Silicone oil insulation effects on flash electroretinogram and visual evoked potential in patients with retinal detachment / Efectos del aislamiento del aceite de silicona sobre el electrorretinograma flash y el potencial evocado visual en pacientes con desprendimiento de retina

Background: Silicone oil is used as endotamponade following vitreoretinal surgery to maintain the retina reattached when indicated. This study investigates the hypothesis that silicone oil causes insulation effects on the retina by affecting its response to light. Methods: Electrophysiological responses to a flash stimulus were recorded using full-field electroretinography (ERG) and visual evoked potentials (VEP). Recordings were performed in 9 patients who underwent surgery for retinal detachment, before (1–2 days) and after (2–3 weeks) silicone oil removal (SOR) in both the study and the control eye. Flash ERG and VEP recordings were performed according to the ISCEV standard protocol. Results: Statistically significant differences were found in the study eye in the amplitudes of the ERG responses and their corresponding ratios, i.e. the amplitude after SOR over the amplitude before SOR, in all conditions tested. No differences were observed in the control eye. The mean ratio of photopic ERG response was 3.4 ± 2.4 for the study and 1.0 ± 0.3 for the control eye (p<0.001). The mean ratio of ERG flicker response was 3.1 ± 2.4 and 1.0 ± 0.3, respectively (p = 0.003). Scotopic flash ERG ratio was 5.0 ± 4.4 for the study and 1.3 ± 0.6 for the control eye (p = 0.012). No differences were observed for the amplitude and latency of flash VEP response after SOR. Conclusions: Silicone oil causes a reduction in flash ERG responses; no effect was found on flash VEP responses. ERGs in eyes filled with silicone oil should not be considered representative of retinal functionality, in contrast to VEPs, which are not affected by silicone oil presence.(AU)

[Outcomes of bimanual vitreoretinal surgery in the treatment of diabetic retinopathy complications]. / Rezul'taty bimanual'noi vitreoretinal'noi khirurgii v lechenii oslozhnenii diabeticheskoi retinopatii.

The incidence of diabetic retinopathy (DR) requiring vitreorentinal surgery is increasing. The search for new effective and safe methods of treatment, the choice of the optimal time for surgery, and the assessment of long-term treatment outcomes are relevant problems. PURPOSE: This study evaluates the long-term results of vitreorentinal surgery using the bimanual technique in DR with different stages of fibrovascular proliferation. MATERIAL AND METHODS: The study included 135 patients (135 eyes) who were divided into groups depending on the predominant type of proliferation - vascular or fibrous. Patients underwent vitrectomy with membranectomy using the bimanual technique, with peripheral panretinal endolaser coagulation of the retina and tamponade of the vitreous cavity with balanced salt solution. The postoperative observation period lasted up to 12 months. RESULTS: Both groups showed statistically significant improvement in visual function and anatomical changes in central retinal thickness. A statistically significant improvement in best corrected visual acuity (BCVA) was found in patients with initially predominantly vascular proliferation. Correlation analysis showed that initially higher BCVA tends to persist in the postoperative period. A negative correlation was found between the final BCVA and the presence of type 2 diabetes mellitus, fibrous stage of proliferation, high central retinal thickness, and the presence of diabetic macular edema (DME) - both initially and after treatment. The frequency of complications in the groups was comparable, except for postoperative DME, which was more often detected in patients with fibrous proliferation. CONCLUSION: The bimanual technique of vitreorentinal surgery for complications of DR allows achieving high anatomical and functional results. Higher BCVA is noted in patients with the vascular stage of proliferation and initially high BCVA. The obtained data allow us to form a hypothesis about the possibility of earlier surgery in patients with high BCVA, but require further investigation.

Clinical Presentation and Treatment Outcomes of Pupillary Block Glaucoma Following Vitreoretinal Surgery.

PURPOSE: To describe the clinical presentation and treatment outcomes of pupillary block glaucoma (PBG) following vitreoretinal surgery (VR surgery). MATERIAL AND METHODS: Retrospective observational study of 6941 patients, who underwent VR surgery at a tertiary eye care centre in South India between January 2015 and December 2019. Amongst them, clinical data of 61 patients who developed PBG were taken for statistical analysis. RESULTS: Mean (SD) age was 53.90 (13.4) years and the incidence of PBG was .87%. Median (IQR) time of onset of PBG following VR surgery was 3.33 (1.1-6.6) months and majority were pseudophakic (75%). PBG resolved with Nd:YAG laser peripheral iridotomy (LPI) alone in 50 (82%) patients, whereas 11(18%) patients required additional interventions like surgical iridectomy, trabeculectomy or diode laser cyclophotocoagulation (CPC) either as a stand-alone procedure or in combination with silicone oil removal (SOR). Mean (SD) intraocular pressure at the onset of PBG was 41.61 (14.5) mmHg, which reduced drastically following LPI to 24.28 (14.9) mmHg which further dropped significantly at 6 months follow up to 20.34 (13.9) mmHg. CONCLUSIONS: Incidence of secondary PBG after VR surgery was .87%, and we observed diabetes mellitus, combined cataract and VR surgery, use of 1000cs SO endotamponade, intraoperative endolaser and multiple VR surgical interventions as common associations. Majority of the patients with PBG after VR procedures resolved with LPI and medical management. Few individuals (18%) required additional laser or surgical intervention for IOP control.

Democratizing Vitreoretinal Surgery Training With a Portable and Affordable Virtual Reality Simulator in the Metaverse.

Purpose: The purpose of this study was to develop and validate RetinaVR, an affordable, portable, and fully immersive virtual reality (VR) simulator for vitreoretinal surgery training. Methods: We built RetinaVR as a standalone app on the Meta Quest 2 VR headset. It simulates core vitrectomy, peripheral shaving, membrane peeling, and endolaser application. In a validation study (n = 20 novices and experts), we measured: efficiency, safety, and module-specific performance. We first explored unadjusted performance differences through an effect size analysis. Then, a linear mixed-effects model was used to isolate the impact of age, sex, expertise, and experimental run on performance. Results: Experts were significantly safer in membrane peeling but not when controlling for other factors. Experts were significantly better in core vitrectomy, even when controlling for other factors (P = 0.014). Heatmap analysis of endolaser applications showed more consistent retinopexy among experts. Age had no impact on performance, but male subjects were faster in peripheral shaving (P = 0.036) and membrane peeling (P = 0.004). A learning curve was demonstrated with improving efficiency at each experimental run for all modules. Repetition also led to improved safety during membrane peeling (P = 0.003), and better task-specific performance during core vitrectomy (P = 0.038), peripheral shaving (P = 0.011), and endolaser application (P = 0.043). User experience was favorable to excellent in all spheres. Conclusions: RetinaVR demonstrates potential as an affordable, portable training tool for vitreoretinal surgery. Its construct validity is established, showing varying performance in a way that correlates with experimental runs, age, sex, and level of expertise. Translational Relevance: Fully immersive VR technology could revolutionize surgical training, making it more accessible, especially in developing nations.

Comparing Three-Dimensional Digitally Enabled Intraoperative OCT With Conventional Microscope-Integrated OCT in Vitreoretinal Surgery: A Post Hoc Analysis of the DISCOVER Study.

BACKGROUND AND OBJECTIVE: This study compared the surgeon experience between conventional microscope-integrated intraoperative optical coherence tomography (iOCT) and digitally enabled microscope-integrated iOCT in vitreoretinal surgery. PATIENTS AND METHODS: This is a post hoc case-control analysis of the DISCOVER study. Conventional microscope-integrated iOCT (Rescan 700, Zeiss) was compared with digitally enabled iOCT (Artevo 800, Zeiss). Compared variables included surgical field-based visualization (ie, ocular heads-up display in the conventional group; three-dimensional screen-based visualization in the digital iOCT group) and non-surgical field-based visualization (ie, review on the external two-dimensional monitor). RESULTS: A total of 200 patients were included. Surgical field-based visualization of iOCT was significantly higher in the digitally enabled group (P < 0.0001). Required endoillumination level was significantly lower in the digital iOCT group (P < 0.0001). Surgeons reported "significant" back discomfort and headache more frequently when using conventional iOCT (P = 0.003 and P = 0.001, respectively). CONCLUSIONS: Digitally enabled iOCT resulted in greater surgical visualization efficiency, appeared to require a lower illumination level, and may provide advantages for ergonomic-related discomfort. [Ophthalmic Surg Lasers Imaging Retina 2024;55:270-277.].

Clinical significance of signal shadowing during intraoperative optical coherence tomography-assisted vitreoretinal surgery.

This study aimed to analyze the clinical significance of signal shadowing during intraoperative optical coherence tomography (iOCT)-assisted vitreoretinal surgery caused by vitreoretinal instruments, tissue dyes, and vitreous substitutes, and to objectively quantify its impact on iOCT imaging. This is a retrospective observational study of postoperative image analysis from one hundred seventeen (117) patients who underwent iOCT-assisted vitrectomy. The image data were divided into three groups: vitreoretinal instruments, tissue dyes, and vitreous substitutes. The data was then processed using graphic software to measure the grade of picture quality distortion and compared to paired image controls without clinically perceptive interference, then analyzed statistically. The intraocular portion of all studied vitreoretinal instruments caused a high average gray level interference compared to controls ranging from 32 to 68% reduction, obscuring the area of interest significantly. The tips of the instruments produced low-grade shadowing, allowing the underlying tissue to be distinguished. The analyzed dyes demonstrated a wide interference range: ICG (- 75.12%), and triamcinolone (- 26.13%) showed dose-dependent high shadowing, while VITREODYNE™ (49.3%) and brilliant blue G (14.06%) exhibited no perceived distortions whilst increasing average gray levels. All analyzed vitreous substitutes (air, SF6, C3F8, PFCL, and silicone oil) showed an insignificant shadowing effect on iOCT. Certain dyes and vitreous substitutes produce a negligible shadowing effect compared to controls and other dyes, providing an advantage during real-time iOCT imaging. All analyzed vitreoretinal instruments showed a significant interference that should prompt the development of new imaging techniques or the implementation of materials with low-grade interference to overcome a clinically relevant shadowing effect on iOCT, maximizing the technology's visual accuracy and surgical diagnostic aid proficiency.

Outbreak of toxic anterior segment syndrome following vitreoretinal surgery - A retrospective analysis.

BACKGROUND: Toxic anterior segment syndrome (TASS) is an uncommon complication of vitreoretinal surgery and is characterized by severe anterior chamber reaction, hypopyon, and limbus-to-limbus corneal edema. METHODS: Twenty-nine vitreoretinal surgeries were performed, of which 14 developed TASS in the early postoperative period. The operative records were reviewed retrospectively. RESULTS: The median age of patients was 49.07 ± 16.75 years and 14.28% of them were female. Also, 71.42% were operated in the left eye and 42.8% were pseudophakic. Recurrent retinal detachment, secondary scleral-fixating intraocular lens (SFIOL), and silicone oil removal (SOR) were the most common procedures. Severe anterior chamber reaction was seen in 14 patients, circumcorneal congestion in eight, corneal edema in 11 (78.6%), hypopyon in 13 (92.8%), and severe fibrin membrane in two patients. CONCLUSION: We describe the largest series of TASS following uneventful vitreoretinal surgery. Balanced salt solution was the instigating agent in this series. A prompt and thorough investigation is critical in obviating recurrences.

Comparison of three-dimensional heads-up system versus traditional microscopic system in medical education for vitreoretinal surgeries: a prospective study.

BACKGROUND: To compare the value and efficiency of the three-dimensional (3D) heads-up surgical system and traditional microscopic (TM) system in teaching and learning vitreoretinal surgeries. METHODS: Twenty ophthalmologists and scrub nurses were recruited as teachers, and 45 junior ophthalmology residents and trainee doctors, trainee nurses, and medical students were recruited as observers. Each teacher and observer were assigned to both a 3D-assisted and TM-assisted vitreoretinal surgery and then asked to complete satisfaction questionnaires for both surgical systems at the end of each surgery. RESULTS: The 3D heads-up surgical system was rated significantly higher in most of the subscales and overall satisfaction score by both teachers and observers (P < 0.05). However, ratings for instrument adjustment were significantly higher in the TM group compared to the 3D group for junior ophthalmology residents and trainee doctors (6.1 ± 1.7 vs. 8.8 ± 1.1, P < 0.001). CONCLUSIONS: The 3D heads-up surgical system has great didactical value in the medical education of vitreoretinal surgeries, but it is important to consider the specific needs of different learners when choosing between the two systems. TRIAL REGISTRATION: Not applicable.

Color enhancement and achromatization to increase the visibility of indocyanine green-stained internal limiting membrane during digitally assisted vitreoretinal surgery.

PURPOSE: To investigate the impact of using digital assisted vitrectomy (DAV) for color enhancement in color channel and achromatization in color profile on the visibility of indocyanine green (ICG)-stained internal limiting membrane (ILM). STUDY DESIGN: Retrospective observational study. METHODS: Twenty eyes from 20 patients (7 men, 13 women) who underwent 27-gauge pars plana vitrectomy for epiretinal membrane removal were included. The presettings of five different imaging modes of the NGENUITY® 3D visualization system (Alcon laboratories, Inc.), were adjusted, and intraoperative images of ILM removal were captured under each presetting. The color contrast ratios (CCR) between the ICG-stained ILM area and peeled ILM area were compared across presettings objectively. Subjective visibility of ILM in each patient for different presettings was ranked using a Likert scale and evaluated by five examiners. Data on sex, age, preoperative and postoperative best-corrected visual acuity (BCVA), preoperative and postoperative intraocular pressure (IOP), and postoperative complications were analyzed. RESULTS: Compared to other presettings the best CCR was achieved by adjusting the color channel to enhance red and by modifying the color profile to create a monochrome image (P<0.01). The same presetting resulted in a highest subjective visibility (P<0.01). Mean preoperative BCVA and 6-month postoperative BCVA (logMAR) were 0.11±0.18 and 0.05±0.19, respectively (p=0.24). Mean preoperative IOP and 6-month postoperative IOP were 13.8±2.8 mmHg and 13.3±3.4 mmHg, respectively (p=0.51). No apparent intra- and post-operative complications were observed. CONCLUSION: Color enhancement and achromatization using DAV may offer potential advantages to enhance the visibility of ICG-stained ILM.

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.

One-Year Outcomes of the PAUL Glaucoma Implant Compared With the Ahmed Glaucoma Valve for the Treatment of Silicone Oil Glaucoma.

PRCIS: Longer-term studies with a larger sample size are needed to demonstrate the superiority or equivalence of these procedures. OBJECTIVE: To evaluate the outcomes of the PAUL glaucoma implant (PGI) and Ahmed glaucoma valve (AGV) in patients with secondary glaucoma caused due to silicone oil emulsification. PATIENTS AND METHODS: A retrospective examination was conducted using the medical records of 36 patients who developed secondary glaucoma due to silicone oil emulsification after vitreoretinal surgery and then underwent PGI and AGV implantation surgery. The main outcome measures in the PGI and AGV groups were intraocular pressure (IOP) and its change, the number of antiglaucoma medications, and postoperative complications during the 12-month follow-up period. IOP of <6 mm Hg is used to define hypotonia. RESULTS: There was no statistically significant difference among the patients who underwent PGI and AGV surgeries in terms of IOP averages, both preoperatively and postoperatively on day 1, week 1, month 1, month 3, month 6, and month 12 ( P > 0.05). Before PGI and AGV implantation, the mean IOP was 40 ± 13 mm Hg and 39.3 ± 10 mm Hg, and the mean number of medications was 3.8 ± 0.4 and 4 ± 0, respectively. At the end of the 12-month follow-up period, the mean IOP was 13.5 ± 2.2 ( P < 0.001) mm Hg and 14.9 ± 4.2 ( P < 0.001) mm Hg, whereas the mean number of glaucoma medications decreased to 1.7 ± 1.3 ( P < 0.001) and 1.9 ± 1.8 ( P < 0.001) in the PGI and AGV groups, respectively. Surgical success was achieved in 17 of 18 eyes (94%) in the PGI group and 16 of 18 eyes (89%) in the AGV group. CONCLUSIONS: Although the outcomes were similar in both the PGI and AGV groups, complications requiring medical and surgical intervention were less common in the PGI group. Longer-term studies with a larger sample size are needed to demonstrate the superiority or equivalence of these procedures.

OBJECTIVE QUANTIFICATION OF DEPTH-OF-FIELD ADVANTAGE IN 3D SURGICAL VIDEO SYSTEM FOR VITREORETINAL SURGERY: Safety and Efficacy in Macular Diseases.

PURPOSE: The objective of this study was to demonstrate, based on objective clinical indicators, the advantages of depth of field provided by the 3D surgical video system compared with the traditional microscope during vitrectomy for treating epiretinal membranes or macular holes. METHODS: A total of 38 patients were included in this study and randomly assigned to either the 3D surgical video group or the conventional microscope group. Surgical parameters, such as the focal plane adjustment frequency, membrane peeling time, and number of attempts to peel the membrane, were recorded for each patient. In addition, patients were followed up for 3 months postoperatively. RESULTS: No significant differences were observed in age, sex, operated eyes, or follow-up rates between the groups. The 3D group had significantly lower focal plane adjustment frequency in macular hole surgery and epiretinal membrane surgery. No significant differences were observed in peeling maneuvers, time, or total surgical time. Postoperative follow-up data showed no significant differences. CONCLUSION: In conclusion, the 3D surgical video system exhibits potential advantages in depth of field. The 3D surgical video system is a safe and effective technology in vitrectomy for macular diseases.

PERFORMANCE ASSESSMENT OF AN ARTIFICIAL INTELLIGENCE CHATBOT IN CLINICAL VITREORETINAL SCENARIOS.

PURPOSE: To determine how often ChatGPT is able to provide accurate and comprehensive information regarding clinical vitreoretinal scenarios. To assess the types of sources ChatGPT primarily uses and to determine whether they are hallucinated. METHODS: This was a retrospective cross-sectional study. The authors designed 40 open-ended clinical scenarios across four main topics in vitreoretinal disease. Responses were graded on correctness and comprehensiveness by three blinded retina specialists. The primary outcome was the number of clinical scenarios that ChatGPT answered correctly and comprehensively. Secondary outcomes included theoretical harm to patients, the distribution of the type of references used by the chatbot, and the frequency of hallucinated references. RESULTS: In June 2023, ChatGPT answered 83% of clinical scenarios (33/40) correctly but provided a comprehensive answer in only 52.5% of cases (21/40). Subgroup analysis demonstrated an average correct score of 86.7% in neovascular age-related macular degeneration, 100% in diabetic retinopathy, 76.7% in retinal vascular disease, and 70% in the surgical domain. There were six incorrect responses with one case (16.7%) of no harm, three cases (50%) of possible harm, and two cases (33.3%) of definitive harm. CONCLUSION: ChatGPT correctly answered more than 80% of complex open-ended vitreoretinal clinical scenarios, with a reduced capability to provide a comprehensive response.

ASSESSMENT OF SIMULATED SURGICAL DEXTERITY AFTER MODIFIABLE EXTERNAL EXPOSURES AMONG NOVICE VERSUS EXPERIENCED VITREORETINAL SURGEONS.

PURPOSE: To evaluate novice and senior vitreoretinal surgeons after various exposures. Multiple comparisons ranked the importance of these exposures for surgical dexterity based on experience. METHODS: This prospective cohort study included 15 novice and 11 senior vitreoretinal surgeons (<2 and >10 years' practice, respectively). Eyesi-simulator tasks were performed after each exposure. Day 1, placebo, 2.5 mg/kg caffeine, and 5.0 mg/kg caffeine; day 2, placebo, 0.2 mg/kg propranolol, and 0.6 mg/kg propranolol; day 3, baseline simulation, breathalyzer readings of 0.06% to 0.10% and 0.11% to 0.15% blood alcohol concentrations; day 4, baseline simulation, push-up sets with 50% and 85% repetitions maximum; and day 5, 3-hour sleep deprivation. Eyesi-generated score (0-700, worst-best), out-of-tolerance tremor (0-100, best-worst), task completion time (minutes), and intraocular pathway (in millimeters) were measured. RESULTS: Novice surgeons performed worse after caffeine (-29.53, 95% confidence interval [CI]: -57.80 to -1.27, P = 0.041) and alcohol (-51.33, 95% CI: -80.49 to -22.16, P = 0.001) consumption. Alcohol caused longer intraocular instrument movement pathways (212.84 mm, 95% CI: 34.03-391.65 mm, P = 0.02) and greater tremor (7.72, 95% CI: 0.74-14.70, P = 0.003) among novices. Sleep deprivation negatively affected novice performance time (2.57 minutes, 95% CI: 1.09-4.05 minutes, P = 0.001) and tremor (8.62, 95% CI: 0.80-16.45, P = 0.03); however, their speed increased after propranolol (-1.43 minutes, 95% CI: -2.71 to -0.15 minutes, P = 0.029). Senior surgeons' scores deteriorated only following alcohol consumption (-47.36, 95% CI: -80.37 to -14.36, P = 0.005). CONCLUSION: Alcohol compromised all participants despite their expertise level. Experience negated the effects of caffeine, propranolol, exercise, and sleep deprivation on surgical skills.

Randomised controlled trial of adjunctive triamcinolone acetonide in eyes undergoing vitreoretinal surgery following open globe trauma: The ASCOT study.

BACKGROUND/AIMS: To investigate the clinical effectiveness of adjunctive triamcinolone acetonide (TA) given at the time of vitreoretinal surgery following open globe trauma (OGT). METHODS: A phase 3, multicentre, double-masked randomised controlled trial of patients undergoing vitrectomy following OGT comparing adjunctive TA (intravitreal and subtenons) against standard care (2014-2020). The primary outcome was the proportion of patients with at least 10 Early Treatment Diabetic Retinopathy Study (ETDRS) letter improvement in corrected visual acuity (VA) at 6 months. Secondary outcomes included: change in ETDRS, retinal detachment (RD) secondary to PVR, retinal reattachment, macular reattachment, tractional RD, number of operations, hypotony, elevated intraocular pressure and quality of life. RESULTS: 280 patients were randomised over 75 months, of which 259 completed the study. 46.9% (n=61/130) of patients in the treatment group had a 10-letter improvement in VA compared with 43.4% (n=56/129) of the control group (difference 3.5% (95% CI -8.6% to 15.6%), OR=1.03 (95% CI 0.61 to 1.75), p=0.908)). Secondary outcome measures also failed to show any treatment benefit. For two of the secondary outcome measures, stable complete retinal and macular reattachment, outcomes were worse in the treatment group compared with controls, respectively, 51.6% (n=65/126) vs 64.2% (n=79/123), OR=0.59 (95% CI 0.36 to 0.99), and 54.0% (n=68/126) vs 66.7% (n=82/123), OR=0.59 (95% CI 0.35 to 0.98), for TA vs control. CONCLUSION: The use of combined intraocular and sub-Tenons capsule TA is not recommended as an adjunct to vitrectomy surgery following OGT. TRIAL REGISTRATION NUMBER: NCT02873026.

Trocar localisation for robot-assisted vitreoretinal surgery.

PURPOSE: Robot-assisted vitreoretinal surgery provides precise and consistent operations on the back of the eye. To perform this safely, knowledge of the surgical instrument's remote centre of motion (RCM) and the location of the insertion point into the eye (trocar) is required. This enables the robot to align both positions to pivot the instrument about the trocar, thus preventing any damaging lateral forces from being exerted. METHODS: Building on a system developed in previous work, this study presents a trocar localisation method that uses a micro-camera mounted on a vitreoretinal surgical forceps, to track two ArUco markers attached on either side of a trocar. The trocar position is the estimated midpoint between the markers. RESULTS: Experimental evaluation of the trocar localisation was conducted. Results showed an RMSE of 1.82 mm for the localisation of the markers and an RMSE of 1.24 mm for the trocar localisation. CONCLUSIONS: The proposed camera-based trocar localisation presents reasonable consistency and accuracy and shows improved results compared to other current methods. Optimum accuracy for this application would necessitate a 1.4 mm absolute error margin, which corresponds to the trocar's radius. The trocar localisation results are successfully found within this margin, yet the marker localisation would require further refinement to ensure consistency of localisation within the error margin. Further work will refine these position estimates and ensure the error stays consistently within this boundary.