Small-gauge Instruments Research Articles

PMU1 A SYSTEMATIC LITERATURE REVIEW OF THE EFFICACY AND SAFETY OF MICROINCISION VITRECTOMY SURGERY TOOLS IN VITREORETINAL DISEASES

Microincision vitrectomy surgery (MIVS) and small-gauge instrumentation have improved vitrectomy procedures and increased their application in a range of vitreoretinal conditions. The objective of this systematic literature review was to identify publications reporting the efficacy and safety of MIVS tools in vitreoretinal diseases in clinical and real-world settings. Search strategies using key terms were conducted in Embase®, PubMed®, and Cochrane databases, supplemented with grey literature searches. Citations were reviewed by two independent researchers. Comparative clinical trials and observational studies were included. Outcomes of interest included visual acuity, surgical success, and complications. Overall, 1,323 publications were retrieved and systematically screened for eligibility. Twenty comparative publications were eligible for analysis. The majority (n=13) of included publications were observational studies. Comparative evidence in included publications was related to probe gauge and cannulas (n=12), surgical platform (n=6), and method (n=2). Post-operative IOP was reported in 14 studies, with four publications reporting significant improvement in IOP compared to baseline, regardless of probe gauge, and two publications reporting significant differences related to the surgical platform. Procedure time was reported in 13 publications, for various procedures, ranging from 6 to 57 minutes comparing 20-, 23-, 25-, and 27-gauge instruments. Post-operative BCVA ranged from -0.1 to 1.8 logMAR, with significant improvement from baseline reported in five publications, regardless of gauge. Most commonly reported post-operative complications included hypotony (n=9), ocular hypertension (n=8), vitreous haemorrhage (n=8), and retinal detachment (n=7). There are numerous studies evaluating the use of various MIVS tools in vitreoretinal surgery, however, there is also a high degree of heterogeneity in study design, populations, time of assessment, and surgical tools across studies. The differences in population, vitreoretinal pathology, and time of assessment results in difficulties comparing outcomes across trials. Consistency in the measuring and reporting of outcomes is required to reliably make comparisons across studies.

Outcomes of Surgically Managed Proliferative Diabetic Retinopathy

Purpose: The purpose of this article is to conduct a retrospective chart review of the results of vitrectomy for diabetic vitreous hemorrhage (VH) and diabetic traction retinal detachment (TRD) using small-gauge instruments. Methods: We retrospectively reviewed medical records of all diabetic vitrectomies performed at the University of Louisville from 2012 to 2016 that had at least 6 months of follow-up. Patients included in this study underwent pars plana vitrectomy (PPV) for proliferative diabetic retinopathy complications. We analyzed the preoperative and 6- and 12-month postoperative visual acuities (VAs) in patients who had vitrectomy for their diabetic retinopathy. We also determined the proportion of patients who had best-corrected visual acuity (BCVA) of 20/40 or better and 20/80 or worse. In the patients who had BCVA of 20/80 or worse, we identified the reasons for the decreased VA. We also report intraocular pressure, demographic characteristics, operative techniques, and complications. Results: We identified 93 eyes that underwent diabetic vitrectomy; 81 eyes of 63 patients had at least 6 months’ follow-up. Of those 81 eyes, 40 eyes had VH only; the average duration of vision loss before surgery was 4.7 months. Forty-one eyes had TRDs with average duration of vision loss before surgery of 7 months. The presenting BCVA was 1.14 logMAR (20/300) in the VH-only group and 1.49 logMAR (20/600) in the TRD group ( P < .09). Six months after surgery, the BCVA was 0.59 logMAR (20/80) in the VH-only group but still 1.37 logMAR (20/500) in the TRD group ( P < .001). By 12 months after surgery (63 eyes), the BCVA was 0.60 logMAR (20/80) vs 1.09 logMAR (20/250), respectively ( P < .02). Technical success was achieved in 79 of 81 eyes. At 12 months after surgery, 22 eyes (55%) in the VH-only group and 19 eyes (46%) in the TRD group gained 15 letters or more (doubling the VA) compared with their presenting VA. In the VH-only group 7 eyes (18%) were 23-gauge (G) PPV, 22 (58%) were 25G PPV, and 9 (24%) were 27G PPV, while in the TRD group 15 (38%) were 20G PPV, 11 (27%) were 23G PPV, and 14 (35%) were 25G PPV. There was no difference in outcome with different gauges. Conclusions: While vitrectomy for complications of diabetic retinopathy was technically successful with small-gauge surgery, visual results were disappointing. Further work is needed to clarify the best timing of surgery to improve visual outcomes.

Management of Complex Tractional Retinal Detachments In Proliferative Diabetic Retinopathy

Fibrovascular proliferations and tractional retinal detachment in patients with proliferative diabetic vitrectomy pose unique challenges in management. Surgical outcomes have improved with the availability of modern instrumentation and pharmacotherapy. The availability of anti-VEGF agents, small gauge instruments, bimanual techniques and intraoperative optical coherence tomography have reduced the overall risk of complications and improved the visual outcomes.

Dropped lens fragment, dislocated intraocular lens.

Management of posteriorly dislocated crystalline lens has traditionally been performed with a standard 20-gauge vitrectomy system. The latest surgical platforms integrate multiple devices into single systems and feature advanced fluidics, vitreous cutting technology, and intraocular pressure control along with continued improvements in small-gauge instrumentation and wide-angle viewing systems. This allows truly robust removal of core vitreous and outstanding control of the surgical field on par with its 20-gauge predecessor, resulting in an expanded spectrum of complex vitreoretinal maneuvers feasible with 23- or 25-gauge systems. Posteriorly dislocated crystalline lens/intraocular lens is one such indication which can be safely and effectively managed by a 23- or 25-gauge vitrectomy system alone or combined with the 20-gauge fragmatome/forceps with lesser complications and early recovery.

Innovative Technologies in Pars Plana Vitrectomy - Minimally Invasive Vitrectomy System

Minimally Invasive Vitrectomy System is a concept that was developed during the past years with the goal to make pars plana vitrectomy a safer and a less traumatizing procedure. The development of small gauge vitrectomy systems has led to the decrease of tissue damage and the shortening of the operating time. Although MIVS is increasingly popular, its use varies substantially according to the personal experience of each vitreo-retinal surgeon. The transition from the 20 gauge to the small gauge vitrectomy (23G, 25G) is directly related to the global approach to vitrectomy regarding incision making, intraoperative fluidics, cutting technology, illumination and accessory instruments. The development of new instruments capable to overcome the size and lumen handicaps became necessary. The use of small gauge instruments has various consequences on the vitrectomy itself: the modification of fluidics during surgery, the decrease of illumination, the need of fewer accessory and multi-function instruments. For the past 12 months, we used 25+ vitrectomy system sustained by the Constellation platform, in 296 cases that required vitreo-retinal surgery. The clinical conditions were the following ones: rhegmatogenous retinal detachments (120 cases - 40.54%), vitreous haemorrhages (100 cases - 33.78%), tractional retinal detachments (35 cases - 11.82%), epimacular membranes (15 cases - 5.06%), nucleus/lens luxated into the vitreous cavity (11 cases - 3.71%), intraocular foreign bodies (6 cases - 2.02%), macular holes (5 cases - 1.68%), endophthalmitis (4 cases - 1.35%). In this paper, the personal experience of using MIVS in variate cases that required vitreo-retinal surgery is illustrated.

Short-term outcomes of dry pars plana posterior capsulotomy and anterior vitrectomy in paediatric cataract surgery using 25-gauge instruments

AimTo evaluate the safety and efficacy of dry pars plana posterior capsulotomy and anterior vitrectomy in paediatric cataract surgery using 25-gauge instruments.MethodsA consecutive series of 57 paediatric patients (80 eyes)...

Effectiveness of canalicular laceration repair using monocanalicular intubation with Monoka tubes

This study aimed to evaluate the clinical efficacy of canalicular laceration repair using monocanalicular intubation with Monoka tubes. A total of 36 single lacerated canaliculi were repaired using monocanalicular intubation with Monoka tubes, without mucosal anastomosis of the canaliculi, and were retrospectively reviewed. Demographic information, injury locations, associated ocular injuries, complications and outcomes were analysed. Mean patient age was 34 years (range 1-64 years). Tubes were removed at a mean of 4.2 months (range 3-6 months). There were 26 lower canalicular lacerations (72%) and 10 upper canalicular lacerations (28%). Overall, 34 of 36 cases (92%) showed improvement in symptoms and exhibited positivity on the dye disappearance test at 4-12 months after the procedure (mean 7.8 months). In total, 21 patients (58%) achieved complete success, 13 patients (36%) achieved partial success and two patients (6%) suffered surgical failure. Complications were seen in five cases and included two early tube protrusions, two punctal slits and one punctal granuloma. Monocanalicular intubation with Monoka tubes leads to successful outcomes without significant complications and offers an alternative to bicanalicular intubation in the treatment of monocanalicular lacerations.

Combination 20 and 23-gauge transconjunctival vitrectomy: A new approach

The advent of smaller gauge instrumentation allows for minimally invasive vitreoretinal surgery (MIVS) as compared to conventional pars plana vitrectomy. Sutureless posterior segment surgery has the advantages of faster wound healing, minimal surgical trauma, decreased convalescence period besides reduced postoperative astigmatism; however, slower gel removal and limited peripheral vitreous dissection are disadvantages with smaller gauge systems. We herein describe a new technique combining 23-gauge and 20-gauge vitrectomy to improve the effectiveness and outcomes of vitreoretinal surgery.

This issue of Acta

The cover illustration on this edition of Acta shows optical coherence tomography images before and after sheathotomy, as demonstrated by Crafoord et al. later in these pages. This issue of Acta contains three editorials. In one of these, Sven Crafoord, in Örebro, discusses the use of small-gauge instruments in vitrectomy, with reference to three articles on the use of 25-gauge instrumentation in vitrectomy that appear later in the journal. Einar Stefánsson explains the pathophysiology of branch retinal vein occlusion and its treatment and puts sheathotomy, vitrectomy, laser, anti-VEGF drugs and intravitreal steroids into context, and Buys et al. celebrate World Glaucoma Day in a guest editorial. Wang and associates, writing from Copenhagen and Basel, present a comprehensive review of central serous chorioretinopathy. Crafoord et al.’s paper on sheathotomy − discussed in Stefánsson’s editorial − describes a retrospective study of the technique as a treatment for branch retinal vein occlusion. Tokyo-based Shinoda et al. found visual recovery to be quicker in vitrectomy patients operated with 25-gauge instrumentation than in those in whom 20-gauge instruments were used. They found no difference between the groups at 1 year after surgery. Magalhaes et al., writing from São Paulo, found that infusion and aspiration rates varied between three different 25-gauge vitrectomy systems. In a further paper, Shinoda et al. point out that 25-gauge vitrectomy instruments may become jammed in the cannula in eyes with non-clearing vitreous haemorrhage. Yeung et al., of Taiwan, found a negative association between the severity of vitreous haemorrhage and visual outcome in rhegmatogenous retinal detachments. A severe vitreous haemorrhage increases the risk of proliferative vitreoretinopathy in these patients. Swedish authors Bengtsson et al. suggest that standard automated perimetry and short-wavelength automated perimetry may be useful for monitoring visual function outside the fovea in patients with diabetic retinopathy. German researchers Neubauer et al. compare two different camera systems for screening and grading of diabetic retinopathy. Yeh et al., based in Taiwan, present three patients successfully treated with vitrectomy without inner limiting membrane peeling for macular retinoschisis and foveal detachment in highly myopic eyes. Jonas et al., writing from Germany, describe the successful injection of autologous bone marrow mononuclear cells into the vitreous cavity in a diabetes patient. UK authors Ugarte et al. present a case of hypertensive choroidopathy, furnished with comprehensive illustrations. Karalezly, writing from Ankara, report on using intracameral triamcinolone acetonide to control postoperative inflammation in cataract surgery. Stockholm-based Mody et al. studied cataract formation induced by ultraviolet radiation in guinea-pigs. They found that ascorbate supplementation did not reduce the risk of cataract formation in this model. In an inter-country collaboration between Canada and France, Tournier et al. describe their findings that visual impairment is associated with an increased risk of depression in elderly subjects, as well as an increased risk of death. UK authors Miranda and Henson, based in Manchester, found that patients respond better to multiple-stimulus perimetry with verbal feedback than they do to single-stimulus automated perimetry. Meanwhile, London-based Bergin et al. report on a new algorithm for the analysis of Heidelberg retina tomograph images. Kirwan and O’Keefe, in Dublin, describe corneal hysteresis following LASIK and LASEK. Hysteresis did not correlate with the amount of corneal tissue removed, the size of the optical zone nor the patient’s age. We launch a new feature in this issue of Acta. Stockholm’s Professor Stefan Seregard is interviewed by Gunilla Magnusson. We hope to carry interviews and news items on a regular basis in this section. We also include a list of forthcoming conferences and courses. Readers of Acta are invited to notify the editorial office of conferences and courses they would like to see listed in the journal. I hope that this issue of Acta serves as a source of both pleasure and knowledge to its readers.

Surgical Outcomes of 25-Gauge Transconjunctival Vitrectomy Combined With Cataract Surgery for Vitreoretinal Diseases

To report surgical outcomes of 25-gauge transconjunctival vitrectomy combined with cataract surgery for the management of a variety of vitreoretinal diseases. A retrospective, interventional case study was conducted. Chart review of a consecutive series of 150 eyes of 144 patients who underwent 25-gauge vitrectomy combined with phacoemulsification and intraocular lens implantation for epiretinal membrane (n = 62), refractory macular oedema associated with retinal vascular disorders (n = 29), idiopathic macular hole (n = 21), non-clearing vitreous haemorrhage (n = 18), rhegmatogenous retinal detachment (n = 11), tractional retinal detachment associated with proliferative diabetic retinopathy (n = 7), and subretinal haemorrhage (n = 2). Main outcome measures included preand postoperative visual acuity, operating time, intraocular pressure, intra- and postoperative complications. The mean follow-up period was 9.7 months (range, 6 to 26). The mean overall visual acuity improved from 20/100 preoperatively to 20/38 at final visit (P <0.001). Statistically significant improvement of visual acuity was also observed in each subgroup. Operative time was shortened in macular surgery. No intraoperative complications were noted attributable to small-gauge instruments and no cases required conversion to 20-gauge standard instrumentation. However, 12 eyes (8%) required suture placement to at least one sclerotomy site. Postoperative intraocular pressure remained stable in most cases except 18 eyes (13%) with transient hypotony during the first week after surgery. One case of retinal detachment but no case of endophthalmitis was observed throughout the follow-up period. 25-gauge vitrectomy combined with cataract surgery is a safe and effective system for the management of a variety of vitreoretinal diseases, especially cases requiring minimal intraocular manipulation. Further study is recommended to evaluate potential postoperative complications.

Estudio experimental sobre la utilidad del aceite de copolímero de silicona-fluorsilicona (SiFO) en la cirugía vitreorretiniana

To evaluate the usefulness of silicone-fluorsilicone copolymer oil (SiFO) as an intraoperative tool and a vitreous substitute in vitreoretinal surgery. Handling properties of SiFO were tested and compared with those of perfluorooctane (PFO). The transparency of both substances was measured by spectrophotometry and subjectively assessed. Their tendency to dispersion was observed during injection in balanced saline solution (BSS) and after mechanized and manual shaking. Ease of injection and aspiration through small-gauge instruments was evaluated. Ocular tolerance to SiFO and PFO was studied after intravitreal injection in rabbit eyes: intraocular pressure, anterior segment inflammatory response and dispersion were evaluated, and a histopathological study was performed. Injection and aspiration of SiFO were more difficult than those of PFO because of its higher viscosity. PFO dispersed progressively into small droplets as early as two days after intravitreal injection, whereas SiFO remained as a single bubble for 14 days. Histopathologically both substances induced an inflammatory response over the inferior retina, with microvacuolated macrophages and foreign body giant cells, which were larger in eyes wearing SiFO. SiFO may be useful as an intraoperative tool, although its main drawback is a more difficult injection and aspiration compared to PFO. It has been well tolerated as a short-term vitreous substitute, but further clinical studies are needed.

Pars plana lensectomy by ultrasonic fragmentation: II. A poort procedure for routine cataract extraction

Removal of the lens through a pars plana incision may be carried out with an aspiration-cutting device in young soft lenses, and with ultrasonic fragmentation, combined with an aspiration-cutting probe, in older, harder lenses. Extremely hard lenses cannot be efficiently removed through small incisions. These techniques are most useful when combined with a pars plana vitrectomy so that the same sized incision may be used for both procedures. In a few other selected situations, lensectomy through a pars plana incision is also advantageous. Adoption of this incision site for routine senile cataracts is unwarranted because: 1) small gauge instruments have little ability to remove very hard lenses; 2) vitreous must be incised in all cases, opening the door to unnecessary complications; and 3) loss of lens fragments into the posterior segment in 30–40% of eyes produces an unacceptably complex surgical procedure compared to limbal extraction.