Scanner Epson Perfect 4990 Photo

I was using this scanner connected via firewire to an iMac running MacOS X 10.7.

I updated to MacOS X 10.11 and now scanner works only via usb and not via firewire.

But I prefer use it with firewire; how can I do it?

I tried to download driver from Eposn site, I asked via mail to Epson support about it, but they wrote me that there are not driver for El Capitan and I have to use Apple software and so I'm here asking what I have to do.

Thank you.