[Exophthalmometry and thyroid disease. The value of the Hertel measurement evaluated by a group of patients with thyroid diseases and a control group].

Exophthalmometry values from routine referrals to a hospital eye clinic are analysed, including adult patients with and without thyroid disease. In thyroid disease without eye motility complaints (n = 90) the median exophthalmometry value was 18 mm (range 12-28 mm). Thyroid patients with eye muscle involvement (diplopia, n = 47) had significantly higher values (median 22 mm, range 15-31 mm) but did not differ significantly from a subgroup of 51 patients without thyroid disease, but with "big eyes" as a (presumably) physiological finding (median value 20 mm, range 16-25 mm). The above three categories were all excluded from the control group (n = 203) which had 16 mm as median value, range 11-23 mm. Mean values were 16.0 +/- 1.8 mm in the females and 16.5 +/- 2.3 mm in the male controls. A side difference in exophthalmometry value > or = 2 mm appeared in 34% of thyroid patients with eye muscle involvement. This appeared in only a few per cent in the three other groups. Due to the wide overlap between groups, the solitary exophthalmometry reading is of limited diagnostic value, while the importance of exophthalmometry is evident when following the individual patient with orbital disease.