Mac stuck on apple logo, can't boot to disk utility...

iMac 2010 running Yosemite.

Stuck on apple logo with loading wheel but does not progress from here. Have booted in single user mode and proceeded to do the /sbin/fsck -fy steps until the volume was reported as okay, this did little to help. I can boot using the option key and can see the hard-drive and recovery partition are there however cannot boot using command+R to access the disk utility as it simply stays on the apple logo.

Was wondering if anyone could advise what to do from here.

Thanks in advance.