In high young myopes, is there a chance of retinal detachment long after pvd is over?do we have to live with floaters/flashes with the fear of rd

Unfortunately yes: If you make it through your PVD without an rd, your risk becomes less. The flashes stop when PVD is completed. You may still have lattice retinal degeneration and corresponding risk of rd. Trauma and other causes initiate rd more often in high myopes. You can have preventative laser done to protect you from an rd stealing your vision.

No simple answer: High myopes always have a higher risk of retinal detachment (rd) than non-myopes. The risk is greatest while there are acute PVD symptoms (flashes, new floaters). Once the acute symptoms subside, the floaters are a nuisance that gets worse slowly, and the retinal detachment risk decreases sharply, but does not go away completely. Chronic floaters correlate poorly with rd risk.