When the patient complains of diplopia (especially new diplopia), we must ask more questions to help the doctor determine the cause of the double vision, or whether it truly IS double, or just blurry or “ghosting” of images.
1. Monocular or binocular? “Have you tried covering one eye? Does it go away when you do cover one or either eye? Is it always the same eye that has the problem?” Binocular diplopia is related to the eye muscle’s alignment and requires the doctor to see the patient prior to dilation for the best assessment. Monocular diplopia is usually from something in that eye’s visual pathway (cornea, lens or retina) and the doctor wants the patient dilated to assess the cause. (Add a sticky note to the doctor, as to why you dilated a diplopia patient, as an extra “heads up”).
2. Is it two distinct images or just “ghost overlap?”
3. Are the images one on top of one another, or side by side or “oblique?”
4. Constant or intermittent? If intermittent, how frequent (what percentage of the time)?
5. Only with certain activities or gazes? Is there something you can do to make it go away (blinking?, moving head? tiliting glasses? tiliting or turning your head?)
6. Distance or near or both?
7. With glasses on or without or both?
8. Accurately record the patient’s glasses and look for prism. Most patients know if they have prism because it adds considereably to the cost of the glasses.
Finally, we must do a careful motility test: cover-uncover to determine tropia vs. phoria and cross-cover to determine eso, exo or hyperdeviations. Remember to check the nine cardinal positions of gaze (including primary), eye ductions and versions (D and V) and convergence. IF you’re not sure how to record what you find, just write what you saw (ie. “OD looks ‘up and out’”).
Ductions: Monocular range of moment - recorded in relationhip to center (nose).
Adduction is movement toward the nose, and Abduction is movement away from the nose
Versions: parallel movement of BOTH eyes in any direction
Vergence: Movement of BOTH eyes in opposite directions.
