Past research has found that lacrimal gland (LG) enlargement can occur in thyroid eye disease (TED) secondary to antibody-mediated inflammation. However, studies specifically quantified LG volume in TED patients with compressive optic neuropathy (CON) and compared to those TED patients without CON are lacking. In a trial presented at ASOPRS 2021, results demonstrated a statistically significant increase in LG volume in TED patients with CON when compared to TED controls. LG volume correlated positively with extraocular dysmotility.

The trial evaluated patients with TED treated at a single center who underwent orbital CT imaging who patients were classified as TED-CON based on a combination of decreased visual acuity, visual field deficit, dyschromatopsia, or an afferent pupillary defect. Extraocular dysmotility was recorded as a summation of motility restriction (0 to -4) in the four cardinal gaze directions. LGs were contoured in a series of axial cuts, in line with the methodology described by Freedman et al. 1 Measurement of LG volumes was provided by an automated dose-volume histogram calculation based on the contoured outline.

Researchers compared two-sample t-test using Pearson’s correlation to determine the relationship between LG volume and clinical characteristics including visual acuity, color vision, dysmotility and Hertel exophthalmos.

Fifty-two patients (104 orbits) with TED-CON and 22 patients (44 orbits) with TED and no evidence of CON were reviewed. The differences in LogMAR visual acuity (0.24 vs. 0.12, p = 0.028), color vision (4.1 vs 5.1 out of 6 plates, p = 0.019), Hertel’s exophthalmos (25.1 vs. 23.7 mm, p = 0.047) and extraocular dysmotility (-4.3 vs. -0.8, p < 0.001) between groups were statistically significant (Table 1).

Mean LG volume in cm3 was 0.939 ± 0.372 for TED-CON and 0.644 ± 0.317 for TED controls (p < 0.001). A statistically significant correlation was seen in the combined TED-CON and control study population between LG volume and extraocular dysmotility (r = 0.205, p = 0.031).

Although previous studies that used both two-dimensional and three-dimensional contouring techniques found a significant increase in LG volume in patients with TED when compared to normal controls, the presented study . The present study found a statistically significant increase in LG volume in TED patients with CON when compared to TED controls. LG volume correlated positively with extraocular dysmotility. These findings suggest that despite the LG’s anterior location, radiographic enlargement of the LG represents a risk factor for the presence of CON.

 

North VS, Nanda T, Tran AQ, et al. Lacrimal Gland Enlargement Is a Risk Factor for Thyroid Eye Disease-Compressive Optic Neuropathy
Presented at: ASOPRS Fall Scientific Symposium; November 11-12, 2021; New Orleans, LA.
https://asoprsfall.virtualbyvario.com/wp-content/uploads/2021/10/ASOPRS_2021_fall_syllabus_FINAL.pdf

 

Source:

  1. Freedman L, Sidani C. A radiation oncologist’s guide to contouring the lacrimal gland. Practical radiation oncology. 2015 Nov 1;5(6):e697-8.