At 4 years after thyroid eye disease (TED) diagnosis, patients are twice as likely to develop strabismus and more likely to undergo strabismus surgery than to have orbital decompression surgery, according to a study published in JAMA Ophthalmology.
Researchers conducted a Danish nationwide registry-based cohort study between January 1, 2000 and December 31, 2018. The cohort comprised a mean 4.3 million people aged 18 to 100 years with no previous TED diagnosis each year. The total examination time was 8.22 × 107 person-years (women, 4.18 × 107 person-years; men, 4.04 × 107 person-years).
The main study outcome measures were the annual numeric and age-standardized incidence of hospital-treated TED and cumulative incidence of strabismus, strabismus surgery, and orbital decompression surgery among patients with TED. The team stratified the incidence by sex, thyroid diagnosis, and age.
Researchers identified 4106 incident diagnoses of TED during 19 years in 3344 women (81.4%) and 762 men (18.6%). The mean annual nationwide incidence rate of TED was 5.0 per 100 000 person-years overall, 8.0 per 100,000 person-years in women, and 1.9 per 100,000 person-years in men, indicating that women developed TED approximately 4 times more often than men. The team notes that the age-standardized incidences were similar. The mean age at onset was 51.3±14.5 years overall, 51.1±14.5 years in women, and 52.2±14.5 years in men, according to the report.
At the time of TED diagnosis, 611 patients (14.9%) had euthyroid, 477 (11.6%) had hypothyroid, and 3018 (73.5%) had hyperthyroid. In patients with TED who were euthyroid, the 4-year cumulative incidence for redeeming a prescription was 41% for antithyroid medication and 13% for L-thyroxine.
In patients with TED, the 4-year cumulative incidence for strabismus was 10%, while the 4-year cumulative incidence of surgical interventions was 8% for strabismus surgery and 5% for orbital decompression. At 4 years, strabismus surgery was more frequent among men (13.3%; 95% CI, 10.75-15.86) compared with women (7.2%; 95% CI, 6.24-8.08), and the absolute difference was 6.1% (95% CI, 3.42-8.14; P <.001). The researchers reported that women and men were equally likely to have orbital decompression surgery.
Limitations of the study include the registry-based design, inability to estimate procedures performed outside of the hospitals, and these results are only generalizable to populations with comparable ethnicity, iodine intake status, and health care access.
“Our results provide empirical clinical data on TED and should be used to inform patients and implement preventive health care strategies,” according to the researchers.
Boulakh L, Nygaard B, Bek T, et al. Nationwide incidence of thyroid eye disease and cumulative incidence of strabismus and surgical interventions in Denmark. JAMA Ophthalmol. Published online May 19, 2022. doi:10.1001/jamaophthalmol.2022.1002