CONCLUSION: This study on eye motility demonstrates a new application of electro-oculography which proved to have a high potential for establishing and diagnosing the cause of diplopia in orbital floor fractures. Electro-oculography is objective and easy to perform even when the restricted eye is covered. The 'uninjured' eye can be used as the reference. Any motility difference between the left and the right eye was easily detected. OBJECTIVE: It is essential in orbital floor fractures to distinguish entrapment from other causes of diplopia. We investigated whether vertical eye motility and restricted elevation can be detected and characterized by means of electro-oculography. MATERIALS AND METHODS: Electronystagmography equipment used for vestibular testing in daily ENT practice was used in a different context. Unilateral mechanical restriction was generated in the test subjects through fixation of one eye bulb. The velocity and range of eye motility of both eyes were measured and compared in 12 healthy test subjects and 7 patients with long-term vertical diplopia after orbital floor fractures. RESULTS: Simulated entrapment was easily detected as a distinct difference between right and left eye motility recordings (p<0.001). Recordings of patients with diplopia differed significantly from those of healthy test subjects with respect to velocity (p<0.05) and range of motility (p<0.05).
CONCLUSION: This study on eye motility demonstrates a new application of electro-oculography which proved to have a high potential for establishing and diagnosing the cause of diplopia in orbital floor fractures. Electro-oculography is objective and easy to perform even when the restricted eye is covered. The 'uninjured' eye can be used as the reference. Any motility difference between the left and the right eye was easily detected. OBJECTIVE: It is essential in orbital floor fractures to distinguish entrapment from other causes of diplopia. We investigated whether vertical eye motility and restricted elevation can be detected and characterized by means of electro-oculography. MATERIALS AND METHODS: Electronystagmography equipment used for vestibular testing in daily ENT practice was used in a different context. Unilateral mechanical restriction was generated in the test subjects through fixation of one eye bulb. The velocity and range of eye motility of both eyes were measured and compared in 12 healthy test subjects and 7 patients with long-term vertical diplopia after orbital floor fractures. RESULTS: Simulated entrapment was easily detected as a distinct difference between right and left eye motility recordings (p<0.001). Recordings of patients with diplopia differed significantly from those of healthy test subjects with respect to velocity (p<0.05) and range of motility (p<0.05).