Grading soft tissue metrics in thyroid eye disease

Investigators compared the reliability of 3 scales for assessing soft tissue inflammatory and congestive signs associated with thyroid eye disease.

Study design

This prospective observational study included 55 adults with thyroid eye disease (TED) who were seen at 9 international centers. Six signs of TED were assessed using 3 commonly used scales: presence/absence scale; 0–2 scale and percentage scale. Each sign was measured by an experienced orbital surgeon and a trainee. A high level of agreement was defined as 0.7 or better.

Outcomes

The presence/absence and 0–2 scales demonstrated good agreement between graders, but the percentage scale did not. Interrater reliability scores showed high reliability for both presence/absence and 0–2 scales only for bulbar conjunctival edema and eyelid edema. The presence/absence scale also showed high interrater reliability for bulbar conjunctival redness and eyelid redness. No scale showed high interrater reliability for superior conjunctival redness or caruncular edema.

Limitations

Strengthening inclusion criteria to a shorter period of time from diagnosis of TED would have captured more change in measurements; this study used 9 months which is admittedly challenging. A larger sample size would have improved the study.

Clinical significance

The percentage scale does not seem valuable for assessing redness and edema of the eyelid conjunctiva or caruncle in TED. Cruder scales such as presence/absence and a 0–2 scale appear more accurate, but even so, no scale reliably rated redness and edema of all periocular structures in TED. Researchers should continue to develop and test other grading systems for thyroid eye disease.