This is the first study to report the range of normal volume for Caucasian lacrimal glands measured on CT scans. The volume of the lacrimal gland decreases with age, and there is no gender or laterality difference.

This study is the first to report the volume of the lacrimal gland calculated on CT scan for patients with TED. The lacrimal gland is larger in patients with TED and correlates with subjective tearing and exophthalmometry.

Purpose Identify a reproducible measure of axial globe position (AGP) for multicenter studies of patients with thyroid eye disease (TED). Methods This is a prospective, international, multicenter, observational study in which 3 types of AGP evaluation were examined: radiologic, clinical, and photographic. In this study, computed tomography (CT) was the modality to which all other methods were compared. CT AGP was measured from an orthogonal line between the anterior lateral orbital rims to the cornea. All CT measurements were made at a single institution by 3 individual clinicians. Clinical evaluation was performed with exophthalmometry. Three clinicians from each clinical site assessed AGP with 3 different exophthalmometers and horizontal palpebral width using a ruler. Each physician made 3 separate measurements with each type of exophthalmometer, not in succession. All photographic measurements were made at a single institution. AGP was measured from lateral photographs in which a standard marker was placed at the anterior lateral orbital rim. Horizontal and vertical palpebral fissure were measured from frontal photographs. Three trained readers measured 3 separate times, not in succession. Exophthalmometry and photography method validity was assessed by agreement with CT (mean differences calculation, ICC’s, Bland-Altman figures). Correlation between palpebral fissure and CT AGP was assessed with Pearson correlation. Intraclinician and interclinician reliability was evaluated using intraclass correlation coefficients (ICC). Results Sixty-eight patients from 7 centers participated. CT mean AGP was 21.37mm (15.96 – 28.90mm) right, 21.22mm (15.87 – 28.70mm) left (ICC 0.996 and 0.995). Exophthalmometry AGP fell between 18mm and 25mm. Intraclinician agreement across exophthalmometers was ideal (ICC 0.948 – 0.983). Agreement between clinicians was greater than 0.85 for all upright exophthalmometry measurements. Photographic mean AGP was 20.47mm (10.92 – 30.88mm) right, 20.30mm (8.61 – 28.72mm) left. Intrareader and interreader agreement was ideal (ICC 0.991 – 0.989). All exophthalmometers’ mean differences from CT ranged between −0.06mm (+/− 1.36mm) and 0.54mm (+/− 1.61mm); 95% CI fell within 1mm. Magnitude of AGP did not affect exophthalmometry validity. Oculus best estimated CT AGP but differences form other exophthalmometers were not clinically meaningful in upright measurements. Photographic AGP (right ICC=0.575, left ICC=0.355) and palpebral fissure do not agree with CT. Conclusions Upright clinical exophthalmometry accurately estimates CT AGP in TED. AGP measurement was reliably reproduced by the same clinician and between clinicians at multiple institutions using the protocol in this study. These findings allow reliable measurement of AGP that will be of considerable value in future outcome studies.

Transcranial decompression is an effective and safe method of salvaging vision when standard treatments fail. This is only the second report of transcranial decompression for refractory compressive optic neuropathy after decompression from a standard approach.