Early retirement.

Not quite the same situation as you, I had left an organisation that had a Civil Service reserved rights pension scheme attached to it about 10 years before I had to take the decision to give up work due to my worsening condition. I contacted the previous employer explaining my condition and stating that had I still been working for them then I would have faced compulsory early retirement on medical grounds. I was pleasantly surprised when they came back to me saying that there was a facility to pay my pension early under those conditions subject to an independent medical assessment. That was a decade ago, it is by no means as much pension as it would have been had I been at retirement age but it certainly makes a difference.