Evaluation of microincision vitrectomy wounds made with microvitreoretinal blade or beveled trocar by swept source optical coherence tomography.

Purpose: To compare the wound closure and postoperative hypotony after sclerotomy with a microvitreoretinal (MVR) blade trocar with those with a beveled trocar for microincision vitrectomy.

Methods: The study design is a prospective randomized control study. Forty eyes of 40 patients with an epiretinal membrane that underwent 25-gauge transconjunctival sutureless vitrectomy were studied. One hundred and twenty sclerotomies were observed by swept source optical coherence tomography at 3 hours and at 1, 3, 7, and 14 days postoperatively. A closure of the sclerotomy site was defined as an absence of a scleral gap in the swept source optical coherence tomography images. The closure rate of the sclerotomies, intraocular pressures, and the incidence of complications were compared between the sclerotomies performed with an MVR blade and those with a beveled trocar.

Results: The rates of sclerotomy closure at 3 hours and at 1, 3, 7, and 14 days were 30.0%, 38.3%, 43.3%, 66.7%, and 95.0% with the MVR blade trocar and 21.7%, 26.7%, 36.7%, 53.3%, and 86.7% with the beveled trocar, respectively (P > 0.05 for all, Fisher exact test). The mean size of the sclerotomy was 143.9 ± 45.5 μm with the MVR blade and 158.7 ± 61.7 μm with the beveled trocar (P = 0.55, Mann-Whitney U test). The mean angle of the sclerotomies was significantly larger with the MVR blade trocar (48.9° vs. 45.8°; P = 0.049, Mann-Whitney U test). No significant difference in the speed of wound closure was found between the 2 groups (P = 0.174). Hypotony was not observed in both groups, and the intraocular pressure did not differ significantly between the two groups.

Conclusion: The absence of significant better rates of self-sealing and faster recovery of sclerotomies made with the MVR blade trocar and the bevel trocar indicates that these factors are not related to the type of trocar.