To the Editor.
—In a recent report entitled "Ultrasound in Early Thyroid Orbitopathy" (Archives 1980;98:277-279), Shammas et al measured the optic nerves of seven mildly exophthalmic eyes. Contrasting their findings with my previous report1 detailing an invariable increase in the subdural perineural space in 30 patients (55 eyes) with endocrine orbitopathy, they found no nerves to be "thickened abnormally," all neural-dural diameter differences being less than 2 mm.As I reported the upper limit of normal for optic nerve neural-dural diameter differences to be 1.50 mm2 (and not 2 mm), with a mean diameter difference of only 2.03 mm1 in patients with extraocular muscles enlarged beyond the 95th percentile of the normal population, the conclusion that "enlarged optic nerves" (?) are "not always present" in the early stages of Graves' disease cannot be drawn from the data presented in this article (assuming that by enlarged optic nerves these
Skalka H. Ultrasound in Orbitopathy. Arch Ophthalmol. 1980;98(12):2244-2245. doi:10.1001/archopht.1980.01020041096025