Managing PVR in the Era of Small Gauge Surgery

Proliferative vitreoretinopathy (PVR) is the leading cause of failed rhegmatogenous retinal detachment (RRD) surgery. Based upon the presence of clinical features and due to associated underlying risk factors, it is classified into various grades based upon its severity and extent of involvement. Despite excellent skills, flawless techniques, and high-end technology applied in the management of RRD, PVR still occurs in 5–10% of cases. Due to the advancements in wide angle viewing systems, advance vitrectomy machines and fluidics, early identification, use of long-term heavy silicon oil tamponades, high-speed cutters, small-gauge vitrectomies, use of perfluorocarbon liquid (PFCL), and small-gauge forceps and scissors, the success rate in the management of PVR has increased leading to improved anatomical outcomes. However, functional outcomes do not correlate well with improved anatomical outcomes. Various complications occur after RRD repair that are responsible for re-retinal detachment and recurrence of PVR. This article highlights causes, risk factors, classification, grading, diagnosis, and approach to management of PVR and post-PVR surgery complications.

Intraoperative choroidal detachment during small-gauge vitrectomy: analysis of causes, anatomic, and visual outcomes

Introduction To investigate the incidence and causes of intraoperative choroidal detachment (CD) during small-gauge vitrectomy, as well as the anatomic and visual outcomes. Methods We retrospectively reviewed the medical records of 1026 consecutive patients who underwent small-gauge vitrectomy from June 2017 to December 2018 at Zhongshan Ophthalmic Centre, Guangzhou, China. Data on the presence, location, and extent of intraoperative CD and its relationship to the infusion cannula were collected. Patient demographic characteristics and postoperative anatomic and visual outcomes were also assessed. Results A total of six cases were found to have intraoperative CD, including two with serous CD, three with limited haemorrhagic CD, and one with CD caused by inadvertent perfusion of gas during air/fluid exchange. Retraction of the infusion cannula and acute ocular hypotony were found to be the main causes of intraoperative CD in five out of the six cases. The best-corrected visual acuity of all cases significantly improved after the surgery. Conclusion The incidence of intraoperative CD during small-gauge vitrectomy is low; the predominant causes are retraction of the infusion cannula and acute ocular hypotony. Immediate awareness and timely closure of the incision may contribute to a better surgical prognosis.

Full phase diagram of a UV completed $$ \mathcal{N} $$ = 1 Yang-Mills-Chern-Simons matter theory

We study the large N phase diagram of an asymptotically free UV completion of $$ \mathcal{N} $$ N = 1 SU(N) super-Yang-Mills-Chern-Simons theory coupled to a single massive fundamental scalar multiplet with a quartic superpotential coupling. We compute the effective superpotential at small gauge coupling λ ≡ N/k, and combine this with previous results in the literature to obtain the full phase diagram in this regime. We find that tuning the UV parameters allows us to reach various phases and fixed points of Chern-Simons theory that were recently discovered using large N techniques, as well as new phases that characterize the Yang-Mills theory. We also conjecture the form of the phase diagram for general values of λ and for finite N.

Surgical repair of primary non-complex rhegmatogenous retinal detachment in the modern era of small-gauge vitrectomy

ObjectiveTo report anatomic and visual outcomes of pars plana vitrectomy (PPV), as well as scleral buckling (SB) and PPV/SB as surgical treatments for the management of primary, non-complex rhegmatogenous retinal detachment (RRD).Methods and analysisData from 751 eyes that underwent PPV, SB or combined PPV/SB as a surgical treatment for primary non-complex RRD with at least 3 months of follow-up were analysed to determine rates of single surgery anatomic success (SSAS) and final anatomic success (FAS). Patients or the public were not involved in the design, conduct or reporting of this research.ResultsPPV accounted for 89.0% (n=668), PPV/SB for 6.8% (n=51) and SB for 4.2% (n=32) cases. Overall SSAS (91.2% PPV, 84.3% PPV/SB, 93.8% SB; p=0.267) and FAS (96.7% PPV, 94.1% PPV/SB and 100.0% SB; p=0.221) were reported for the three surgical groups. SSAS and FAS were similar for lens status, macular detachment status and the presence or absence of inferior retinal breaks for each of the PPV, PPV/SB and SB groups.ConclusionsIn this large, single institution, retrospective case series, we report surgical outcomes for patients with primary non-complex RRD managed with PPV, SB or PPV/SB in the modern era of small-gauge vitrectomy. We demonstrate that primary PPV without adjunct SB provides excellent anatomic and visual outcomes irrespective of lens status, macular involvement or pathology location.

Lens and Peripheral Retinal Relationships During Vitrectomy: Comparison of 23-, 25-, and 27-Gauge Vitrectomy and Curved Endolaser Probes

Purpose: This work aims to compare spatial relationships between the crystalline lens and vitrectomy instruments of different gauges. Methods: Eight phakic eyes recovered from deceased donors were used after fixation. Valved trocars (27-gauge, 25-gauge, and 23-gauge) were sequentially placed in the superotemporal quadrant 4 mm posterior to the limbus in each eye. Intraocular relationships of vitrectomy and curved endolaser probes were measured for each gauge. Results: There were no significant differences in maneuverability between instruments of different gauges. The mean distance from instrument to lens at the geometric center of the globe was 5.5 mm. Vitrectomy probes of all gauges could access the peripheral retina on both sides of the sclerotomy in the 3 to 4 o’clock position adjacent to the sclerotomy without touching the lens. The instruments could be advanced without lens touch to contact the retina within at least 2 mm of the ora serrata 180° away from the insertion site. Conclusions: Vitrectomy and curved endolaser probes achieved similar maneuverability relative to the lens regardless of gauge. This study confirms that small-gauge vitrectomy instruments have a considerable range of safe access to the peripheral retina in phakic eyes from a single sclerotomy.