Ophthalmoscope useful to see palliedema?

Yes. It allows you to see the optic nerve which would need to be swollen to have the diagnosis of papilledema.
Standard method. Papilledema is a swelling of the tissues at the optic nerve. This can be seen with an ophthalmoscope as long as there is a clear pathway to view the back of the eye. This is the standard way to detect this sign which commonly is related to increased cerebral sinus pressure.