What is a safe waiting period to have cataract surgery after a vitrectomy for a detached retina?

I don't think a safe waiting period has been determined. If you have a mature or hypermature (when most of the lens has become cloudy) cataract then early surgery should be considered, perhaps days to weeks. If you have a significant cataract before the retinal surgery then having the cataract surgery and retinal surgery at the same time can also be done. Furthermore, if your vision is compromised to the point of being unable to do the things you need to do then early surgery can be considered. If the cataract is not very advanced and you can function well, then waiting a period of three months would be considered standard. There is nothing magical about this number but it is generally accepted that the recovery time of a major eye surgery is about 90 days so it makes sense to wait three months before considering another surgery on the same eye. The advantages of this are that you know your retina has remained attached for 3 full months and the inflammation (swelling) from the prior surgery is likely to be resolved.