Well, blu rays are much harder to damage as apposed to CDs and DVDs. You can wash the disc with tap water if there is any dirt, dust or grime on the disc and wipe it center outwards with a soft cotton cloth.
If your disc is clean, then it's possible that your install data or HDD might be corrupt. Delete the old install data (not save data!) and re-install the game again. All DLCs will be wiped out too, so redownload them. If other games are giving you problem too, then it's most likely your HDD is going bad.
Another common cause that people tend to overlook is your lens. They WILL get dirty overtime, and this leads to lower sound quality and worst of all, disc read errors. I tend to dismantle my PS3 to get direct access to my lens and clean it with a q-tip and alcohol every few years, but I won't recommend this if you have no experience!
Your best way of preserving the lens is to always, without fail, make sure that your discs are clean. If they have been in storage for months, then they definitely need to be run under tap water.
Hope that helps!