High levels of thyroid-stimulating hormone receptor antibody (TRAb) and thyroid-stimulating immunoglobulin (TSI) are significant preoperative risk factors for recurrence of proptosis after orbital decompression in patients with Graves orbitopathy (GO), according to research published in the American Journal of Ophthalmology. TRAb may serve as a presurgical screening biomarker to help surgeons determine the best time to perform orbital surgery, according to the report.
Researchers retrospectively reviewed 217 patients with GO who underwent rehabilitative orbital decompression for disfiguring proptosis in an inactive state with a low clinical activity score (0-2) from January 2017 to December 2020 by a single surgeon. They measured exophthalmos using a Hertel exophthalmometer.
The study defined proptosis recurrence as an increase of 2 mm or more following decompression during the follow-up period. The research team analyzed the association between preoperative variables and proptosis recurrence using multivariable logistic regression.
The researchers found that 11 patients (5.1%) experienced recurrence of proptosis during the follow-up period (mean follow-up, 15.6 months; range, 3-30 months).
In the univariate logistic regression analysis, TRAb and TSI were significant factors for proptosis recurrence. Age, sex, smoking, disease duration, orbital radiotherapy, and total thyroidectomy history were non-significant factors for recurrence.
The multivariate logistic regression analysis showed that TRAb remained a significant factor for proptosis recurrence (OR 1.06; P =.014). Receiver operating characteristic (ROC) curve analysis showed an area under curve 0.86 with a sensitivity 90.9% and specificity 82.0% at TRAb level 7.96 IU/L.
“In conclusion, this study shows that high levels of TRAb and TSI are significant risk factors for the recurrence of proptosis after orbital decompression,” according to the researchers. “In this study, we propose that presurgical screening biomarkers, with appropriate cut-off values, may assist surgeons in determining the optimal timing of orbital surgery. Compared to TSI, TRAb is more practical given its availability and time- and cost-effectiveness.”
Study limitations include its retrospective nature, single center design, and the relatively short follow-up period.
Byeon HJ, Ko J, Kikkawa DO, Yoon JS. Preoperative risk factors for proptosis recurrence after rehabilitative orbital decompression in Graves’ orbitopathy patients. Am J Ophthalmol. Published online August 3, 2023. doi:10.1016/j.ajo.2023.07.020