Can you tell me why posterior vitreous detachment is more common in people who have undergone cataract operations?

Posterior vitreous detachment (PVD) does appear to be more common in individuals who have had cataract surgery, although there is not a proven genuine "cause and effect" for this fact. The relationship is multi-factorial:

• The vitreous changes that lead to vitreous liquefication, instability, and ultimately PVD are age-related, and so are the odds of significant cataracts and the need for surgery.
• The removal of the cataract can allow shifts in the vitreous gel and perhaps increase the odds of PVD.
• Biochemical changes in the vitreous gel occur following cataract surgery, and these appear to increase the likelihood of PVD, particularly if the posterior lens capsule is opened.
• Unusual complications of cataract surgery can disrupt the integrity of the vitreous gel and increase the odds of PVD.