Fused glass edge finishing could be required if the glass piece has not rounded properly, or is uneven and may also be spiked.
It may be that the fused glass has been under fired if the edges are not as round as you would like.
If the item has been under fired place it back in the glass fusing kiln and re-heat to a slightly higher temperature or leave on soaking temperature for longer.
If the fused glass edges have spikes then the piece has been over fired.
Grind spikes away, then re-fire glass at a lower temperature.
Temperatures of around 1350-1400 F (730-760 C) should be enough to rectify a fused item.