cataract surgey gone wrong?

Hi, I just got back from visiting my mom in Washington state ; she recently had a cataract surgery done and now she is blind from her right eye and the doc. says she is at risk on losing her left eye aswell.  The Doc. suspects it's Giant Cell Arteritis she is on steroids for now till docs. find out if this is what she has. They arleady performed a left and a right eye temporal artery biopsy and both came back negative. Talking to my mom, she said during the cataract surgey on her right eye she had a lot of pain and continued to have pain till she lost her vision. I belive it was a cataract surgey gone wrong.
Please help with any info you might have.
Thanks.