Age and Clinical Activity Score (CAS): Key Predictive Factors for Non-shrinking Extraocular Muscles in Graves'...

To identify predictive factors for non-shrinking extraocular muscles (EOMs) after retrobulbar injection of glucocorticoids (GCs) in patients with Graves' ophthalmopathy (GO).

This retrospective cohort study included 60 GO patients (102 eyes) who received retrobulbar GC injections. We used univariate analysis, Least Absolute Shrinkage and Selection Operator (LASSO) regression, and multivariate logistic regression to identify factors associated with non-shrinking EOMs. The primary outcome was the change in EOM volume assessed by orbital computed tomography (CT) scans before and after treatment.

After retrobulbar injection of GCs, 36 eyes (35.3%) showed a reduction in EOM volume, while 66 eyes (64.7%) did not. Multivariate analysis revealed that age (OR = 1.09, 95% CI: 1.01-1.18, p = 0.03) and Clinical Activity Score (CAS)≥3 (OR = 0.11, 95% CI: 0.02-0.59, p = 0.008) were independent predictors of non-shrinking EOMs. Higher age increased the odds of non-shrinking EOMs by 9% per year, while higher disease activity (CAS≥3) was associated with a better treatment response. Other factors, like proptosis and axial orbit depth, showed trends but did not reach statistical significance.

Age and disease activity (CAS≥3) are significant predictors of non-shrinking EOMs after retrobulbar GCs injection in GO patients. These findings can help clinicians better assess treatment outcomes and optimize therapeutic strategies for GO patients. Future research should focus on expanding the sample size and exploring underlying biological mechanisms to further validate these findings and improve treatment precision.