Avalanche Photodiode Current Gain
Sure it does. This photodiode works by having a detected photon kick loose an electron, which then undergoes an avalanche amplification with an amplification factor M. So each dark count produces (on average) M electrons. Multiply by the dark count rate and you have the dark current in electrons. Noise in these devices is a complex subject, and you need to do some research outside the data sheet to understand it.