Risk of retinal breaks during vitrectomy: Impact of macular hole size and epiretinal membrane thickness

Dear Editor, Macular holes (MH) and epiretinal membranes (ERM) are macular disorders commonly requiring vitrectomy, with iatrogenic retinal breaks (RBs) a notable surgical complication.[1] Little is known regarding the baseline anatomical and functional parameters in MH and ERM that influence RB risk. We retrospectively reviewed 305 eyes that underwent surgery for MH (n = 154) or ERM (n = 151) at two tertiary Australian centers (Nov 2019 to Jan 2024), including six vitreoretinal surgeons; all secondary MH/ERM cases were excluded. Ethics approval was obtained (reference number: 19813), and the study adhered to the tenets of the Declaration of Helsinki. Pre-operative OCT (ZEISS CIRRUS®5000) was done to document the macular morphology. Three-port conventional pars plana vitrectomy (PPV) was performed with 25/27-G vitrectomy system (Constellation Vision System, Alcon), and RBs were diagnosed by 360-degree intraoperative search using the Resight system coupled with the Lumera-700 microscope. Using logistic regression and multivariable ANOVA, gauge size, induced posterior vitreous detachment (IPVD), surgeon identity, and morphological features (MH height/diameter, central foveal thickness) were assessed as potential risk factors. Patient clinical and surgical findings are displayed in Table 1. RBs occurred in 10.4% of MH and 12.6% of ERM surgeries, all detected intraoperatively. In MH surgery, IPVD (P = 0.037) and 25-G vitrectomy were significantly associated with increased RB risk (15% for 25G vs. 1.8% for 27G, P = 0.008). In contrast, gauge size and PVD status had no effect on ERM cases. No associations were found between MH width, base diameter, or height and RB occurrence. Central foveal thickness was associated with increased RB risk in ERM surgery (P = 0.010), likely reflecting surgical difficulty due to ERM adherence. Surgeon-specific RB rates ranged from 10–13.9%, but surgeon identity did not predict RB risk in either group (MH P = 0.67; ERM P = 0.72).Table 1: Surgical outcomes for macular hole and epiretinal membrane patientsThe lower RB rate observed with 27-G vitrectomy for MH cases likely reflects advantages, including smaller port size and reduced vitreoretinal traction.[2] This is consistent with prior evidence showing improved fluidics and lower intraocular pressure fluctuations in 27-G systems, though vacuum settings were standardized in our series (500–650 mmHg core vitrectomy and 20–300 mmHg peripheral vitrectomy).[3] The absence of a gauge effect in ERM surgeries may be explained by a reduced need for IPVD and associated tractional forces.[4] Notably, increasing ERM thickness correlated with higher RB risk, likely due to more aggressive surgical manipulation, greater use of intraocular instruments, and stronger ERM adherence causing peripheral traction during peeling.[5] This finding highlights an important morphological predictor to guide intraoperative vigilance and surgical planning. No association was found between MH morphology and RB risk, likely due to small sample size. Our results reinforce known RB risk factors, including IPVD and larger gauge size for MH surgery, while identifying ERM thickness as a novel risk factor in ERM surgery. These insights underline the importance of individualized surgical strategies tailored to patient anatomy. The lack of surgeon-specific influence on RB rates suggests that risks are consistent across operators, supporting broader clinical applicability. Further, larger-scale studies are needed to better characterize the morphological association between MH and ERM and surgical complications during PPV. Financial support and sponsorship: Nil. Conflicts of interest: There are no conflicts of interest.