We thank Drs Wa and Sebag for their interest in our article, “Safety of Vitrectomy for Floaters.” They question our strategy to perform posterior vitreous detachment (PVD) induction in eyes with an attached posterior vitreous. We documented more retinal breaks in the cases in which PVD was induced during surgery. Because retinal breaks are a prerequisite for the development of a retinal detachment, they argue that it would be safer to refrain from PVD induction in these cases.
There are some concerns with this line of thought. Although previous studies have corroborated a correlation between PVD induction and retinal breaks, a causal relation cannot be deduced. In all studies, the risk of retinal breaks is compared between a group of eyes with an attached vitreous that underwent PVD induction and a group of eyes with preexisting PVD that did not need PVD induction. An eye that has gone through a spontaneous PVD is quite different from an eye with an attached posterior vitreous. An eye with an attached vitreous will have less vitreous synchesis and syneresis and tighter vitreoretinal attachments. Vitrectomy in these so-called younger eyes is expected to result in a higher risk of break formation, independent of PVD induction. Thus, the evidence is circumstantial. Evidence for a direct relationship between PVD induction and break formation is—to our knowledge—not available.
The reason why we choose to perform a PVD in these cases is our concern with long-term complications. Leaving the posterior vitreous membrane attached implies that PVD is still going to occur after primary vitrectomy. This will lead to recurrence of floaters at a later date when spontaneous PVD occurs, in some cases necessitating repeat surgery. More disquieting is the fact that this secondary PVD has a high risk of being of the premature, anomalous kind, implying an increased risk of resulting in peripheral traction and retinal detachment. Although no literature is available, it is our personal experience that recurrence of floaters is not rare after removal of only the core of the vitreous. Furthermore, if late retinal detachment occurs after floater surgery, it tends to occur in eyes with an intact posterior vitreous membrane.
In our series of 116 vitrectomies, 3 were complicated by postoperative retinal detachment. Drs Wa and Sebag state that all 3 occurred in eyes that had a PVD induction. This is not the case. Two retinal detachments occurred in eyes that had pre-existing PVD and no intraoperative PVD induction. One retinal detachment did occur after active PVD induction.
The question of whether to induce PVD during floater surgery is quite complex and, to date, remains unanswered. We wish to stress that, whichever strategy is chosen, meticulous intraoperative search and treatment of breaks is a crucial step in the vitrectomy and is the most decisive factor in the prevention of RRD. Despite the controversy that exists about surgery on vitreous floaters, patients more and more demand recognition of their symptoms. Happily enough, more and more physicians take the reports of their patients seriously. Very recently, important evidence emerged on the high impact of floaters on health-related quality of life. It can be expected from this that the number of floater treatments will increase in the near future. This certainly would validate further study in this still unsolved matter.