VA LTR from Risk Managaer

Hello, I went to the VA complaining about the loss of vision in my right eye. I was given an exam, testing to take pictures of the inside of my eye. The optomotrist told that the test came back normal and that everything was fine. She increased my glasses prescription by +1 diopter and said goodbye. I had my wife make me an appointment at her eye doctor. They found what they thought was just a detached retina, but after several more visits at specialists they found out that it was occular melanoma causing my problems. My ocular oncologist helped me get the VA to pay for the surgury/radiation treatments. I got home form Memphis and got an express letter from the VA RO risk manager with some papers telling me that I needed to contact them, and a couple pages about my patient rights and 1151, tort claim, and that I could take legal action against her personally if she was contracted by the VA. My question is this: is not catching the eye cancer enough to file a claim? At TDIU how would that benefit me? If I file a claim would they open up all of my current service-connected disabilities in a C&P exam?  I'm trying to recover and hadn't even thought about seeking anything from her mistake. Thanks for any ideas on this.