Relationship between thyroid state and eye disease assessed by orbital ultrasonography in patients with Graves' disease

ABSTRACT

The present study included twenty patients with untreated Graves' disease [GD] with or without Graves' ophthalmopathy [GO] graded according to a clinical eye score [NOSPECS classification] and twenty normal subjects. Extraocular muscle [EOM] involvement [class VI] was clinically apparent in 25% of patients with GD, while orbital ultrasonography detected thickening of one or more EOM in 80% of patients including those with no or early clinical eye disease [class O or I]. In a descending order of frequency, the medial [MR], inferior [IR], superior [SR], and lateral [LR] rectus muscles were thickened. The progression of clinically apparent GO had a positive correlation only with the duration of eye disease and the thickening of SR muscle and of retrobulbar fat [RBF]. Considering thyroid state, overt hyperthyroidism was documented in 16 patients [80%] with GD and most of them had evidence of a concomitant [mostly subclinical] eye disease. On the other hand, 75% of patients with GO detected by ultrasonography demonstrated some abnormality in thyroid function. Although GO was strongly associated with Graves' hyperthyroidism, yet, no definite correlation has been observed between serum levels of thyroid hormones and severity of GO suggesting that the course of ophthalmopathy is independent of the thyroid function. On the basis of the present work, a close liaison between the physician and the ophthalmologist is important for early detection and treatment of eye disease in patients with GD before marked damage to EOM occurs. Orbital ultrasonography is a sensitive, safe and easy technique for screening the presence, but not the severity of GO. Being the most frequent and earliest to be involved and the easiest to measure, the MR muscle could be chosen for ultrasonographic examination in patients with GD