Double vision is a major manifestation in moderate to severe Graves' orbitopathy, but It correlates negatively with inflammatory signs and proptosis

Context: Double vision (diplopia) is a major determinant of work disability in patients with Graves' orbitopathy (GO), but it is not part of the NOSPECS classification of GO. Objective: To quantitate diplopia in patients with moderate to severe GO, and to study associations with other disease and patient variables. Design: Single center prospective study of consecutive patients at the time of referral. Setting: University Hospital Thyroid-Eye-Clinic. Patients: 216 patients diagnosed with moderate to severe and active GO. Main Outcome Measures: Binocular diplopia in field of gaze, and monocular fields of motility were prospectively recorded on diagrams and measured by planimetry. Fields of diplopia were correlated to other disease and patient variables. Results: Six patients had only one functional eye and were excluded. Among the remaining 210 patients, diplopia was present in 75.2 %. In patients with diplopia this ranged from five to 100 % (observed in 11.4 % of patients) of binocular field of gaze. The field of diplopia correlated positively with eye motility restriction and with asymmetrical affection of orbits but negatively with signs of inflammation and proptosis that often are the main outcome measures in clinical studies of GO therapy. Conclusion: Diplopia is very common in moderate to severe GO and a major cause for active therapy. In moderate to severe GO the field of diplopia correlates negatively with some other indicators of disease activity, which may be explained by the physiological properties of binocular fusion.