Ex vivo Comparison of Intraocular Pressure Fluctuation during Pars Plana Vitrectomy Performed Using 25- and 27-Gauge Systems.

INTRODUCTION: The purpose of this study was to compare intraoperative intraocular pressure fluctuation using different aspiration systems and 25- and 27-gauge vitreous surgery probes. METHODS: Ex vivo, pars plana, 25- and 27-gauge vitreous surgery was performed on 4 porcine eyes, and IOP fluctuations were evaluated. We performed 3-port vitrectomy using the Constellation® Vision or the EVA® Phaco-Vitrectomy system. Each 20-s experiment was conducted 5 times for each set of conditions, each with the same substituted balanced salt solution. Real-time intraoperative intraocular pressure measurement was performed at the distal end of the infusion tube. Intraocular pressure was measured during core vitrectomy, core vitrectomy with fluid aspiration, peripheral vitreous shaving with scleral indentation, and fluid-gas exchange. The Mann-Whitney U test was used to evaluate statistical significance. RESULTS: Mean ± standard deviation intraoperative intraocular pressure fluctuation during 25- and 27-gauge core vitrectomy was 15.9 ± 1.6 and 11.9 ± 1.4 mm Hg, respectively (p < 0.05), using the Constellation system; 23.2 ± 1.4 and 14.1 ± 0.7 mm Hg, respectively (p < 0.001), using the EVA vacuum mode; and 15.0 ± 0.5 and 11.5 ± 1.4 mm Hg, respectively (p < 0.05), using the EVA flow mode. The smallest intraoperative intraocular pressure fluctuations during core vitrectomy with fluid aspiration, peripheral vitreous shaving with scleral indentation, and fluid-gas exchange were all achieved using the 27-gauge EVA flow mode; these values were 14.2 ± 0.4, 35.7 ± 0.9, and 6.4 ± 0.2 mm Hg, respectively. CONCLUSION: Regardless of the aspiration system, intraoperative intraocular pressure fluctuation was lower during 27-gauge than during 25-gauge vitrectomy. The 27-gauge EVA flow mode produced optimal intraoperative intraocular pressure stability.

Multicenter survey of sutureless 27-gauge vitrectomy for primary rhegmatogenous retinal detachment: a consecutive series of 410 cases.

PURPOSE: To evaluate the surgical outcomes of the 27-gauge (G) vitrectomy system for the treatment of primary rhegmatogenous retinal detachment (RRD). METHODS: This retrospective consecutive series multicenter study involved a total of 410 eyes of 406 patients who underwent 3-port transconjunctival 27G pars plana vitrectomy (PPV) for RRD between November 2014 and December 2016 and who were followed for a minimum of 3 months postoperative. The main outcome measure was primary reattachment, with the secondary outcome measures being final reattachment, improvement of visual acuity (VA), intraocular pressure (IOP), intraoperative and postoperative complications, and surgery time. RESULTS: Of the 410 treated eyes, primary reattachment was achieved in 392 (95.6%) and final reattachment was achieved in 410 (100%). In 226 eyes (55.1%) with macula-on RRD, the mean logarithm of the minimum angle of resolution (logMAR) VA improved from 0.16 ± 0.51 pre-surgery to 0.02 ± 0.14 post-surgery (P = 0.11). In 184 eyes (44.9%) with macula-off RRD, logMAR VA improved from 1.06 ± 0.77 pre-surgery to 0.26 ± 0.35 post-surgery (P < 0.001). Following surgery, the mean IOP was highest at 1 day (15.7 ± 7.0 mmHg) postoperative. In all eyes, surgery was concluded without the use of sutures or the need of conversion to a larger-gauge instrument. Although hypotony was observed in 14 (3.4%) of the 410 treated eyes at 1 day postoperative, it spontaneously resolved within 1 week without additional surgical intervention. No postoperative complications such as infectious endophthalmitis were observed throughout the follow-up period. CONCLUSION: Our findings show that 27G PPV is both safe and effective for the treatment of primary RRD.