Risk of iatrogenic peripheral retinal breaks in 20-G pars plana vitrectomy

Purpose: To estimate the frequency and risk factors for entry site and other peripheral iatrogenic retinal breaks in eyes undergoing standard 20-G 3-port pars plana vitrectomy.

Design: Single-center, retrospective, interventional case series.

Participants: A total of 645 eyes undergoing pars plana vitrectomy at Moorfields Eye Hospital during the period June 1, 2005, to June 1, 2006, for indications excluding rhegmatogenous retinal detachment.

Methods: Case note review. Exclusion criteria were preexisting retinal breaks or rhegmatogenous retinal detachment, previously vitrectomized eyes, and iatrogenic breaks posterior to the equator.

Main outcome measures: Frequency, anatomic location, and risk factors associated with iatrogenic peripheral retinal breaks and rate of postoperative rhegmatogenous retinal detachment.

Results: Iatrogenic peripheral retinal breaks occurred in 98 of 645 eyes (15.2%) intraoperatively. Eleven of 645 cases (1.7%) experienced postoperative rhegmatogenous retinal detachment caused by undetected or new peripheral retinal breaks. Breaks were most common during surgery for tractional retinal detachment (22.2%), macular hole (18.1%), dislocated intraocular lens implants (16.7%), and epiretinal membrane (13.9%). Overall, breaks were more common in the superior retina (P<0.01), with 41.5% occurring in the 10 and 2 o'clock positions. Eyes requiring surgical induction of a posterior vitreous detachment had 2.9 times greater odds of developing iatrogenic peripheral retinal breaks (95% confidence interval, 1.8-4.7, P<0.001) than eyes with preexisting posterior vitreous detachment. Similarly, phakic eyes had 2.4 times higher odds (95% confidence interval, 1.42-3.96, P = 0.001) of break formation.

Conclusions: Iatrogenic peripheral retinal breaks caused by vitrectomy are more common than previously indicated. Approximately 4 in 10 breaks are related to traction at sclerotomy entry sites. Eyes undergoing surgery for tractional retinal detachment seemed to have the highest risk for break formation. Similarly, phakic eyes and eyes that require induction of a posterior vitreous detachment have more than double the risk for break formation.