Three-Step Incisions in 23-Gauge Vitrectomy Reduce Postoperative Hypotony: A Comparison With Oblique Incisions

Abstract

Purpose: : The standard sclerotomy for the 23-gauge sutureless vitrectomy is created by a straight incision at an oblique angle. In this technique, potential wound leakage and subsequent postoperative hypotony remain as common complications. To achieve a completely water-tight incision, we attempted a three-step incision in a similar way to that in cataract surgery. The aim of this study was to compare the incidence of postoperative hypotony and other complications between the two techniques.

Methods: : Patients with epiretinal membrane or macular hole, and no history of previous vitrectomy were included in the study. The conventional oblique incision procedure during 23-gauge vitrectomy was performed in 27 eyes of 27 consecutive patients (mean age, 66.2 ± 9.5 years) from January through November 2007, and the three-step incision procedure in 45 eyes of 43 consecutive patients (mean age, 67.7 ± 9.6 years) from November 2007 through October 2008. The surgical procedures were performed by a single surgeon. Intraocular pressure (IOP) was measured, and each sclerotomy site was evaluated with anterior segment optical coherence tomography (OCT) on the postoperative day.

Results: : No cases of hypotony (<6 mmHg) were recorded in the three-step group on the postoperative day, compared with 3 cases (11%) in the oblique group (P < 0.05). The three-step incision resulted in significantly higher mean IOP than the conventional incision did on the postoperative day (14.1 ± 6.7 mmHg vs. 10.9 ± 3.7 mmHg, P < 0.05). There was no hypotony in any of the eyes with fluid-gas exchange (three-step group: 0 of 16 eyes, oblique group: 0 of 8 eyes). In the eyes without fluid-gas exchange, the incidence of hypotony was 0% (0 of 29 eyes) in the three-step group, and 16% (3 of 19 eyes) in the oblique group (P = 0.056). OCT examination on the postoperative day revealed the well-sealed or non-detectable sclerotomies by three-step incisions and the partially gaped sclerotomies by oblique incisions both without vitreous incarceration. The three-step technique did not increase the incidence of other postoperative complications compared with the oblique technique.

Conclusions: : The three-step incision in 23-gauge vitrectomy effectively prevented the incidence of postoperative hypotony and demonstrated a favorable safety profile.

Keywords: vitreoretinal surgery • clinical (human) or epidemiologic studies: systems/equipment/techniques • intraocular pressure