computed tomography (HRCT) scans conducted under standard protocol using a 128 SL Optima CT 660 scanner. The software (Vitrea™) was used to perform semi-quantitative volumetric measurements. LG dimensions were obtained in the axial and reformatted coronal planes on each side, and four measures were generated using the widest LG tip-to-tip diameters in two planes: coronal length, coronal width (CW), axial length (AL), and axial width.

RESULTS

The time interval between surgery and HRCT imaging was 50.97 ± 26.25 months. Group 1 had significantly lower LG volume than group 2 (594.11 ± 259.45 vs. 933.67 ± 294.09 mm3, P = 0.001). When compared to non-treated eyes, AGV-treated eyes had lower LG volume (P = 0.065) while trabeculectomy-treated eyes had higher LG volume (P = 0.031). Further, group 1 had decreased length and width in both the axial and coronal planes as compared to group 2, with AL and CW being significantly different (P < 0.05).

CONCLUSIONS

AGV and trabeculectomy had varied impacts on LG volume and dimensions despite being conducted in the same quadrant. HRCT appears to be effective in analysing AGV position, which may be related to LG volumetric and dimensional issues.

Radiological measurements of lacrimal gland in thyroid eye disease

PURPOSE

Lacrimal gland enlargement is a common feature of thyroid eye disease (TED) and has been positively correlated with the clinical activity score. Although lacrimal gland volume is the preferred measure of lacrimal gland size, its calculation is not clinically translatable due to the expertise, time and advanced software required. The aim of our study is to determine whether the lacrimal gland volume in patients with TED undergoing magnetic resonance imaging (MRI) can be estimated using simpler lacrimal gland linear and area measurements.

METHODS

A retrospective review of 102 orbits (51 patients) with TED who underwent orbital MRI was conducted. The maximum length, width, and area of the lacrimal gland were measured in axial and coronal sections. Lacrimal gland volume was calculated by using a manual segmentation technique on all consecutive axial slices on commercially available software, OsiriX. All quantitative measurements were correlated with the lacrimal gland volume.

RESULTS

Mean age of participants was 59 ± 16 years, and 67% (n = 34) were females. With multivariate analyses, combined lacrimal gland axial and coronal areas strongly correlated with volume (r = 0.843, p < 0.01). Strong univariate predictors of volume included axial area (r = 0.704, p < 0.01) and coronal area (r = 0.722, p < 0.01), while moderate predictors included axial length (r = 0.523, p < 0.01), axial width (r = 0.521, p < 0.01), coronal length (r = 0.450, p < 0.01), and coronal width (r = 0.649, p < 0.01).

CONCLUSION

In patients with thyroid eye disease, lacrimal gland volume can be estimated using axial and coronal areas, which is simpler and more time efficient than calculating volumes.

Ocular Surface Evaluation in Immunoglobulin G4-Related Ophthalmic Disease

PURPOSE

To evaluate the functional and structural changes of the meibomian glands and ocular surface in immunoglobulin G4-related ophthalmic disease (IgG4-ROD) patients.

DESIGN

Cross-sectional, matched case-control comparison study.

METHODS

This study included 64 patients with biopsy-proven IgG4-ROD (aged 63.4 ± 12.2 years, 39 male) and 64 sex- and age-matched healthy controls. Patients were managed by hospitals covering the publicly funded ophthalmology service in Hong Kong. Outcome measures included anterior segment examination and keratographic and meibographic imagings.

RESULTS

A total of 64 worst-affected eyes of the 64 IgG4-ROD patients were analyzed. Corneal fluorescein staining (P = .0187), lid margin telangiectasia (P = .0360), lid-parallel conjunctival folds (P = .0112), papillae (P = .0393), meibomian gland plugging (P = .0001), meibomian gland expressibility (P = .0001), and meibum quality (P = .0001) were more significant in IgG4-ROD patients compared with healthy controls. Both upper and lower meibomian gland dropouts (P = .001 and .0003), and tear meniscus height (P = .0001) were higher in IgG4-ROD patients. Non-invasive tear break-up time (NITBUT) (P = .0166) and Schirmer test results (P = .0243) were lower in IgG4-ROD patients. Upper (r = 0.336, P = .0140) meibomian gland dropouts and NITBUT (r = -0.293, P = .0497) were positively and negatively correlated with the IgG4-ROD onset age, respectively. The number of extraocular organ involvement was negatively correlated with the Schirmer test(r = -0.341, P = .0167). Lower NITBUT was found in IgG4-ROD eyes with lacrimal gland enlargement than in IgG4-ROD eyes without lacrimal gland enlargement radiologically (P < .0001).

CONCLUSIONS

IgG4-ROD patients showed features of both aqueous tear deficiency and evaporative dry eye disease. We recommend ocular surface evaluation to all patients newly diagnosed with IgG4-ROD. Further studies are warranted to clarify the mechanism of IgG4-related dry eye disease.

Morphometric and volumetric analysis of lacrimal glands in patients with thyroid eye disease

Assessment of morphometric and volumetric changes in lacrimal glands in thyroid eye disease, its clinical manifestations in relation of disease progression. Retrospective volumetric analysis included both genders and was performed on total of 183 patients - 91 patients with diagnosed Grave's disease and thyroid eye disease and 92 patients without Grave's disease and thyroid eye disease who underwent multidetector computed tomography (MDCT) examination in routine daily work according to other medical indications. In the group of females, there was statistical significance between patients with thyroid eye disease and controls who were smoking and had body weight gain. We found statistical significance in volumetric enlargements for both orbits in both genders for the patients group when compared to controls. There was also statistical significance in morphometric characteristics for the lacrimal gland diameters measured. Determination planimetric morphometric parameters of importance were coronary height of lacrimal gland of the right eye, coronary height of lacrimal gland of the left eye and coronary width of lacrimal gland of the left eye for the group of males. In a group of females the established determination parameters of importance were the coronary height of lacrimal gland of the left eye, the axial width of lacrimal gland of the left eye, volume of lacrimal gland of the right eye and the volume of lacrimal gland of the left eye. When we compared the displaced lacrimal gland coming forward (proptosis) in time progressing disease between group of patients and controls, we also found statistical significant connection. Evaluation of lacrimal gland volumetric and morphometric data may increase validity of defining this anatomical substrate and its morphology disruption as liable tool for thyroid eye disease progression follow up and treatment planning and outcome.

Normative lacrimal gland dimensions by magnetic resonance imaging in an Australian cohort

PURPOSE

To report the normative dimensions of the lacrimal gland on fat-suppressed contrast-enhanced magnetic resonance imaging (MRI) in an Australian cohort.

METHODS

Retrospective review of patients who underwent 3 T orbital MRI is presented. Two hundred eleven orbits were used to conduct lacrimal gland measurements. Orbits were excluded if there was ipsilateral orbital or lacrimal gland disease, prior surgery, or poor image quality. The length and width of the lacrimal gland were measured in axial and coronal sections using the largest image.

RESULTS

The mean lacrimal gland axial length was 14.6 mm in the right orbit and 14.3 mm in the left orbit. The mean axial width was 4.9 mm in both orbits. Coronal lengths averaged 16.2 mm in the right orbit and 16.4 mm in the left orbit. The coronal width averaged 4.8 mm in both orbits. A significant negative correlation was found between age and the right axial length (r = -0.26, p < .01) and the left axial length (r = -0.26, p < .01) of the lacrimal gland. No statistically significant difference was found between genders or laterality.

CONCLUSION

This study presents the normal lacrimal gland dimensions on fat-suppressed contrast-enhanced MRI in an Australian cohort. An inverse relationship exists between age and the axial length of the lacrimal gland. These data may be used to help diagnose enlargement of the lacrimal gland.

Normative orbital measurements in an Australian cohort on computed tomography

PURPOSE

To determine the normal diameters of the extraocular muscles (EOMs) and optic nerve sheath complex (ONSD) and correlate with patient demographics in an Australian cohort.

METHODS

Consecutive patients who underwent contrast enhanced computed tomography (CT) orbits between December 2017 and March 2021 were included. Patients with bilateral disease, previous orbital surgery, or poor scan quality were excluded. Normal orbit was used in patients with unilateral orbital disease.

RESULTS

Two hundred one orbits from 201 patients were included. Normal measurements (mean ± SD) were as follows: medial rectus (MR) 4.22 ± 0.56 mm; inferior rectus (IR) 4.20 ± 0.70 mm; lateral rectus (LR) 3.40 ± 0.56 mm; superior muscle group (SMG) 4.13 ± 0.72 mm; superior oblique (SO) 2.60 ± 0.43 mm; inferior oblique (IO) on quasi-sagittal plane 2.19 ± 0.42 mm, and the ONSD 5.62 ± 0.82 mm. The mean diameters of the LR, SMG, IR, SO, and ONSD were significantly larger in male than female patients (p < .05). Statistically significant correlation was found between age and the diameters of the LR (r = 0.29, p < .01), SMG (r = 0.22, p < .01), IO on a coronal plane (r = -0.18, p < .01), and ONSD (r = 0.16, p = .02).

CONCLUSION

This normative data may be used to diagnose pathological enlargement of the optic nerve and extraocular muscles, including involvement of the oblique muscles.

Delineation of the lacrimal vein: a magnetic resonance imaging study

PURPOSE

To our knowledge, anatomical knowledge about the lacrimal vein (LV) is missed. Therefore, this retrospective study aimed to explore them using magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Eighty-one patients who underwent contrast-enhanced MRI and three donated bodies to science were enrolled.

RESULTS

On the sagittal images, the measured mean right long (LD) and short diameters (SD) of the lacrimal gland (LG) were 17.3 ± 2.4 mm and 13.7 ± 2.1 mm, while the left LD and SD were 17.0 ± 2.6 mm and 13.6 ± 2.6 mm, respectively. Laterality or sex differences were not found in the LD and SD groups. In addition, no specific age range was associated with a significantly longer LD or SD. LVs were identified in 94% of axial images. Their course was classified into as follows: three types: connecting to the superolateral cavernous sinus (CS), to the superior ophthalmic vein (SOV), and the diploic channels of the greater wing of the sphenoid bone (DCGW). The CS type was the most frequently identified, followed by the SOV and DCGW types. In dissected specimens, the LVs consistently coursed between the posterior margin of the LG and the superolateral part of the CS, above the upper margin of the lateral rectus muscle.

CONCLUSIONS

The LV may consistently emerge from the upper posterior margin of the LG. It commonly pours into the SOV or superolateral part of the CS.

Radiological Determinants of Complicated Immunoglobulin G4-Related Ophthalmic Disease: A Territory-Wide Cohort Study

PURPOSE

To evaluate the presenting radiological features of immunoglobulin G4-related ophthalmic disease (IgG4-ROD) and their associations with IgG4-related optic neuropathy (IgG4-RON), and IgG4-related ocular adnexal lymphoma (IgG4-ROL).

METHODS

A territory-wide, biopsy-proven, Chinese cohort. Masked review of orbital images, medical records, and histopathology reports.

RESULTS

A total of 115 (94%) of the 122 patients in our cohort had preoperative orbital images (computed tomography=105, magnetic resonance imaging=40). Among them, 103/115 (90%) showed enlarged lacrimal glands, and 91 (88%) were bilateral. Nerve enlargement was observed: infraorbital in 31/115 (27%) patients and frontal in 17/115 (15%), 10 and 9 being bilateral, respectively. At least 1 or more extraocular muscle (EOM) enlargement was found in 41/115 (37%) patients, bilaterally in 20. Lateral rectus occurred in 30 (73%) of these 41 EOM patients and inferior rectus in 28 (68%). Two adjacent EOMs (inferior and lateral recti in 11 patients, inferior and medial recti in 7 patients) or multiple EOMs (at least 3) were enlarged in 23/41 (56%) and 13/41 (32%) of the patients, respectively. Intraconal lesions (67% vs 11%, P<0.05), infraorbital (83% vs 23%, P<0.005), or frontal (50% vs 15%, P<0.05) nerve enlargement was significantly associated with IgG4-RON (6 patients) by univariate analyses. Asymmetric lacrimal gland enlargement and discrete orbital mass (both P<0.05) were associated with IgG4-ROL (9 patients) by multivariate analyses.

CONCLUSIONS

In this IgG4-ROD cohort, most patients had bilateral enlarged lacrimal glands, and the lateral rectus is the most frequently involved EOM. For the first time, unique radiological patterns associated with the development of IgG4-RON and IgG4-ROL are found.

Lacrimal gland regeneration: The unmet challenges and promise for dry eye therapy

DED (Dry eye disease) is a common multifactorial disease of the ocular surface and the tear film. DED has gained attention globally, with millions of people affected.. Although treatment strategies for DED have shifted towards Tear Film Oriented Therapy (TFOT), all the existing strategies fall under standard palliative care when addressed as a long-term goal. Therefore, different approaches have been explored by various groups to uncover alternative treatment strategies that can contribute to a full regeneration of the damaged lacrimal gland. For this, multiple groups have investigated the role of lacrimal gland (LG) cells in DED based on their regenerating, homing, and differentiating capabilities. In this review, we discuss in detail therapeutic mechanisms and regenerative strategies that can potentially be applied for lacrimal gland regeneration as well as their therapeutic applications. This review mainly focuses on Aqueous Deficiency Dry Eye Disease (ADDE) caused by lacrimal gland dysfunction and possible future treatment strategies. The current key findings from cell and tissue-based regenerative therapy modalities that could be utilised to achieve lacrimal gland tissue regeneration are summarized. In addition, this review summarises the available literature from in vitro to in vivo animal studies, their limitations in relation to lacrimal gland regeneration and the possible clinical applications. Finally, current issues and unmet needs of cell-based therapies in providing complete lacrimal gland tissue regeneration are discussed.

Correlation between extent of lacrimal gland prolapse and clinical features of thyroid-associated ophthalmopathy: a retrospective observational study

Background

Studies on the factors related to lacrimal gland prolapse (LGP) in patients with thyroid-associated ophthalmopathy (TAO) are limited. This study aimed to assess the factors associated with LGP on magnetic resonance imaging (MRI) and its relation to TAO activity .

Methods

Thirty-six patients (72 orbits) with inactive TAO (43 orbits, Clinical Activity Score [CAS] < 3) or active TAO (29 orbits, CAS ≥3) were investigated retrospectively. All patients underwent ophthalmic evaluation and orbital magnetic resonance imaging. The severity of LGP and proptosis and the extraocular muscle (EOM) volume were measured. LGP and related factors were assessed by correlational and linear regression analyses. The value of LGP for discriminating the activity of TAO was evaluated by receiver-operating characteristic curve analysis.

Results

The mean LGP was significantly higher in the active TAO group than in the inactive TAO group (P < 0.001). There were significant positive correlations between LGP severity and the CAS (r = 0.51, P < 0.001), proptosis (r = 0.72, P < 0.001), and EOM volume (superior rectus [r = 0.49, P < 0.001], inferior rectus [r = 0.47, P < 0.001], lateral rectus [r = 0.59, P < 0.001], medial rectus [r = 0.62, P < 0.001], superior oblique [r = 0.48, P < 0.001], and all EOMs [r = 0.59, P < 0.001]). Receiver-operating characteristic curve analysis revealed an LGP of 13.65 mm (area under the curve, 0.824; sensitivity, 79.3%; specificity, 81.4%) to be the cut-off value that differentiated active and inactive TAO.

Conclusions

LGP measurements obtained from orbital magnetic resonance images were positively correlated with CAS, proptosis and EOM volume. The extent of LGP appears to be a good indicator of disease activity in patients with TAO.

The value of SPECT/CT imaging of lacrimal glands as a means of assessing the activity of Graves' orbitopathy

BACKGROUND

Graves' orbitopathy (GO) is an autoimmune disease with mechanical impairment of orbital muscles and lacrimal gland dysfunction. The frequently used methods of assessing GO activity include Clinical Activity Score (CAS), CT, and MRI. These approaches are mainly associated with orbital muscles; however, there are not many studies that focus on the lacrimal gland inflammation of GO patients.

OBJECTIVE

The aim of this study is to assess the usefulness of 99mTc-DTPA single-photon emission (SPE) CT/CT in evaluating the lacrimal gland inflammation in GO, as compared with other methods.

METHODS

A retrospective analysis of 48 patients with active GO compared with 33 controls was conducted. All subjects underwent clinical-endocrinological analyses, CAS evaluation, CT scans, and SPECT/CT examination. Lacrimal gland dimensions were determined and analyzed.

RESULTS

The lacrimal glands in patients with GO were significantly larger in all measured dimensions (P < 0.001) on CT scans relative to those in controls. Increased lacrimal gland diethylene triamine pentaacetic acid (DTPA) uptake ratios (P < 0.001) were displayed in active GO patients compared to controls and were also correlated with thyrotropin receptor antibody levels. The cut-off value for discriminating active and inactive disease was calculated to be 1.735, with specificity of 82.6% and sensitivity of 74.2%. SPECT/CT uptake ratios and CAS values were positively correlated in all GO patients. SPECT/CT uptake ratios were also positively correlated with CT measurements including lacrimal gland volume and coronal width in GO patients.

CONCLUSIONS

These data indicated that lacrimal gland SPECT/CT images can serve as a good tool for assessing the inflammation and disease activity of GO.

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.

Computed Tomography Evaluation of Normal Lacrimal Gland Dimensions in the Adult Pakistani Population

Objectives To estimate the normal dimensions of lacrimal glands (LGs) in the Pakistani population using computed tomography (CT) scan and to determine the associations of LG dimensions with age, sex, and laterality. Methods The study population included subjects aged ≥16 years without orbital pathology who underwent CT evaluation of both the right and left LGs at Dr. Ziauddin University Hospital from June 2018 to November 2019. The mean axial length (AL), axial width (AW), coronal length (CL), and coronal width (CW) of each LG were measured separately. Results The 108 subjects enrolled in this study included 75 (69.4%) men and 33 (30.6%) women, with a mean age of 49±20 years. Right and left LG dimensions were similar, including mean AL (13.53±1.80 mm vs. 13.35±1.72 mm), mean AW (4.20±0.81 mm vs. 4.05±0.93 mm), mean CL (15.46±1.97 mm vs. 15.26±1.87 mm), and mean CW (3.99±0.80 mm vs. 3.86±0.81 mm). The AL of both LGs and the CL and CW of right but not left LGs were significantly lower in women than in men. Age showed significant correlations with the AL and CL of both LGs. Conclusion These findings establish the normal range of LG dimensions in adult Pakistani populations. Some LG dimensions are smaller in women than in men, as well as correlating with age.

Lacrimal Gland Changes on Orbital Imaging after Glaucoma Drainage Implant Surgery

PURPOSE

This study evaluates the radiographic appearance of lacrimal gland tissue after placement of a glaucoma drainage implant (GDI) to characterize the impact of the device on the gland's imaging patterns.

METHODS

We performed retrospective chart review of departmental records at two urban academic medical centers, which were systematically searched using procedure codes to identify adult glaucoma patients who underwent unilateral superotemporal GDI from January 1995 to December 2015. Radiology records were cross-checked to identify the subset of patients who underwent postoperative orbital CT or MRI. Chart review collected data on glaucoma diagnosis, management, examination findings, and clinical complaints. Imaging studies were reviewed for orbital changes using qualitative assessment of the radiographic appearances and computer-guided calculations to quantify asymmetries.

RESULTS

A review of all eye operations in the inclusion period identified 315 patients with GDI, 13 of whom were eligible for inclusion. Elapsed time from device placement to imaging averaged 41.9 months, and the average clinical follow-up was 56.4 months. Radiographic lacrimal gland changes were appreciable in 69% (9 of 13) of patients, most commonly with posterior displacement and flattening of the gland (7 of 13). ImageJ analysis revealed significantly smaller lacrimal glands in orbits with GDI (P = 0.04). No clear correlation was found between gland changes and clinical dry eye symptoms.

CONCLUSION

GDI placement was associated with radiographically-appreciable lacrimal gland changes in two-thirds of patients, with changes occurring in a predictable pattern of lacrimal gland flattening, posteriorization, and volume loss. Radiographic changes correlated with clinical symptoms in few patients.

Risk of dry eye syndrome in patients treated with whole-brain radiotherapy

With improvements in systemic therapy, patients with cancer treated with whole-brain radiotherapy (WBRT) are living long enough to develop late toxicities, including dry eye syndrome. In general practice, dose to the lacrimal gland (LG) is not constrained (maximum constraint <40 Gy) in WBRT. The purpose of this study was to measure dose to the LG in WBRT and determine methods for reducing radiation exposure. We conducted a retrospective review of 70 3-dimensional (3D) conformal plans; thirty-six plans with a radiation prescription of 30 Gy in 10 fractions and 34 plans with a prescription of 37.5 Gy in 15 fractions. LGs were contoured in accordance with Freedman and Sidani (2015). Biological effective dose (BED)3 maximum constraints were calculated from 40 Gy and 20 Gy to be 32.17 Gy (30 Gy) and 36.70 Gy (37.5 Gy). Both regimens demonstrated supraorbital blocking by 3 methods: T1, bordering the supraorbital ridge; T2, no contact with supraorbital ridge; and T3, coverage of the supraorbital ridge. Mean dose for the plans with a 30-Gy prescription and the plans with a 37.5-Gy prescription was 27.5 Gy and 35.2 Gy, respectively (p ≤ 0.0001). BED3 maximum constraint (D_max) was violated 16 of 26 (61.5%) in T1 (average D_max: 32.2 Gy), 13 of 28 (46.4%) in T2 (average D_max: 32.1 Gy), and 5 of 18 (27.8%) in T3 (average D_max: 31.8 Gy) for the 30-Gy prescription. D_max was violated in 32 of 32 (100%) in T1 (average D_max: 40.1 Gy), 22 of 22 (100%) in T2 (average D_max: 40.3 Gy), and 14 of 14 (100%) in T3 (average D_max: 39.4) for the 37.5 Gy prescription. Average D_max for the 37.5-Gy prescription was highly significant in favor of T3 (p = 0.0098). Patients who receive WBRT may develop dry eye syndrome as a late toxicity. Constraints are commonly violated with a prescription of 37.5 Gy. Methods to reduce dose include T3 supraorbital blocking, an easily implementable change that may dramatically improve patient quality of life.

Evaluation of Lacrimal Gland Dimensions and Volume in Turkish Population with Computed Tomography

INTRODUCTION

Computed tomography (CT) is a widespread method for evaluating head and neck pathologies. The lacrimal glands (LGs) are usually visible in routine head and neck CT scans. LG pathologies usually manifests with changes in gland sizes, so it is important to know the normal values of the LG dimensions and volume. The LG sizes may change with age, gender and race. The normal values of LG dimensions and volume in Turkish population was not reported before.

AIM

The aim of this study was to evaluate the dimensions and volumes of the LGs by CT in a Turkish population.

MATERIALS AND METHODS

Two hundred seventeen consecutive paranasal CT scans of subjects evaluated retrospectively. Measurements of LG dimensions were performed in axial and coronal paranasal CT images. The LG volume was calculated with Aquarius software by outlining the gland in all consecutive axial images.

RESULTS

Four hundred orbits of 200 subjects were included to the study. The mean axial LG length in right and left orbits were 16.2±2.0 mm and 16.0±2.0 mm and the mean axial width of the right and left orbits were 4.1±0.7 mm and 4.0±0.7 mm. The right and left LG mean values for coronal length and width were equal 18.3 ±2.2 mm and 4.1±0.7mm respectively. The mean LG volume was 0.617±0.210 cm(3) in right and 0.597±0.197 cm(3) in the left orbits. There were statistically significant differences in the axial width and volume of the LG according to sides, however there was no significant difference according to gender. Age and LG measurements were negatively correlated.

CONCLUSION

Our study may serve as a guide to determine the average values of the LG measurements in Turkish population and find out the orbital pathologies that involves the LG.

Age, gender, and interracial variability of normal lacrimal gland volume using MRI

PURPOSE

Aimed to evaluate normal volume of the lacrimal gland in patients of different age groups and race.

METHODS

All MRI studies of the brain that were done between June 2012 and April 2013 were examined. Lacrimal glands were identified using fat-saturated fluid-attenuated inversion recovery (FLAIR) images, and the volumes were calculated using TeraRecon iNtuition viewer. Volumes for the right and left lacrimal glands were recorded for persons of different age groups and race, and the results were compared with those of a randomly selected group of patients who had undergone the same calculation method using CT of the brain, orbit, or paranasal sinuses.

RESULTS

The authors included 998 lacrimal glands of 499 patients. The mean volumes for the right and left lacrimal glands were 0.770 and 0.684 cm, respectively. Lacrimal glands were larger in women; the largest volumes were observed during the second decade of life. Mean volumes also varied with race: 0.840 cm in Asians, 0.790 cm in Africans, 0.760 cm in Indians, and 0.710 cm in Middle Easterners. The consultant neuroradiologist and the intern showed excellent agreement for measurements of lacrimal gland volume. No significant difference was observed between lacrimal gland measurements method on MRI and CT.

CONCLUSION

Lacrimal gland volume varies according to age, gender, race, and laterality. Measurements with MRI using fat-saturated FLAIR images and TeraRecon iNtuition viewer software are reliable, accurate, and can be used by junior staff with less radiation exposure to patients.