Ok, so the “no pain, no gain” doesn’t really make too much sense as the point of this tip and trick is for better visualization of the eyeball : INCREASE THE GAIN! Puts a whole new meaning to the term “Bright eyes.” When you have a patient with painful or painless vision loss, unilateral visual field deficit, trauma to the eye, or if you have a suspicion of a foreign body in the globe – increase the gain – yup, that’s right. Even though the eye is filled with fluid, and fluid is the lover of ultrasound allowing better visualization of structures deep to it on the screen, it can be difficult to visualize WITHIN that fluid filled structure. Lets see some examples:
When the gain is not adjusted, here is what you may see when fanning the eye of a patient with painless vision loss:
Now, if you increase the gain and have the patient move their eye in the direction that is in plane to the transducer, you’ll see that Vitreous hemorrhage swimming in the posterior vitreous chamber a lot better:
The same GAIN adjustment can help with retinal detachment evaluations: note the difference in the two below:
SonoSpot: Topics in Bedside Ultrasound 