Echographic characterization of extraocular muscles in pediatric patients with thyroid dysfunction.

PURPOSE: To characterize the size of extraocular muscles (EOMs) in a pediatric population with thyroid dysfunction using orbital echography. METHODS: Patients under age 18 with thyroid dysfunction who presented to an academic ophthalmology department from 2009 to 2020 and received orbital echography were included in this IRB-approved retrospective study. Data collected included age, clinical activity score (CAS), thyroid stimulating immunoglobulin (TSI), and extraocular recti muscle thickness on echography. Patients were organized into three age cohorts, after which statistical analysis compared recti measurements to previously reported normal ranges. RESULTS: Twenty patients with thyroid dysfunction were included. When comparing average recti muscle thicknesses of study patients to those of previously published normal children in similar age ranges, the levator-superior rectus complex was significantly increased in all age groups of children with thyroid dysfunction (p-values = <.004), and the levator-superior rectus complex was most frequently enlarged compared to published normal values (78% of eyes). CAS was not correlated with EOM size in the youngest group (5-10 years old, p-values >.315) but was significantly correlated in older groups (11-17 years old, p-values <.027). TSI was not correlated with EOM size in any group (p-values >.206). CONCLUSIONS: Echographic reference ranges for EOMs in children with thyroid dysfunction were established. There are increased rates of levator-superior rectus complex enlargement in children with TED compared to adults with TED, and EOM size is correlated with CAS in children older than 10 years. Though limited, these findings may serve as an additional tool for ophthalmologists to ascertain disease activity in pediatric patients with thyroid dysfunction.

Echographic Assessment of Extraocular Muscle Response to Teprotumumab.

PURPOSE: To evaluate extraocular muscle response to teprotumumab using orbital echography in thyroid eye disease. METHODS: This retrospective study included adult thyroid eye disease patients with pre- and post-teprotumumab orbital echography. Data collected included: age, Hertel measurements, clinical activity score, Gorman diplopia scores, ocular motility, and recti muscle diameters measured by echography. The patient's more proptotic eye before treatment initiation was designated as the study orbit. Ocular motility was assessed by totaling the ductions in all 4 cardinal directions. Orbital echography was obtained pre- and post-treatment to assess response of extraocular muscle diameters. RESULTS: Six patients with a mean age of 67 years were included. There was a mean improvement in proptosis of 4.3 mm in the study eye with 11/12 orbits showing improvement in globe position ( p < 0.05). All patients had a decrease in clinical activity score with a mean reduction of 2.5. Four patients had an improvement in Gorman diplopia score. Ocular motility in the study orbits improved by a total mean of 26.9° ( p < 0.05). Mean total extraocular muscle diameter was reduced from 27.4 to 23.4 mm ( p < 0.001). On average, superior recti were largest pre- and post-treatment, followed by inferior, medial, then lateral recti. However, inferior recti showed the greatest reduction of 23% ( p < 0.02). CONCLUSIONS: Orbital echography demonstrated extraocular muscle reduction in all patients after teprotumumab, correlating with improved clinical activity score, ocular motility, and proptosis. Orbital echography is a safe and cost-effective imaging alternative to monitor therapeutic response to teprotumumab.