Most pearls you find are small yet still collected and saved, and this clinical pearl is no different. On a recent SVOSH trip, I went through several bottles of tropicamide to dilate patients’ eyes. In an effort to avoid inducing nausea for the patient (among other side effects), we made sure to check for open angles before implementing tropicamide. I recommend taking ten seconds to perform this simple task before dilating a patient’s eyes.
To check for open angles in the right eye, hold your transilluminator (or any small light source) in your left hand. Shine the light into the right eye diagonally, in which the light comes from the patient’s right field of view and lands on nasal retina. However, you aren’t concerned about the retina in this brief test. You are looking for a halo of light to appear nasally around the limbus (see photo). If you observe this halo, the angles are open; if no halo appears, the angles are closed.
For the left eye, hold the transilluminator in your right hand, and everything mentioned above is opposite. Of course you could perform this task from different approaching angles towards the patient’s eye, looking for a halo of light present at the opposite side of the pupil as the transilluminator.
Feel free to ask questions or make suggestions below!