Comparison of a diplopia questionnaire to the Goldmann diplopia field

Purpose: To compare diplopia scores obtained with a new diplopia questionnaire to the established Goldmann diplopia field. Methods: Seventy-five consecutive patients with binocular diplopia associated with any type of strabismus were assessed with the diplopia questionnaire and the Goldmann perimeter. Diplopia was scored, according to published protocols, from 0 to 100, where 0 is no diplopia and 100 is diplopia in all measured positions. Where there was a discrepancy of more than 20 points between the Goldmann diplopia field and the diplopia questionnaire, two observers classified the reasons for the discrepancy. Results: There was fair overall agreement between the diplopia questionnaire and the Goldmann diplopia field, with 44 (59%) of 75 patients having agreement within 20 points (intraclass correlation coefficient 0.53, 95% CI 0.35-0.68). Of the 31 (41%) of 75 patients who had a discrepancy of more than 20 points, 13 (42%) of 31 exhibited a higher diplopia score with the diplopia questionnaire than the Goldmann perimeter, and 18 (58%) of 31 showed a higher diplopia score with the Goldmann diplopia field than the questionnaire. The most frequent reason for a higher diplopia questionnaire score was the proximal test distance of the Goldmann diplopia field (6 of 13 cases). The most frequent reason for a higher Goldmann diplopia field score appeared to be patient adaptation to diplopia (9 of 18 cases). Conclusions: The diplopia questionnaire may better represent binocular diplopia in everyday life than the Goldmann perimeter, capturing adaptation to diplopia, suppression, fragile fusion, and diplopia with distance fixation.