Valved versus nonvalved cannula small-gauge pars plana vitrectomy for repair of retinal detachments with Grade C proliferative vitreoretinopathy

Abstract

PurposeValved cannulas are a recent addition to small-gauge pars plana vitrectomy (PPV) and provide stable intraocular fluidics. The goal of this study was to compare outcomes and postoperative complication rates of valved vs nonvalved cannula small-gauge PPV for repair of retinal detachments (RDs) complicated by Grade C proliferative vitreoretinopathy (PVR).MethodsA retrospective chart review of 364 consecutive eyes with either valved or nonvalved cannula PPV for RD repair was performed. The primary outcomes were single surgery and final anatomic success and change in best-corrected visual acuity for repair of RDs complicated by Grade C PVR.ResultsWe identified 36 eyes in the valved group and 31 eyes in the nonvalved group with Grade C PVR RD. The single surgery success was 83% vs 77% (P=0.555) and the final anatomic success was 94% vs 87% (P=0.404) in the valved vs nonvalved eyes, respectively. The mean final visual acuity gain was −0.36 logarithm of the minimum angle of resolution (logMAR; approximate Early Treatment Diabetes Retinopathy Study [ETDRS] score =17 letters) in valved eyes vs −0.33 logMAR (approximate ETDRS score =16 letters) in nonvalved eyes (P=0.81). Postoperative complication rates including postoperative day 1 hypotony, hypertony, and anterior chamber fibrin formation; postoperative retention of intraocular or subretinal perfluorocarbon liquid; and subsequent epiretinal membrane peel were not statistically different between groups.ConclusionValved cannula PPV yields equivalent visual acuity and anatomic outcomes without increased postoperative complication rates compared to traditional nonvalved cannula PPV for Grade C PVR-associated RD repair.

Proliferative Vitreoretinopathy: A Review

“…4,5 The incidence of PVR has largely remained unchanged in prospective studies despite the evolution of vitreoretinal techniques over the past 25 years, including valved trocars and smaller gauge instumentation. 6–9…”

<p>Hybrid 23/27 Gauge Vitrectomy – Combining the Charm of 27G with the Efficacy of 23G</p>

“…2,3 As smaller sclerotomy size leads to lower surgical trauma to the ocular surface, 15 efforts are underway to further reduce the size beyond 27G. 13,[16][17][18] Despite having theoretical advantages, 18 27G vitrectomy has not generally been accepted as the new MIVS standard. This may be related to technical challenges resulting from the small opening of the cutter, namely detaching a strongly adherent vitreous, particularly in younger individuals, and cutting back the vitreal base.…”

“…To address these issues, surgeons may need to switch to larger sclerotomy diameters intraoperatively (published values state that this occurs in 25% to 41% of very small incision surgeries). 9,20,21 Despite reports that the problem of insufficient illumination, as a result of ever smaller diameters of optical fibers used, has been resolved through technical advances, 2,17 others report an increased use of chandelier illumination in bimanual vitrectomy. 17,22 To avoid having to switch sclerotomy diameters intraoperatively and optimize outcomes, some authors considered mixing different sizes of small gauge vitrectomy depending on the specific surgical needs.…”

“…9,20,21 Despite reports that the problem of insufficient illumination, as a result of ever smaller diameters of optical fibers used, has been resolved through technical advances, 2,17 others report an increased use of chandelier illumination in bimanual vitrectomy. 17,22 To avoid having to switch sclerotomy diameters intraoperatively and optimize outcomes, some authors considered mixing different sizes of small gauge vitrectomy depending on the specific surgical needs. 5,6,23 The performance of new developments in vitrectomy, namely smaller gauge instrumentation, must be compared to existing technologies with regard to vitrectomy duration and safety outcomes.…”

Rescue Intravitreal Methotrexate Treatment Following Early Recognition of Proliferative Vitreoretinopathy

“…Despite advances in surgical techniques and equipment, the incidence of PVR remains between 5% and 10%. 2,3 Abnormal cellular proliferation results in the formation of membranes that can exert traction on the retina, ultimately leading to redetachment. Multiple therapies have been proposed for PVR, and currently, there is no proven medical treatment.…”