Abstract
Purpose::
The Goldmann diplopia field is the established standard for quantifying double vision, providing a percentage score for the area of diplopia. It is not known how well this measure compares to the patient’s perception of diplopia severity in everyday life. We used a previously developed patient symptom questionnaire addressing 7 positions of gaze (rating diplopia as always, sometimes or never), weighting primary and reading higher than peripheral gazes. We compared the questionnaire score to the score on the Goldmann perimeter.
Methods::
76 patients with strabismus and binocular diplopia were assessed using the diplopia questionnaire and the Goldmann perimeter. Scores were scaled 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 score and the questionnaire score, 2 observers reviewed details of the full eye exam and classified the reasons for the discrepancies. The primary reason for the discrepancy was determined by consensus.
Results::
Questionnaire scores ranged from 4 to 100 and Goldmann scores ranged from 0 to 100. Overall, there was fair agreement between the questionnaire and the Goldmann (ICC= 0.53, 95% CI 0.35 - 0.68). Nevertheless, 31 (41%) of 76 patients had >20-point discrepancy. 13 (42%) of 31 exhibited a higher diplopia score using the questionnaire than the Goldmann and 18 of 31 (58%) showed a higher diplopia score using the Goldmann than the questionnaire. The two most frequent reasons for a higher questionnaire score were test distance of the Goldmann (6 of 13 cases), and suppression in the Goldmann (3 of 13 cases). The two most frequent reasons for a higher Goldmann score were patient adaptation to diplopia (9 of 18 cases) and difficulty fusing the white target on the white background of the Goldmann (4 of 18 cases).
Conclusions::
The symptom questionnaire score appears to better represent diplopia than the score on the Goldmann perimeter. The questionnaire captures diplopia in the distance, suppression and fusion in everyday life and patient adaptation. The 7-position symptom questionnaire is a useful tool for quantifying diplopia in strabismus management and for clinical trials.
Keywords: strabismus • clinical (human) or epidemiologic studies: systems/equipment/techniques