Comparison of cyclodeviation and duction measurement in Graves' orbitopathy patients using different devices

To compare measurement outcomes of different devices measuring cyclodeviation and ductions in Graves' orbitopathy (GO) patients. Cyclodeviation in GO patients was measured using the Harms tangent screen (HTS), the cycloforometer of Franceschetti, and the synoptometer. Ductions were measured using the modified perimeter, the Goldmann perimeter and the Maddox tangent scale (MTS). In 13 patients, cyclodeviation in primary position, up-, and downgaze was measured with the above-mentioned devices. The mean differences ranged from 0.3º to 3.1º and were smallest between the HTS and the cycloforometer (89% of all measurements within 2º difference). Measurement of abduction, adduction, elevation, and depression using the modified perimeter, Goldmann perimeter, and MTS were obtained in another 13 patients. The mean differences ranged from 1.2º to 12.9º and were smallest between the modified perimeter and the Goldmann perimeter (92% of all measurements ≤ 8º). The HTS and cycloforometer produce interchangeable measurement outcomes. The modified perimeter and the Goldmann perimeter are interchangeable as well. However, the synoptometer and the MTS are not suitable for comparative analysis