Real-life comparison of the viewing angle and the image quality of two commonly used viewing systems for vitreoretinal surgery

Background/aim: To compare the clinical use, image quality and viewing angle of a commonly used contact wide angle viewing (WAV) system (Advanced Visual Instruments (AVI) Panoramic Imaging Systems, NY, USA) with a commonly used noncontact WAV system (Leica RUV800, Leica Microsystems, Switzerland). Materials and methods: Images of 42 consecutively operated eyes were obtained with both systems at the same surgical stages and were compared for image quality using the Imatest Master 4.5.13 (Imatest LLC, Boulder, USA) software. The viewing angles of the images were calculated using the optic disc sizes measured from the OCT and infrared fundus images. The 68-degree AVI lens was compared with the 90-dioptre (D) Leica RUV800 lens, while the 130-degree AVI lens was compared with the 132-D Leica RUV800 lens. The surgical assistants were asked to grade the difficulty of holding the lens in place from 1 to 10, 1 being the easiest and 10 being the most difficult. Results: The contact system provided wider viewing angles with higher quality compared to the noncontact system both under fluid and air media. The difference was clinically significant in eyes with impaired corneal clarity, very high myopia, or small pupil. The difficulty of holding the lens in place ranged from 4 to 7, and decreased gradually with practice. Conclusions: Both WAV systems provided high image quality and adequate viewing angles in most cases. However, the contact system appeared to provide a superior image quality and/or a wider viewing angle in more challenging situations. The difficulty of holding the contact lens in place was found to be moderate.

RESOLUTION, DEPTH OF FIELD, AND PHYSICIAN SATISFACTION DURING DIGITALLY ASSISTED VITREORETINAL SURGERY.

PURPOSE: To evaluate depth of field, lateral resolution, and image quality of a heads-up 3D visualization system for vitreoretinal surgery using physician survey and optical measurement outcomes. METHODS: Depth of field and lateral resolution were compared between the standard ocular viewing system and the digital 3D system at ×5, ×13, and ×18 magnification by 6 retinal surgeons. Optical techniques were used as well as a survey of surgeon impression. Surgeon impression surveys were performed after 6 weeks of surgical use of the device. RESULTS: Physician questionnaire survey scores for depth of field at high magnification were better for the digital 3D system and equivalent for all other categories. Measured lateral resolution was 36.7 mm and 16.6 mm at ×5 magnification (P < 0.001), 14.3 mm and 6.4 mm at ×13 magnification (P < 0.001), and 9.8 mm and 4.2 mm (P < 0.001) at ×18 magnification for the digital 3D and oculars, respectively. Measured depth of field was 4.00 mm and 6.78 mm at ×5 magnification (P = 0.027), 0.72 mm and 0.86 mm at ×13 (P = 0.311), and 0.28 mm and 0.40 mm at ×18 magnification (P = 0.235) for the oculars and digital 3D, respectively. CONCLUSION: Lateral resolution of the digital 3D system was half that of the ocular viewing system and there was some improvement in depth of field with the digital system. Surgeon impression suggested that the digital system was superior when evaluating depth of field at high magnification.

Retinal Toxicity of Medical Devices Used during Vitreoretinal Surgery: A Critical Overview.

Retinal toxicity/biocompatibility of medical devices in direct contact with the retina is an important subject for clinicians and scientists. As these effects are not very frequent, there is also a relative lack of information for many clinicians. The past has taught us multiple times that there is a significant safety problem associated with severe loss of vision in affected patients. In this review, we want to classify medical products that are used in the back of the eye, describe recent examples of toxicity, critically reflect on the regulations that exist and suggest improvements that can be done to ensure patient safety without hindering innovation. METHODS: Critical review of the recent papers and personal experience of the authors in this issue. Medical devices used in the back of the eye and recent examples of toxicity are described, regulations that exist are critically reflected and improvements suggested that can ensure patient safety without hindering innovation. RESULTS: There is clear evidence of toxicity after intraocular surgery in any category. Some cytotoxic indirect methods have failed in detecting this toxicity. Some ISO rules do not seem appropriate. Postmarketing safety is missing. There is little data on this issue. CONCLUSIONS: The absence of a clear regulation of the production, purification and evaluation of the toxic effects of the medical devices supposes the possibility that products are not sufficiently safe to obtain the CE mark.

Advancements of vitreoretinal surgical machines.

PURPOSE OF REVIEW: This article reviews current advancements in vitreoretinal surgical machines. RECENT FINDINGS: The most recent advancement in vitreoretinal surgical machines include 27-gauge vitrectomy probes, new cutter designs, higher cut rate, improved intraocular pressure control, new endoillumination technologies, and combined anterior/posterior segment capabilities. SUMMARY: With recent advancements in vitreoretinal surgical machines, surgical incisions have become less traumatic and fluidics control has led to a more controlled posterior segment vitrectomy.

Importance of Light Filters in Modern Vitreoretinal Surgery: An Update of the Literature.

PURPOSE: Direct endobulbar illumination during vitreoretinal surgery causes light-induced retinal damage known as phototoxicity. Spectral filters have been proposed to eliminate hazardous wavelengths from the emission spectrum before entering the eye. The purpose of our paper is to review advances in vitreoretinal surgery, focusing on intraoperative light filters. METHODS: A PubMed and Medline database search was carried out using the terms "spectral filters" associated with "vitreoretinal surgery," "phototoxicity," and "vitrectomy." Original articles, reviews, and book chapters up to March 2017 were reviewed; a few select articles published before 2000 are included for historical purposes. Material from recent meeting presentations was also added. The preferred language for the reviewed literature was English. RESULTS: Spectral filters significantly reduce the risk of phototoxicity associated with endoillumination in vitreoretinal surgery, allowing higher exposure times than with optic light fibers alone. Spectral filters may affect intraoperative luminance, but do not alter color contrast. Amber filters showed superiority over green and yellow filters. CONCLUSION: The choice of light sources coupled to spectral filters is strongly suggested, especially in dye-assisted chromovitrectomy. Histological donor eye studies and large multicenter trials are needed to validate the amount of photoprotection provided by spectral filters before a general recommendation can be made.

Clinical utility of intraoperative optical coherence tomography.

PURPOSE OF REVIEW: To explore the clinical utility of intraoperative optical coherence tomography (iOCT) for the management of vitreoretinal conditions. RECENT FINDINGS: The role of iOCT in guiding surgical decision-making and surgical manipulations during vitreoretinal procedures has been evaluated by multiple studies. This imaging modality is emerging as a valuable asset during procedures for vitreoretinal interface disorders, retinal detachments, submacular surgeries and therapeutics, and in pediatric conditions such as retinopathy of prematurity. iOCT allows the surgeon to assess completion of surgical goals and to directly monitor the architectural impact of instrument-tissue interactions that may correlate with eventual prognosis. The technology has gone through numerous iterations with the eventual goal being the development of a user-friendly, efficient, and integrated system that provides surgeons with 'real-time' feedback during ophthalmic surgeries to allow for a comprehensive image-assisted vitreoretinal surgery platform. SUMMARY: The role of iOCT in ophthalmic surgery has been evolving with the help of ongoing research to define its utility in the operating room and to develop integrative technologies. Advancements in OCT-friendly surgical instrumentation and in integrative capabilities of this technology may help achieve more widespread adoption of this technology in the vitreoretinal surgical theater. Although the evidence appears clear that this technology impacts surgical decision-making, additional research is needed. However, further research is needed to determine the influence of this technology on overall patient outcomes.

An extraocular non-invasive transscleral LED-endoilluminator for eye speculum integration.

PURPOSE: Conventional chandelier-endoilluminators used for pars-plana vitrectomy consist of a light-emitting tip attached to an optical fibre. The tip requires introduction into the ocular space through an incision. To achieve complete illumination of the intraocular space, the introduction of more than just one tip is sometimes necessary. An extraocular vitreoretinal LED-endoilluminator discussed in this paper represents a new approach to illuminate the intraocular space. The light source is integrated into a speculum and firmly apposed to the sclera. This approach offers the advantage of effectively illuminating the interior of the eye even though the procedure is non-invasive. Furthermore, this approach significantly reduces the risk of damage to the retina by phototoxic effects. METHODS: A round white LED was used as a light source. By integrating the light source into a speculum, the LED was firmly held against the sclera. Thus, the ocular space was illuminated transsclerally. As a result, indirect uniform illumination of the complete intraocular space was achieved. The prototype was developed considering the relevant international standards. Porcine eyes were used because their properties are similar to those of human eyes. RESULTS: Porcine eyes could be acceptably illuminated with the selected LED. The LED-endoilluminator conforms with international standards for endoillumination. Thus, possible photochemical and thermal risks are considered and reduced to a minimum. CONCLUSIONS: A novel LED-endoilluminator which can be attached to a speculum was developed. The system does not need any connection to an external light source and, consequently, also avoids usage of an optical fibre. Regular and uniform illumination of the intraocular space was achieved by transmitted and scattered visible irradiation, avoiding an incision. The duration of potential light exposure, compared to existing illumination systems, can be significantly increased. This is also true when the illuminator is not directly placed over the pars-plana and the distance to the retina is reduced. Only a part of the light reaches the retina and the fraction of short wavelength becomes very small. Increased safety of the system results from now being able to increase the exposure time and reduce phototoxic stress to the retina.

The value of intraoperative optical coherence tomography imaging in vitreoretinal surgery.

PURPOSE OF REVIEW: To evaluate the role of intraoperative optical coherence tomography (iOCT) in vitreoretinal surgery, assess the current state-of-the art, and to examine possible future directions in the field. RECENT FINDINGS: Numerous vitreoretinal surgical conditions and procedures have been described utilizing iOCT. These conditions include macular holes, epiretinal membranes, retinal detachments, and retinopathy of prematurity. Significant alterations appear to occur during surgical manipulations in many of these conditions that can be identified with iOCT. The most common current systems used are portable OCT probes that are either mounted to a microscope or used in a handheld fashion. Prototypes are also being utilized that are integrated into the microscope to allow for true 'real-time' imaging of instrument-tissue interactions. Current generation surgical instrument materials (e.g., metal) limit optimal visualization with integrated OCT systems because of shadowing and light scattering properties. SUMMARY: The role of iOCT in vitreoretinal surgery continues to be defined by active research and enhancements to integrative technologies. Further research is needed to better define the specific applications of iOCT that impact patient outcomes and surgical decision-making. Future advancements in integrative systems, OCT-friendly instrumentation, and software algorithms will further expand the horizon of iOCT in the vitreoretinal surgical theater. As OCT transformed the clinical management of the vitreoretinal conditions, iOCT has the potential to be a paradigm-shifting technology in the operating room.

Endoscopic vitrectomy.

PURPOSE OF REVIEW: To update on the recent developments and surgical applications of intraocular endoscopy, and highlight its role in the modern era of microincision vitreoretinal surgery. RECENT FINDINGS: Recent progress in our understanding of the unique intraocular illumination properties of endoscopy, specifically the use of reflected (coaxial) versus conventional transmitted (dissociated) light, is redefining its role in vitreoretinal surgery. Indications for endoscope-enabled intraoperative viewing during pars plana vitrectomy include posterior segment disease with significant anterior segment opacity, difficult-to-access retroirideal diseases involving the sclerotomy, pars plana, pars plicata, ciliary sulcus, ciliary body, or peripheral lens, and complex anterior retinal detachments, particularly in diseases in children. The recent introduction of 23-gauge endoscope that works with standard microcannulas increases its utility. SUMMARY: Endoscopic vitrectomy, particularly with the recent advent of 23-gauge technology, expands our surgical armamentarium, making it a useful complement to conventional viewing systems.

Use of a Novel Beyeonics One Three-dimensional Head-mounted Digital Visualization Platform in Vitreoretinal surgeries.

BACKGROUND: Ophthalmic microscopes have been crucial in visualizing surgical fields, but their limitations in enhancing the surgical view through digital image processing have prompted the development of digital surgical microscopes. The Beyeonics One microscope, a novel digital microscope, offers ophthalmic surgeons a 3D visualization platform and an augmented reality (AR) surgical headset, potentially improving surgical decision-making and outcomes. While its initial use has been described in cataract and corneal surgeries, its application in vitreoretinal surgery remains relatively unexplored. METHODS: In this interventional case series, we collected data from the medical records of patients who underwent vitreoretinal surgery using the Beyeonics One 3D visualization platform at the Tel Aviv Medical Center. A total of 36 eyes from 36 subjects were included. Surgical techniques included retinal detachment surgeries and macular surgeries, performed by experienced surgeons. The surgical visualization was facilitated by the Beyeonics One 3D head-mounted display (HMD) platform. RESULTS: The procedures were uneventful, and none intra- or postoperative complications were reported, and surgeons did not experience any signal delay in the real-time video. DISCUSSION: The Beyeonics One microscope offers several potential advantages in vitreoretinal surgery, including digital image processing, enhanced depth perception through the 3D HMD platform, and hands-free image control using head gestures. While this study demonstrates the feasibility and safety of the Beyeonics One microscope, addressing limitations related to hazy views and optimizing image quality are crucial for consistent visualization.

Active tremor cancellation by a "smart" handheld vitreoretinal microsurgical tool using swept source optical coherence tomography.

Microsurgeons require dexterity to make precise and stable maneuvers to achieve surgical objectives and to minimize surgical risks during freehand procedures. This work presents a novel, common path, swept source optical coherence tomography-based "smart" micromanipulation aided robotic-surgical tool (SMART) that actively suppresses surgeon hand tremor. The tool allows enhanced tool tip stabilization, more accurate targeting and the potential to lower surgical risk. Freehand performance is compared to smart tool-assisted performance and includes assessment of the one-dimensional motion tremor in an active microsurgeon's hand. Surgeon hand tremor-the ability to accurately locate a surgical target and maintain tool tip offset distances-were all improved by smart tool assistance.

Characterization of the fluidic properties of a syringe-based portable vitrectomy device.

PURPOSE: To compare the fluidic properties of the Intrector syringe-based vitrectomy device with other commercially available systems to evaluate its safety in the treatment of vitreoretinal diseases. METHODS: Mean operator comfortable sustainable syringe plunger pull force was determined using a spring-loaded digital scale. Vacuum levels for syringes of different volumes (3, 5, and 10 mL) and pulling forces were quantified with a pressure transducer. Flow rates of water and egg white were measured both with the cutter at 600 cuts per minute and in the off position with the port open. Infusion flow of water was evaluated using a 1-mL syringe. RESULTS: The mean plunger pull force among operators (n = 8) was 0.80 kg (SD, 0.20 kg). Using the 3-mL syringe with 0.91 kg pull force, mean vacuum level was 135.9 mmHg (SD, 4.8 mmHg) and mean cutter-on flow rates of water and egg white were 1.9 mL/min (SD, 0.1 mL/min) and 0.5 mL/min (SD, 0.1 mL/min), respectively. Larger-bore syringes generated lower vacuum levels and liquid flow rates. CONCLUSION: The fluidic parameters of the Intrector vitrectomy device measured in this study suggest that at comfortable sustainable syringe pull forces, vacuum levels and liquid aspiration rates are similar to some other commercially available systems and are likely safe.

Light-emitting diode technology in vitreoretinal surgery.

BACKGROUND: Systems for vitreoretinal illumination during surgery usually consist of an external light source and a light fiber. We introduce a new illumination system for vitreoretinal surgery based on the light-emitting diode technology, with an embedded light source in the handle of the light fiber, making a separate light source unnecessary. METHODS: A prototype of a new illumination system for vitreoretinal surgery (ocuLED; Geuder, Heidelberg, Germany) was tested. This system consists of a handle with a built-in light-emitting diode, supported by an external power source. The OcuLED was analyzed in regards to wavelength, maximum radiant power, and maximum irradiance and was compared with three commercially available vitreoretinal illumination systems. Furthermore, the first intraoperative application and handling were evaluated. RESULTS: The ocuLED system works with a cool white or a neutral white light-emitting diode and is powered externally. The wavelength spectrum shows a maximum at 565 nm and a second peak at 455 nm. Compared with other light sources, the proportion of potentially harmful blue light is low. Maximum radiant power and irradiance are in line with xenon and mercury vapor light sources. The intrasurgical light is bright and offers good visibility. The handle of ocuLED is slightly wider than commonly used light fiber handles, which do not affect its use during surgery. CONCLUSION: Technical progress in light-emitting diode technology allows minimizing the equipment for vitreoretinal illumination. The OcuLED provides bright illumination without an external light source. Wavelength spectrum, maximum radiant power, and irradiance are safe from the risk of phototoxic damage. Intrasurgical handling is identical to conventional light fibers.

Use of the heads-up NGENUITY 3D Visualization System for vitreoretinal surgery: a retrospective evaluation of outcomes in a French tertiary center.

Heads-up three-dimensional (3D) surgical visualization systems allow ophthalmic surgeons to replace surgical microscope eyepieces with high-resolution stereoscopic cameras transmitting an image to a screen. We investigated the effectiveness and safety of the heads-up NGENUITY 3D Visualization System in a retrospective evaluation of 241 consecutive vitreoretinal surgeries performed by the same surgeon using conventional microscopy (CM group) over a 1-year period versus the NGENUITY System (3D group) over a consecutive 1-year period. We included for study vitreoretinal surgeries for treatment of retinal detachment (RD) (98 surgeries), macular hole (MH) (48 surgeries), or epiretinal membrane (ERM) (95 surgeries). A total of 138 and 103 eyes were divided into 3D and CM groups, respectively. We found no differences in 3-month postoperative rates of recurrence of RD (10% versus 18%, p = 0.42), MH closure (82% versus 88%, p = 0.69), or decrease in central macular thickness of ERMs (134 ± 188 µm versus 115 ± 105 µm, p = 0.57) between the 3D and CM groups, respectively. Surgery durations and visual prognosis were also similar between both groups. We consolidate that the NGENUITY System is comparable in terms of visual and anatomical outcomes, giving it perspectives for integration into future robotized intervention.

Intraoperative spectral domain optical coherence tomography for vitreoretinal surgery.

We demonstrate in vivo human retinal imaging using an intraoperative microscope-mounted optical coherence tomography system (MMOCT). Our optomechanical design adapts an Oculus Binocular Indirect Ophthalmo Microscope (BIOM3), suspended from a Leica ophthalmic surgical microscope, with spectral domain optical coherence tomography (SD-OCT) scanning and relay optics. The MMOCT enables wide-field noncontact real-time cross-sectional imaging of retinal structure, allowing for SD-OCT augmented intrasurgical microscopy for intraocular visualization. We experimentally quantify the axial and lateral resolution of the MMOCT and demonstrate fundus imaging at a 20Hz frame rate.