Iatrogenic retinal breaks in 20-G versus 23-G pars plana vitrectomy

The purpose of this study was to compare the incidence of iatrogenic anterior retinal breaks in 20-G vitrectomy (PPV) with transconjunctival 23-G PPV. Retrospective, observational review study involving consecutive patients undergoing PPV in a single center in the UK during a 2-year period. Sclerotomy-related entry-site breaks (ESB) were found in 50/628 (7.9 %) 20-G PPV cases and 5/296 (1.7 %) 23-G PPV eyes (p < 0.0001*). Anterior non-sclerotomy iatrogenic breaks (ANSB) were present in 55/628 (8.7 %) 20-G PPV cases and 18/296 (6.1 %) 23-G PPV eyes (p = 0.19). The incidence of total anterior iatrogenic breaks (ANSB + ESB) was 105/628 (16.7 %) for 20-G PPV and 23/296 (7.8 %) for 23-G PPV (p = 0.002*). Univariate analysis showed that posterior vitreous detachment induction was the only risk factor significantly associated with the development of anterior retinal breaks for both 20-G and 23-G PPV. Multivariate logistic model of risk factors for development of iatrogenic retinal breaks demonstrated that 23-G PPV was the most important factor reducing the risk of anterior breaks (p < 0.0001*). We report the largest series of patients undergoing 20-G and 23-G vitrectomy, where 23-G vitrectomy was associated with a significantly lower incidence of anterior iatrogenic retinal breaks.