Best investigation for optic nerve damage amongst the following is:

D i.e. Perimetry Investigations for Optic Nerve Disease Perimetry : Visual field defects are best detected by Goldmann kinetic perimetry (full-field) & Humphery automated threshold perimetry MRI: Best investigation for imaging of optic nerves Visually evoked potential Fluorescein angiography: Occasionally helpful in differentiating papilloedema(showsdisc leakage) from optic disc drusen (no leakage). Ophthalmoscopic appearance of the disc may vary considerably from normal to elevated to arophied, so they may not help in diagnosis, though may be useful in differential diagnosis. USG is not used for evaluation of optic nerve but for retinal function and structure.