Vitrectomy System Research Articles

Heads-up 3-dimensional-visualization system and integrated intraoperative optical coherence tomography in infantile vitreoretinal surgeries

ObjectiveTo demonstrate initial experience of Heads-up 3-dimensional-visualization system and integrated intra operative optical coherence tomography (iOCT) in a spectrum of complex infantile vitreoretinal surgeries. MethodsTwo different 3-D-visualization systems were used during the surgery on case-to-case basis and iOCT was used as needed. The vitrectomy system used was the same for all the surgeries. The disease spectrum included retinal disorders due to retinopathy of prematurity, familial exudative vitreoretinopathy, and retinitis. DesignDescriptive case series of surgeries operated under 3-D visualization and conventional microscope. ResultsA total of 10 eyes of 7 patients were included; out of which 5 eyes of 4 unique cases were operated under 3-D-visualization system and remaining 5 eyes of other 3 cases under the conventional microscope. The cases present our initial experience of the 3-D visualization and iOCT system over the conventional microscope with appropriate imaging and surgical videos. ConclusionInfantile vitreoretinal surgeries are difficult to teach, require an ergonomic friendly surgical environment and unpredictable surgical adjustments, which are the chief advantages of the discussed technologies. Heads-up 3-D-visualization system and iOCT appeared to be powerful new tools that can be explored further for use in complex infantile vitreoretinal surgeries.

Liquid-Driven Microinjection System for Precise Fundus Injection.

Microinjection is usually applied to the treatment of some retinal disorders, such as retinal vein cannulation and displaced submacular hemorrhage. Currently, the microinjection procedure is usually performed by using the viscous fluid control of a standard vitrectomy system, which applies a fixed air pressure through foot pedal activation. The injection process with the fixed pressure is uncontrollable and lacks feedback, the high flow rate of the injected drug may cause damage to the fundus tissue. In this paper, a liquid-driven microinjection system with a flow sensor is designed and developed specifically for fundus injection. In addition, a PID sliding mode control (SMC) method is proposed to achieve precise injection in the injection system. The experimental results of fundus simulation injection demonstrate that the microinjection system meets the requirements of fundus injection and reduces the impact of the injection process on the fundus tissue.

Infusion-Assisted Evacuation of Submacular Hemorrhage.

To report a novel surgical technique for evacuating submacular hemorrhage using the infusion stream of a 25 gauge vitrectomy system. Surgical case and video. A 54 year old male was taken to the operating room for a total hyphema, non-clearing vitreous hemorrhage, and elevated intraocular pressure after multiple tractional retinal detachment repairs by an outside surgeon. Intraoperatively the hyphema and vitreous hemorrhage were cleared, and the source of bleeding was discovered to be an avulsed vessel through a pre-existing retinal break just superior to the optic nerve. A large submacular hemorrhage was also present that was unable to be drained through the break by aspiration alone. With the vitreous cavity under fluid, the infusion cannula was manipulated to guide the infusion stream onto the macula. The stream was directed in a distal to proximal manner towards the retinal break, and the submacular blood was successfully expressed out through the break. Postoperatively the retina remained attached with almost complete resolution of the submacular hemorrhage. Utilizing the mechanical pressure of the infusion stream can be an effective method for evacuating large subretinal hemorrhages.

Geuder Megatron S4 HPS System

The closed vitrectomy system, which was first described by Machemer in 1971, is the most frequently applied method in the treatment of vitreoretinal pathologies, especially with the developments in vitrectomy systems in the last decade. Today, safe, fast and effective vitreoretinal surgery is possible thanks to the use of microincisional instruments. In this article, technical information about Megathron S4 HPS vitrectomy system, which is one of the current systems, is explained.

General Advantages and Disadvantages of 20, 23, 25 and 27 Gauge Vitrectomies

Over the last half-century, vitreoretinal surgery has evolved from 20-gauge to 23-, 25- and 27-gauge vitrectomy, also known as micro-invasive vitrectomy, with the development of technology and instrumentation. The most important difference of 20-G vitrectomy from other systems is that it creates a larger sclerotomy and therefore requires sutures. Although its large diameter is an advantage depending on the surgical indication, the necessity of sutures also brings disadvantages. On the other hand, micro-invasive vitrectomy systems usually do not require sutures due to their smaller diameter, and suture-related complications are not encountered. Other important advantages are that they can also be used in complex vitreoretinal surgeries. Although they have lower infusion and aspiration rates compared to 20-G vitrectomy as a result of their small diameter, each system has advantages and disadvantages depending on the surgical indication used. This review aims to comparatively present the general advantages and disadvantages of the 20-, 23-, 25- and 27-gauge vitrectomies.

Opticon Vitrectomy System

The Opticon vitrectomy system is a safe and efficient unit used for anterior and posterior segment surgical procedures. The device is designed to perform phacoemulsification, irrigation/aspiration, anterior and posterior vitrectomy, making air/silicone tamponade, intraocular illumination and bipolar diathermy coagulation procedures.

Vitrectomy Devices: Bausch & Lomb Stellaris PC System and Bausch & Lomb Vitesse Hypersonic Vitrectomy

Considering that the beginning of modern vitrectomy is thought to date back to the 1970s, the progress made in vitreoretinal surgery in such a short period of time is remarkable, thanks to the dedication of surgeons and advancements in technology. There have been developments that have allowed for more practical, safer, and more effective surgeries with wider indications. These advancements have not only been seen in vitrectomy probes that tend to be smaller, faster, and safer, but also in all other instrumentation. In 2010, the Bausch & Lomb Stellaris PC system joined the vitreoretinal surgery family. The updated Stellaris Elite device in 2017, along with the Vitesse Hypersonic vitrectomy system introduced to our practice, has been revolutionary after years of using pneumatic guillotine vitrectomy. The aim was to explain the recent developments that have been incorporated into our practice through this system.

Synergetics Versavit 2.0 Vitrectomy System

The Synergetics VersaVIT 2.0 (Bausch and Lomb) unit has been introduced as a portable system that can be easily moved from the operating room to the office environment and can also run on battery power. Although the VersaVIT 2.0 system is frequently preferred for uncomplicated and long-lasting cases such as vitreous hemorrhage, vitreous condensation, epiretinal membrane, and macular hole, especially in private practice and outpatient surgery centers, complicated vitreoretinal surgeries can also be performed with the system. The installation of the system is provided in a very short time, such as 10 seconds, and due to its simplicity of use, it is possible to perform surgery with personnel who do not have vitrectomy training. VersaVIT 2.0® is a unique portative vitrectomy system that has a cut rate of 6000 cpm. The entire unit is quite light. It can run on electric current power or up to 60 minutes on a rechargeable internal battery. This system includes the entire vitreoretinal product line, including endolaser probes, endoilluminators, chandeliers, and packs. It allows working with 23, 25, and 27g trocar systems and product bases. Illuminated options of laser probe, vitrector, and infusion cannula are available. Endoilluminators have options that provide both focal, Middlefield, and widefield panoramic lighting. Unlike the first model, VersaVIT 2.0 also has the option of silicone injection and removal features. It has a new trocar system for faster and more practical application. Special trocars are available for pediatric cases. VersaVIT 2.0 is a vitrectomy machine that is portable due to its small size and is preferred in selected cases and also allows advanced vitreoretinal surgeries with its sufficient fluidity and good cutting properties.

Features of Zeiss Visalis V500 Combined Phacoemulsification and Vitrectomy Device

Rapid developments in today's technology have led the rapid evolution of devices in the field of eye surgery. Old technology devices that take up space and are difficult to use have been replaced by more user-friendly, compact devices. In this review, we aimed to talk about the features of the Zeiss Visalis V500 device, which is produced as a compact device and has a vitrectomy system integrated with phacoemulsification technology.

Novel Technique for 27-Gauge Forceps-Assisted Transscleral Refixation of the Dislocated CZ70BD Intraocular Lens.

To report a novel technique for refixation of the dislocated CZ70BD intraocular lens. Posterior vitrectomy is performed with a 23-gauge or 25-gauge pars plana vitrectomy system with chandelier illumination. One needle of a double-arm 9-0 prolene needle is passed through the sclera 1.5 mm postlimbus. The needle is retrieved through the corneal paracentesis using a 27-G needle, and the suture is then cut. The suture end is passed through the eyelet of the dislocated CZ70BD intraocular lens inside the vitreous cavity. This is aided with a pair of 27-G MaxGrip forceps, which is inserted through a 27-G sclerostomy site at the intended scleral outlet. After passing the suture through the eyelet, the suture is pulled out at the 27-G sclerostomy site and a knot is tied and rotated. Similar procedure is performed for the second haptic if necessary. Seven eyes were successfully operated on using this technique with a mean follow-up of 12.4 months. There was significant improvement in the best-corrected visual acuity after the operation ( P = 0.016). Postoperative intraocular lens centration and alignment were satisfactory. One patient developed macula-on retinal detachment 1 month after the operation, which was successfully repaired without loss in the best-corrected visual acuity. The described novel technique is effective for refixation of dislocated CZ70BD intraocular lens.

Use of a Backflush Needle with a Silicone Tip Cannula to Embed Lamellar Hole-Associated Epiretinal Proliferation.

For the treatment of lamellar macular hole, the recent development of a lamellar hole-associated epiretinal proliferation (LHEP) embedding technique is likely to improve functional and anatomical results. However, the peeling of LHEP is often technically challenging. We have developed a new technique using a backflush needle with a silicone tip cannula that seems safer and more effective for use in LHEP embedding. A 25-gauge vitrectomy system with an enhancing visual acuity system (D.O.R.C., Zuidland, Netherlands) was used in all cases. After core vitrectomy, triamcinolone acetonide (Wakamoto Pharmaceutical Co., Ltd., Tokyo, Japan) was used to visualize the membrane. A 25-gauge backflush needle with a silicone tip cannula was used to remove the thin preretinal membrane centripetally, leaving an LHEP on the edge of the hole. Brilliant Blue G (internal limiting membrane Blue; D.O.R.C.) was then used to stain the internal limiting membrane. This technique was used in six eyes with lamellar macular holes. In all cases, peeling and embedding of the LHEP was effectively performed without damaging the internal limiting membrane or causing retinal hemorrhage. No other intraoperative or postoperative complications were experienced. Using a silicone-tipped backflush needle with passive aspiration was a simple and effective technique for peeling and embedding of LHEPs in this small series.

A comparative study of anatomical and functional outcomes after 20, 23 and 25 gauge pars plana vitrectomy in adult population at a tertiary care center in Rajasthan

Pars plana vitrectomy is the most common technique in vitreoretinal surgery that enables access to the posterior segment for treating conditions such as retinal detachment, vitreous hemorrhage, macular hole, endophthalmitis, dropped nucleus and dropped iol in a controlled closed system.Prospective, comparative study of patients, more than 18 years of age, who underwent pars plana vitrectomy for various vitreoretinal disease at J.L.N. Medical College, Ajmer, from October 2020 to March 2022,with no previous history of any vitreoretinal surgery.96 eyes of 96 patients that underwent 20-gauge (n=32), 23-gauge (n=32) and 25-gauge (n=32) Pars plana vitrectomy were included in this study. The mean duration of surgery was significantly higher in the conventional 20-Gauge as compared to the micro incisional vitrectomy system. Mean Best corrected visual acuity (BCVA) improved significantly in all three groups at postoperative 3 months, no significant difference between the 3 groups. Re retinal detachment occurs in 6 eyes(2 eyes in each group). Recurrent vitreous hemorrhage occurs in 1 eye in 25-gauge and postoperative endophthalmitis occurs in 2 eyes(1 eye each in 20-gauge and 23-gauge). There was a similar rate of ocular hypertension in all three groups. Postoperatively 20-gauge showed significantly higher mean conjunctival hyperemia and subconjunctival hemorrhage compared to Sutureless microincisional vitrectomy surgery.Functional and anatomical outcomes assessed by BCVA and retinal status postoperatively seem to be comparable between 20,23 and 25-gauge vitrectomy systems. Sutureless microincisional vitrectomy surgery showed significantly shorter duration of surgery.

27‑Gauge vitrectomy vs. 25‑gauge vitrectomy in the management of proliferative diabetic retinopathy with preoperative intravitreal injection of conbercept.

Small-gauge vitrectomy has become popular due to its notable advantages, including less trauma, shortened convalescence and improved manoeuvrability. The aim of the present study was to compare the surgical outcomes of 27-gauge (27-G) vitrectomy with those of 25-gauge (25-G) vitrectomy in the management of proliferative diabetic retinopathy (PDR) with preoperative intravitreal injection of conbercept. The data of 48 consecutive patients with PDR (48 eyes) were retrospectively collected. The patients underwent conbercept intravitreal injection and pars plana vitrectomy with a 27-G group (23 eyes) or 25-G group (25 eyes) vitrectomy system. The operating time, suturing rate, endodiathermy rate, postoperative best-corrected visual acuity (BCVA), intraocular pressure (IOP) and complications were recorded. The mean postoperative BCVA at final follow-up was significantly improved compared with that at the baseline in both groups (P<0.001 for both). The differences in the mean BCVA changes between the two groups were not significant (P>0.99), and no differences were observed in the final central foveal thickness (P=0.51) between the two groups. The final IOP remained stable compared with that at the baseline in the 27-G group (P=0.36) and the 25-G group (P=0.05). The suturing rate was significantly decreased in the 27-G group compared with the 25-G group (P=0.04). There were no significant differences between the two groups in terms of the operating time (P=0.18), rate of endodiathermy use (P>0.99), iatrogenic retinal breaks (P=0.42) or postoperative recurrent vitreous haemorrhage (P>0.99). In addition, no case of ocular hypotony was observed in either group. In conclusion, 27-G vitrectomy was as efficient and safe as 25-G vitrectomy in the management of PDR in terms of operating time and complications. With reference to the literature, preoperative conbercept injection appears to assist in decreasing the incidence of intraoperative and postoperative complications.

Paediatric cataract surgery with 27G vitrectomy instrumentation: the Ghent University Hospital Experience.

To describe a cohort of paediatric patients who underwent unilateral or bilateral lens extractions at Ghent University hospital using the Dutch Ophthalmic Research Center (D.O.R.C.) ultra-short 27G vitrectomy system. Retrospective analysis of the medical and surgical records of all children that underwent lens extraction between September 2016 and September 2020 using the D.O.R.C. ultra-short 27G vitrectomy system. Seventy-two eyes of 52 patients were included. The most important aetiologies in this study were of secondary (25.5%), developmental (13.7%), or genetic (13.7%) nature. No definitive cause could be established in more than a quarter of cases (27.5%) despite extensive work-up, them being deemed idiopathic. The remainder of cases (19.6%) was not assigned a final aetiologic designation at the time of the study due to contradicting or missing diagnostic data. This study could not identify any cataract cases related to infection or trauma. Surgical complications rate was 61.1% of which posterior capsule opacification was the most frequent with a rate of 25%. A significant short-term postoperative best-corrected visual acuity gain (≤ -0.2 LogMAR) was observed in 60.5% of eyes for which usable acuity data were available (n = 38). Many different instruments and techniques have been described and used in the context of paediatric lens extractions, each with its advantages and disadvantages. This study illustrates that an ultra-short 27G vitrectomy system can be used to perform paediatric lens extractions with good surgical outcomes. Further studies and comparative trials are needed to ascertain this further.

DIAGNOSTIC YIELD OF IN VITRO VITREOUS BIOPSY FOR INTRAOCULAR LYMPHOMA AT VARIABLE VITREOUS CUTTER SPEEDS USING 25-GAUGE VITRECTOMY.

Primary vitreoretinal lymphoma is the most common intraocular lymphoproliferative disorder. We evaluated the diagnostic yield of pars plana vitrectomy, specifically using modern high cut rate dual-cycle cutters, on in vitro cell viability and diagnostic yield. Human Burkitt lymphoma cell line Namalwa at 2 x 10^5 cells/mL was aspirated by 25-gauge dual-blade guillotine-type vitrectomy at five speeds (500, 1,000, 4,000, 7,500, or 15,000 cuts per minute). Cell viability and diagnostic yield in each subtype group were determined using hemocytometry, viable cell count using Cell Counting Kit-8, and pathologist-guided manual count. No significant deviation in cell count was identified in any cut rate by ANOVA ( P = 0.61), and no trends in the number of viable cells were identified across cut rates (R 2 = 0.188, P = 0.47). Among histologic cell counts per cut-rate, neither linear regression (R = 0.531, P = 0.16) nor ANOVA ( P = 0.096) were statistically significant. There was no significant degradation in the number of viable cells with increasing cut speed. These results suggest that in contrast to previous findings using 20g or 23g vitrectomy for diagnostic vitrectomy, modern vitrectomy systems may be used at up to 15,000 cpm without compromising the viability of lymphoma cells.

Hypersonic vitrectomy in intraoperative posterior capsular rupture with retained nuclear fragments.

In our report, we present the hypersonic vitrectomy (Vitesse, Bausch and Lomb) being employed for anterior vitreous liquefaction and removal in posterior capsular rupture. The capsular tear with nucleus drop during conventional phacoemulsification was managed by vitrectomy using the hypersonic vitrector after posterior-assisted levitation followed by intraocular lens (IOL) implantation. The minimal cortical and epinuclear lens particles in the anterior chamber and vitreous were also liquefied with a stoke length of 30 to 40 μm and aspirated via the Vitesse vitrectomy system. The same probe performs the vitrectomy and the nucleus removal. The postoperative period was uneventful with clear cornea, normal fundus, and 20/20 best-corrected visual acuity (BCVA). The hypersonic vitrectomy utilizes the ultrasound power of 29.5 kHz and a stoke length of 0 to 60 μm for liquefaction of the vitreous. It can be a safe alternative for vitrectomy and lens removal in a single setting.

Small Gauge Techniques for Removing a Fluocinolone Acetonide Implant.

Long-acting injectable fluocinolone releasing implants are used in clinical practice. While limited in scope, situations may arise where removal of the implant is warranted. We set out to describe possible explantation techniques and to determine whether these implants can be safely removed from a standard sclerotomy or eliminated using a vitrectomy system. A vitreoretinal surgery system was designed using a porcine eye model. A fluocinolone implant was injected into the vitreous cavity. Pars plana vitrectomy was performed and the vitreous cavity was infused with balanced salt solution. The injected implants were removed from 23-Gauge (G) and 25-Gauge (G) vitrectomy cannulas with 27-G forceps. The implants were examined under the microscope for induced defects. Implants were injected into the eye model and eliminated using a 23-G and 25-G vitrector system. The implant was removed from both the 23-G and 25-G vitrectomy cannulas with only mild structural damage to the implant. During implant extraction through the 25-G sclerotomy, the cannula was dislodged from the incision along with the implant. The most technically challenging portion involved aligning the implant coaxially to allow for removal en bloc through the sclerotomy site. Implants could be eliminated using both the 23-G and 25-G vitrector using a low-cut rate. The fluocinolone implant was removed safely via standard 23-G or 25-G vitrectomy systems. It is unknown whether intraocular manipulation will affect pharmacokinetics of drug delivery if the implant is not explanted.

Hypersonic vitrectomy: a novel approach to vitreous removal

ABSTRACT Introduction Pars plana vitrectomy is the basis of modern retina surgery, and for the last 40 years, has been achieved using the pneumatic guillotine cutter. Recently, a new vitrectomy design has been developed: the hypersonic vitrector. This technology utilizes ultrasound energy to liquefy vitreous in contrast to the mechanical segmentation of vitreous strands that characterizes pneumatic cutters. Areas covered This review provides a history of the development of vitrectomy and summarizes the critical elements of effective and safe vitrectomy systems. The article will describe the novel hypersonic vitrectomy design, discuss what the initial pre-clinical and in-human studies tell us about its performance compared to standard pneumatic cutters, and considers its role in the future of retina surgery. Expert opinion Hypersonic vitrectomy is the first novel way to segment vitreous since the development of pneumatic guillotine cutters. It has the potential to make vitrectomy more efficient both by reducing operating times as well as enabling surgeons to remove silicone oil and retained lens material all with one instrument. With concurrent advancements in guillotine cutters, hypersonic vitrectomy has a high bar to clear to demonstrate advantages that would result in widespread adoption.

Advances in Vitreoretinal Surgery.

Advances in vitreoretinal surgery provide greater safety, efficacy, and reliability in the management of the several vitreoretinal diseases that benefit from surgical treatment. The advances are divided into the following topics: scleral buckling using chandelier illumination guided by non-contact visualization systems; sclerotomy/valved trocar diameters; posterior vitrectomy systems and ergonomic vitrectomy probes; chromovitrectomy; vitreous substitutes; intraoperative visualization systems including three-dimensional technology, systems for intraoperative optical coherence tomography, new instrumentation in vitreoretinal surgery, anti-VEGF injection before vitrectomy and in eyes with proliferative diabetic retinopathy, and new surgical techniques; endoscopic surgery; the management of subretinal hemorrhages; gene therapy; alternative techniques for refractory macular hole; perspectives for stem cell therapy and the prevention of proliferative vitreoretinopathy; and, finally, the Port Delivery System. The main objective of this review is to update the reader on the latest changes in vitreoretinal surgery and to provide an understanding of how each has impacted the improvement of surgical outcomes.

Tono-pen and Schiotz tonometer measurements in gas-filled eyes

This study aims to assess the difference between Tono-Pen and Schiotz tonometer measurements in gas-filled eyes and to create a nomogram and equation which can be used to estimate actual intraocular pressure in order to provide a safe IOP level at the end of the surgery. Twenty-two eyes that underwent pars plana vitrectomy were included in the study. Perioperative Tono-Pen and Schiotz tonometer measurements were performed when the eyes were filled with air in the setting of certain vitrectomy infusion pressure levels. Measurements were performed when the eyes were filled with fluid to test the accuracy of the systems. The mean value of the Tono-Pen and Schiotz readings in air-filled eyes corresponding to certain actual intraocular pressure levels were analyzed to create nomograms. Both Tono-Pen and Schiotz tonometers underestimated the actual intraocular pressure set on the screen of the vitrectomy system in the air-filled eyes. The Tono-Pen deviation was 4.5mmHg at a level of 15mmHg actual intraocular pressure, and 16.9mmHg at a level of 55mmHg actual intraocular pressure. The Schiotz tonometer deviation was 10mmHg at a level of 15mmHg actual intraocular pressure, and 8.9mmHg at a level of 55mmHg actual intraocular pressure. All the mean differences between tonometer readings and actual intraocular pressure were statistically significant. (P<0.001) CONCLUSION: To achieve an adequate and safe tamponade at an actual IOP range of 20 - 25mmHg, one should adjust the IOP with Schiotz readings to a level of 9-12mmHg, or Tono-Pen readings to 12-18mmHg.