The answer is that it all depends on exactly what you have. If you have significant scar tissue, it is often very difficult to remove and improve the vision especially since your vision is down so badly at present. You can hopefully get a new IOL and that may also help some. I'm really sorry but I cannot make any specific recommendations since I don't know what you really have other than a retinal detachment repair and no lens, and low pressure. The prognosis sounds difficult at best.
MJK MD
How low is your IOP? (anything less the 6 mmHG is definitely hypotony and can cause problems) Sometimes the IOP can rebound and land in the normal range of 10-21 mmHG, but it takes time.
Depending on the situation, sometimes the risks of surgery are too high to undertake. Your surgeon may feel that it is not safe to operate on your eye to remove the ERM and implant an IOL at this time as these surgeries can do more harm to your eye: nerve damage, complete retinal detachment w/more PVR, infection etc.
I would recommend a second opinion. If you live in the U.S. visit www.aao.org to find a vitreo-retinal specialist near you.