Iatrogenic peripheral retinal breaks during vitrectomy more common than previously thought

This retrospective study included 629 patients (645 eyes) who underwent 20-gauge pars plana vitrectomy at a single center from 2005 to 2006.  This is the largest reported series of patients undergoing pars plana vitrectomy for indications excluding rhegmatogenous retinal detachment.

Intraoperative iatrogenic peripheral retinal breaks occurred in more than 15 percent of eyes, with wide variation by indication: tractional retinal detachment repair (22.2 percent), macular hole (18.1 percent), dislocated intraocular lens implant (16.7 percent), and epiretinal membrane (13.9 percent).  However, the frequency of post-vitrectomy rhegmatogenous retinal detachment was low (1.7 percent). Breaks were most common in the superior retina but also occurred at sites distant to sclerotomies. Eyes requiring surgical induction of a posterior vitreous detachment had 2.9 times greater odds of developing iatrogenic peripheral retinal breaks than eyes with preexisting posterior vitreous detachment (P<0.001), and phakic eyes had 2.4 times higher odds of break formation (P=0.001). 

The authors conclude that the appearance of breaks in both the superior retina and at sites distant to sclerotomies confirms that they arise not only from traction at entry sites and intraocular manipulation but also from the process of vitreous separation from the peripheral retina.