Abstract
Purpose: :
. Despite its clinical advantages 25-g vitrectomy system poses significant challenges in vitreous removal; the main drawback is that the 25-g vitrectomy time is significantly longer than 20-g one, due to the low efficiency of current small-gauge cutters. The aim of this study was to compare the efficiency and safety of new generation ultrahigh speed (UHS) 25-g Alcon Constellation ® with Alcon Accurus® 25- and 20-g vitrectomy system.
Methods: :
New UHS 25-g Alcon Constellation ® has a 5000 cpm cut rate and a duty cycle (dc) control with maximum dc in the core mode and minimum dc in the peripheral shave mode. Dc is the percent of time during which the vitrectomy port remains open thus allowing aspiration. 30 consecutive eyes (m. age 67 ys) affected by ERMs, underwent 3 port pars plana vitrectomy (ppv) with UHS 5000 cpm 25-g Alcon Constellation ® (n.10), with 1500 cpm Alcon Accurus® 25-g (n.10), and 2500 cpm Accurus® 20-g (n.10).Surgical technique was complete Triesence ® assisted ppv, posterior hyaloid, ERMs and ILM removal, peripheral vitrectomy with with scleral indentation.Mean outcome measure was total vitrectomy time.
Results: :
At baseline all patients were pseudophakic, preoperative mean Visual Acuity was 0.48 logMAR in the UHS 25-g group , 0.47 logMAR in the standard Accurus® 25-g group , and 0.48 logMAR in the 20-g one, not different.Mean total vitrectomy time was 473 + 279 seconds (sec) with UHS 25-g, 632 + 208 sec with Accurus® 25-g , and 500 + 301 in 20-g.No intraoperative complications occurred dealing with the 3 groups, no complications related to the UHS was highlighted.
Conclusions: :
This study shows that the total vitrectomy time is shorter dealing with UHS sytem than with standard 25-g system, while is similar to 20-g time. This result is due to the optimization of the dc also dealing with UHS cut rate. This option improve vitreous flow efficiency of small diameters 25-g cutters that now can match performance of larger diameters 20-g cutters. Moreover the new UHS vitrectomy system is as safe as the standard ones. We know that 25-g technique is useful because reduces patients discomfort: therefore the increased efficiency of the new vitrector encourage a wide use of small-gauge mini invasive vitrectomy.
Keywords: vitreoretinal surgery • vitreous • macula/fovea