Effects on ocular discomfort and tear film dynamics of suturing 23-gauge pars plana vitrectomies.

PURPOSE: To evaluate the effects of suturing 23-gauge pars plana vitrectomies on ocular discomfort and tear film dynamics. METHODS: This retrospective chart review involved data from 50 procedures in 50 patients who underwent 23-gauge pars plana vitrectomy from January to November 2016. We divided the eyes into two groups according to the presence or absence of sutures; 35 eyes underwent sutureless vitrectomies (Group 1), and 15 eyes underwent vitrectomy with at least one sclerotomy suture site (Group 2). In each group, we assessed objective variables including tear film break-up time, Schirmer test I, corneal surface grading with Oxford system, and a quantitative method evaluating subjective dry eye symptoms using ocular surface disease index questionnaires preoperatively 1 week, and 1 and 3 months after surgery. RESULTS: The tear film break-up time showed a significant difference at the 3-months follow-up (p=0.026). The Schirmer test I and corneal surface staining score showed no statistically significant differences between two groups at any time after the operations. The ocular surface disease index score was significantly lower in Group 1 than in Group 2 at 1 week (p=0.032), 1 month (p=0.026), and 3 months (p=0.041) after the operation. CONCLUSION: Sclerotomy suturing caused ocular discomfort and had a negative effect on tear film dynamics during the late postoperative period. Sclerotomies without suturing seem to reduce the ocular surface changes.

Trocar-Assisted, Sutureless, Scleral-Fixated Intraocular Lens Implantation Combined With Penetrating Keratoplasty.

PURPOSE: To evaluate the results of trocar-assisted, sutureless, scleral-fixated (SSF) intraocular lens (IOL) implantation combined with penetrating keratoplasty (PKP). METHODS: This study comprised 4 eyes (4 patients) undergoing trocar-assisted SSF-IOL implantation during PKP. The combined technique was performed in 3 eyes of 3 patients with bullous keratopathy and in 1 eye with central corneal opacity. Two eyes had anterior chamber IOL implants, and 2 were aphakic. All eyes had inadequate capsular support. Evaluated parameters were biomicroscopy, corrected distance visual acuity, intraocular pressure, IOL position, and corneal graft status. Intraoperative and postoperative complications and additional surgeries were recorded. RESULTS: The mean follow-up period was 28.3 ± 3.5 months. Trocar-assisted SSF-IOL implantation with PKP was successfully performed in all eyes. Visual acuity improved in all patients. During the follow-up period, a well-stabilized IOL without any IOL-related complication was obtained in all eyes. In one eye with corneal scarring and aphakic glaucoma caused by trauma, drug-resistant glaucoma developed 6 months after surgery requiring Express glaucoma shunt surgery. In one eye with a history of central retinal vein occlusion, repeat keratoplasty was performed after 10 months because of graft rejection. CONCLUSIONS: Trocar-assisted SSF-IOL implantation combined with PKP is an alternative method for visual rehabilitation in the eyes with bullous keratopathy and corneal scarring without sufficient capsular support.

NEXT-GENERATION DUAL-BORE CANNULA FOR INJECTION OF VITAL DYES AND HEAVY LIQUIDS DURING PARS PLANA VITRECTOMY.

PURPOSE: The objective of this study was to introduce and validate a next-generation dual bore cannula for microincisional vitrectomy surgery. METHODS: The SideFlo cannula with a closed tip and four vent ports on the sides was designed and manufactured. The cannula is designed to inject vital dyes for macular staining and perfluorocarbon liquids. Injection and venting properties were assessed subjectively in vivo, and venting was quantified in a plastic eye model system; 23-, 25-, and 27-gauge SideFlo cannulas were assessed and compared with existing axial dual bore cannula designs. RESULTS: The SideFlo cannula created a broad fan-like egress of fluid that was perpendicular to the axial direction of the cannula and eliminated the possibility for retinal fluid jet damage. Enhanced outflow venting was clinically relevant in terms of smoother injection experience and less intraocular pressure rise when compared with previous dual bore designs. Testing in a model eye system confirmed marked improvement in passive outflow compared with the first-generation dual bore cannula single vent port design for all gauges. CONCLUSION: The SideFlo cannula represents a novel next-generation dual bore cannula design with significantly improved performance over first-generation dual bore cannulas. Axial jet damage from fluid injection is eliminated, and pressure equilibration by passive venting from the eye is significantly enhanced.

Long-term hypotony because of accidental break of a 23 g microcannula after transconjunctival sutureless vitrectomy.

PURPOSE: To report a case of long-lasting hypotony because of accidental break, with scleral tunnel entrapment, of a 23-gauge microcannula during transconjunctival sutureless vitrectomy. METHODS: Interventional case report. An 80-year-old Spanish woman who underwent 23-gauge transconjunctival sutureless vitrectomy presented at the postoperative ocular examination with irreversible, refractory low intraocular pressure of unknown cause. Two weeks after surgery, a piece of the microcannula was found at the inferotemporal sclerotomy site during a scheduled medical appointment. Surgical intervention was indicated to explore and remove the foreign body. RESULTS: The day after foreign body extraction, the patient's pressure rose to normal levels. However, her visual acuity did not improve until 3 weeks later. CONCLUSION: Transient postoperative hypotony is unsurprising after 23-gauge vitrectomy because of leakage of small-diameter open sclerotomies. However, when long-term low intraocular pressure fails to return to normal levels because of an unidentified condition, breaking of the microcannula piece with scleral tunnel entrapment may be contemplated.

Machines and cutters: VersaVIT - potential and perspectives of office-based vitrectomy.

The concept of office-based vitrectomy has been a topic for several years; however, the large size of the vitrectomy machines has limited the options for many years. Today, though, smaller machines can offer adequate performance regarding vitrectomy. As a result, we can now make more arguments for this type of surgery to be performed in the office environment, despite the limitations these machines may still have.

[Evaluation of microbial growth on single-use vitrectomy probes reprocessed in healthcare practice]. / Avaliação do crescimento microbiano em sondas de uso único para vitrectomia reprocessadas na prática assistencial.

The aim of this study was to evaluate the microbial growth on single-use vitrectomy probes reprocessed in healthcare practice. We investigated nine vitrectomy probes that had been reused and reprocessed using different methods. The samples were sectioned, individually, in portions of 3.5 cm, totaling 979 sampling units (extensions, connectors and vitrectomy cutters), which were inoculated in culture medium and incubated at 37º C for 14 days. The results showed microbial growth on 57 (5.8%) sample units, 25 of which had been sterilized using ethylene oxide, 16 by hydrogen peroxide plasma, and 16 by low-temperature steam and formaldehyde. Seventeen microbial species were identified. The most prevalent were: Micrococcus spp., coagulase-negative Staphylococcus, Pseudomonas spp., and Bacillus subtilis. The reuse of single-use vitrectomy probes was shown to be unsafe, therefore this practice is not recommended.

Avaliação do crescimento microbiano em sondas de uso único para vitrectomia reprocessadas na prática assistencial / Evaluation of microbial growth on single-use vitrectomy probes reprocessed in healthcare practice / Evaluación de crecimiento microbiano en sondas de uso único para vitrectomía recicladas en la práctica asistencial

O objetivo deste estudo foi avaliar o crescimento microbiano em sondas para vitrectomia de uso único, reprocessadas na prática assistencial. Foram investigadas nove sondas reusadas e reprocessadas por diferentes métodos. As sondas foram segmentadas, individualmente, em porções de 3,5 cm, totalizando em 979 unidades amostrais (extensões, conectores e ponteiras) inoculadas em meio de cultura e incubadas a 37ºC, por 14 dias. Os resultados mostraram crescimento microbiano em 57 (5,8%) unidades amostrais, das quais, 25 foram esterilizadas por Óxido de Etileno, 16 por Plasma de Peróxido de Hidrogênio e 16 por Vapor à Baixa Temperatura e Formaldeído. Foram identificadas 17 espécies microbianas, sendo as mais prevalentes o Micrococcus spp., Staphylococcus coagulase negativa, Pseudomonas spp. e Bacillus subtilis. O reuso de sondas de uso único para vitrectomia não se mostrou seguro, portanto tal prática não é recomendada.

The aim of this study was to evaluate the microbial growth on single-use vitrectomy probes reprocessed in healthcare practice. We investigated nine vitrectomy probes that had been reused and reprocessed using different methods. The samples were sectioned, individually, in portions of 3.5 cm, totaling 979 sampling units (extensions, connectors and vitrectomy cutters), which were inoculated in culture medium and incubated at 37ºC for 14 days. The results showed microbial growth on 57 (5.8%) sample units, 25 of which had been sterilized using ethylene oxide, 16 by hydrogen peroxide plasma, and 16 by low-temperature steam and formaldehyde. Seventeen microbial species were identified. The most prevalent were: Micrococcus spp., coagulase-negative Staphylococcus, Pseudomonas spp., and Bacillus subtilis. The reuse of single-use vitrectomy probes was shown to be unsafe, therefore this practice is not recommended.

Este estudio objetivó evaluar el crecimiento microbiano en sondas para vitrectomía de uso único recicladas en la práctica asistencial. Se investigaron nueve sondas reutilizadas y recicladas mediante diferentes métodos. Las sondas fueron segmentadas individualmente en porciones de 3,5 cm, totalizándose 979 unidades de muestra (extensiones, conectores y punteras), inoculadas en medio de cultivo e incubadas a 37ºC por 14 días. Los resultados demostraron crecimiento microbiano en 57 (5,8%) unidades de muestra, 25 de las cuales habían sido esterilizadas con óxido de etileno, 16 con plasma de peróxido de hidrógeno y 16 por vapor a baja temperatura y formaldehido. Se identificaron 17 especies microbianas, prevaleciendo el Micrococcus spp, Staphylococcus couagulasa negativo, Pseudomonas spp y Bacillus subtilis. La reutilización de sondas de uso único para vitrectomía no demostró seguridad, por lo que la práctica no es recomendable.

Perspective on fluid and solid dynamics in different pars plana vitrectomy systems.

PURPOSE: To summarize current concepts and recent data from the literature about different vitrectomy machines and small-gauge systems based on physical laws. DESIGN: Interpretive essay. METHODS: Review and synthesis of selected recent literature with interpretation and perspective. RESULTS: Pars plana vitrectomy can be performed with a wide variety of treatment strategies, for multiple diseases, and with different materials (solids and fluids). We discuss a variety of machines and system settings (peristaltic pump, duty cycle, aspiration, and infusion controls) targeting safer and the most effective surgery with detailed explanations of the physical properties. CONCLUSIONS: Effective management of new surgical strategies is based on recognizing and addressing various physical characteristics in disease and ocular settings. Although the properties of machine are expanding, the long-term efficacy and safety of most new approaches have yet to be established in controlled clinical trials.

Perfluorocarbon liquid vitreous delamination and wide-angle viewing system in the management of complicated diabetic retinal detachment.

PURPOSE: The authors used perfluorocarbon liquid (PFCL) and a wide-angle viewing system (WAVS) to evaluate their efficacy on tractional and combined tractional/rhegmatogenous retinal detachment (RD) secondary to proliferative diabetic retinopathy (PDR). METHODS: In a prospective, noncomparative, interventional study, 76 consecutive cases of severe PDR with tractional and combined tractional/rhegmatogenous RD were submitted to vitrectomy en bloc excision technique using a WAVS and delamination with PFCL between July 1999 and December 2003. None of the patients had had previous retinal photocoagulation treatment. Preoperative characteristics, intraoperative findings, and procedures as well as postoperative results were recorded. Main outcome measures included visual acuity (VA) and rates of retinal reattachment and complications. RESULTS: After 1 to 4 years of follow-up (mean 34.3 months), the number of patients changed from 3 (3.95%) to 11 patients (14.47%) in the > or =20/40 VA range, from 12 (15.79%) to 7 (9.21%) in the 20/50 to 20/200 group, and from 61 (80.26%) to 58 (76.31%) in the < or =20/400 group, preoperatively and postoperatively, respectively. The mean final VA improved from 1.2 log-MAR before surgery to 0.89 after vitrectomy (p=0.001). This modified technique resulted in less bleeding during surgery, a better identification of intraocular structures, faster retinal reattachment, subretinal fluid reabsorption, and easier dissection of fibrovascular membranes, among other benefits. CONCLUSIONS: PFCL and WAVS appear to reduce intraoperative complication rates in the management of complicated cases of tractional and combined tractional/rhegmatogenous RD secondary to PDR. Retinal reattachment and functional vision rates improved after this technique.

Fluid dynamics in three 25-gauge vitrectomy systems: principles for use in vitreoretinal surgery.

PURPOSE: To compare infusion and extrusion fluid volumes with three 25-gauge vitrectomy systems. METHODS: The infusion and aspiration rates of 25-gauge systems from Alcon (Fort Worth, TX, USA), Bausch & Lomb (St Louis, MO, USA), and the Dutch Ophthalmic Research Centre (DORC, Zuidland, the Netherlands) were measured in vitro using balanced saline solution with different heights (40, 60, 80, 100, 120 cm) of infusion bottle, cutter velocities (800, 1100, 1500 cuts/ min) and aspiration powers (100, 200, 300, 400, 500 mmHg). RESULTS: The infusion flow velocities differed among the systems (p < 0.001 for all comparisons [p-values 0.0009-0.0001]). The aspiration rates of the Alcon and Bausch & Lomb systems were lower than that of the DORC system (p < 0.02 for all comparisons [p-values 0.018-0.002]). CONCLUSIONS: Infusion and extrusion fluid rates differ among 25-gauge vitrectomy systems. These results may help to optimize ideal aspiration and infusion parameters among 25-gauge vitrectomy systems used to treat vitreoretinal diseases.

25-gauge lens-sparing vitrectomy for stage 4A retinopathy of prematurity.

PURPOSE: To evaluate the feasibility of performing lens-sparing vitrectomies using 25-gauge instruments for the management of stage 4A retinal detachments in Retinopathy of Prematurity (ROP). METHODS: 13 eyes of 10 patients with stage 4A retinal detachments underwent a lens-sparing pars plicata vitrectomy. All patients were operated using a three port transconjunctival 25-gauge sutureless technique. The sclerotomies were made 0.5 to 1.0 mm posterior to the limbus through the pars plicata. Core vitrectomy and membrane peeling were performed. A partial fluid-air exchange was used at the end of the procedure in the majority of the cases. The anatomic status of the retina was determined by ophthalmoscopy during routine follow up visits or under general anesthesia. Per-operative complications were recorded. RESULTS: Eight of the infants were female and two were male. The average postmenstrual age at birth was 26.4 weeks and the average postgestational age at time of surgery was 39.3 weeks (range, 33-44). Three out of the 13 eyes (23%) had zone I ROP. With a mean follow-up of 17 months (range, 4-36) 12 out of the 13 eyes (92%) achieved successful retinal reattachment. One eye developed post operative hypotony with a small choroidal detachment that resolved spontaneously. CONCLUSIONS: Surgical intervention with a three port 25-gauge transconjunctival sutureless vitrectomy is an effective technique to attach the retina in patients with stage 4A retinal detachment in ROP.

Intraocular pressure rise during 25-gauge vitrectomy trocar placement.

PURPOSE: Small-gauge vitrectomy has been used to treat various vitreous and macular pathologies. Trocar/cannula insertion may raise intraocular pressure (IOP) to the point it might become detrimental to the eye, especially in the setting of open-globe trauma and eyes with severe vascular compromise. We propose to determine the magnitude of this IOP rise and its possible implications. METHODS: Three different settings were designed to measure IOP rise during trocar placement for 25 ga vitrectomy (TSV); water-column manometry was performed during trocar placement in pig eyes. Electronic applanation tonometry was recorded in human eyes undergoing 25-ga vitrectomy for macular pathology during trocar placement, and wound behavior was recorded during trocar placement in harvested dog eyes with a previously sutured corneal wound. RESULTS: The pressure recorded during trocar placement was 57.5 mmHg in pig eyes and 63.7 mmHg in human eyes. Sutured corneal wounds in dog eyes showed wound leakage and tissue incarceration during trocar insertion. CONCLUSIONS: The 25-ga vitrectomy system may have limited usefulness in the setting of open-eye trauma and compromised bloodflow, due to the elevated pressures reached during trocar placement.

20-gauge transconjunctival pars plana vitrectomy.

This article describes a transconjunctival technique for pars plana vitrectomy using 20-gauge instruments. Sclerotomies are performed directly through the conjunctiva, Tenon's capsule, and sclera with a 19-gauge microvitreoretinal blade. A sutureless 20-gauge infusion cannula is then inserted and pars plana vitrectomy is performed in a standardized fashion using 20-gauge instruments. Each sclerotomy and its corresponding conjunctival incision is closed with a single stitch using a 7-0 polyglactin suture. This transconjunctival technique is a reasonable alternative surgical approach to minimize surgical trauma of tissues (eg, conjunctiva) and hasten postoperative recovery without the additional risks and costs associated with 25-gauge pars plana vitrectomy.

Iridectomy of the anterior iris stroma using the vitreocutter during phacoemulsification in patients with iridoschisis.

We present a technique to manage iridoschisis. This technique for anterior iridectomy of the affected iris fibers avoids intraoperative obstruction of the phaco tip and prevents postoperative complications such as corneal decompensation and glaucoma. Before the capsulorhexis is created, a vitreocutter is inserted in the anterior chamber and used to cut the iris strands at the site of the iridoschisis, making an anterior sectorial stromal iridectomy and preserving the iris pigment epithelium. Phacoemulsification is then performed. After the pupil is constricted with carbacol, remnants of the loose anterior iris fibers are excised with the vitreocutter and the scleral incision is sutured.

Ultrasonography and ocular trauma [abstract]

Blunt or perforating trauma can cause considerable damage to both the anterior and posterior segment of the eye. Since the media are often opaque following trauma, the extent of the damage may be difficult to assess with routine examination. Ultrasonography can reveal hidden pathology and is often helpful in deciding upon the proper line of treatmemt. In post-contusional trauma without an open globe, full ultrasonographic investigation, including immersion techniques, can be performed. On the contrary, after perforation lesions, an exploratory B-scan can be used for locating an intraocular foreign body in addition to gross assessment of the damage. The ultrasonographic examination can only be continued in further detail after primary closure of the wound. When an x-ray of the orbit reveals the presence of an intraocular foreign body B-mode ultrasonography is superior to the Comberg-Pfeiffer method and computer tomography for precise localizations of the object and for detection of collateral damage. Transpalpebral echography or scans with the probe directly applied to the eye, at significantly reduced sensitivity levels (-20 or -30 dB) are the methods of choice for tracing a foreign body in the posterior segment or orbit. Lowering the sensitivity settings will also improve the accurate location of the foreign body. The immersion technique is used when the foreign body is located anteriorly in the eye, providing that the entry wound is closed. In particular after contusional injuries, ultrasound biomicroscopy (UBM) can be used for detailed observations of the cornea, anterior lens, chamber angle and ciliary body. Recession of the angle, subluxation of the lens and dialysis of the iris or ciliary body can be diagnosed with relative ease. When vitrectomy is indicated either as a primary or secondary procedure following ocular trauma, ultrasonography is essential in the preoperative evaluation. It will help in deciding upon the length of the preoperative period, the estimated duration of the operation and the appropriate surgical approach. A full anatomical analysis can be obtained by systemically assessing the biometric, topographic, kinetic and quantitative characteristics of the various parts of the eyes. The most commonly occuring ocular pathology following trauma, along with the most suitable diagnostic ultrasonic techniques will be discussed in detail and are depicted in the table. (AU)

Sistemas de vitrectomia de grande angular: estudo comparativo / Wide angle vitrectomy viewing systems: a comparative study

Comparou-se o uso de três equipamentos ópticos disponíveis comercialmente para a realizaçäo de vitrectomias com o uso de lentes de grande angular, durante a realizaçäo de vitrectomias via pars plana. Os equipamentos utilizados foram: Advanced Visual Instruments (A VI), que requer o uso de lente de contato (C) corneana; o binocular Indirect Ophthalmomicroscope System (BIOM), composto de dois sistemas, um sistema de contato (BIOMC) e um sistema de näo contato (BIOM-NC); e o Erect Indirect Ophthalmscop System (EIBOS), que é um sistema de näo contato. Foram identificados catorze parâmetros para a avaliaçäo de cada um destes sistemas em vitrectomias realizadas em 16 olhos de 8 coelhos adultos pigmentados, da mesma raça e cor. Cada parâmetro foi classificado ..