Improved Outcomes with Heavy Silicone Oil in Complex Primary Retinal Detachment: A Large Multicenter Matched Cohort Study.

PURPOSE: To establish whether Densiron 68, a heavier-than-water endotamponade agent, is an effective alternative to conventional light silicone oil in primary rhegmatogenous retinal detachment (RD) surgery for eyes with inferior breaks in the detached retina and severe proliferative vitreoretinopathy (PVR). DESIGN: Cohort study of routinely collected data from the European Society of Retina Specialists and British and Eire Association of Vitreoretinal Surgeons vitreoretinal database between 2015 and 2022. PARTICIPANTS: All consecutive eyes that underwent primary rhegmatogenous RD surgery using Densiron 68 or light silicone oil as an internal tamponade agent. METHODS: To minimize confounding bias, we undertook 2:1 nearest-neighbor matching on inferior breaks, large inferior rhegmatogenous RDs, PVR, and, for visual analyses, baseline visual acuity (VA) between treatment groups. We fit regression models including prognostically relevant covariates, treatment-covariate interactions, and matching weights. We used g-computation with cluster-robust methods to estimate marginal effects. For nonlinear models, we calculated confidence intervals (CIs) using bias-corrected cluster bootstrapping with 9999 replications. MAIN OUTCOME MEASURES: Presence of a fully attached retina and VA at least 2 months after oil removal. RESULTS: Of 1061 eyes enrolled, 426 and 239 were included in our matched samples for anatomic and visual outcome analyses, respectively. The primary success rate was higher in the Densiron 68 group (113 of 142; 80%) compared with the light silicone oil group (180 of 284; 63%), with an adjusted odds ratio of 1.90 (95% CI, 1.63-2.23, P < 0.001). We also observed a significant improvement favoring Densiron 68 of -0.26 logarithm of the minimum angle of resolution (logMAR) in postoperative VA between the 2 groups (95% CI, -0.43 to -0.10, P = 0.002). The anatomic benefit of using Densiron 68 in eyes with inferior retinal breaks and large detachments was more pronounced among eyes with PVR grade C. We found no evidence of visual effect moderation by anatomic outcome or foveal attachment. CONCLUSIONS: Densiron achieved higher anatomic success rates and improved visual outcomes compared with conventional light silicone oil in eyes with inferior retinal pathology and severe PVR. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

The Risk of Sympathetic Ophthalmia Associated with Open-Globe Injury Management Strategies: A Meta-analysis.

TOPIC: Sympathetic ophthalmia (SO) is a sight-threatening granulomatous panuveitis caused by a sensitizing event. Primary enucleation or primary evisceration, versus primary repair, as a risk management strategy after open-globe injury (OGI) remains controversial. CLINICAL RELEVANCE: This systematic review was conducted to report the incidence of SO after primary repair compared with that of after primary enucleation or primary evisceration. This enabled the reporting of an estimated number needed to treat. METHODS: Five journal databases were searched. This review was registered with International Prospective Register of Systematic Reviews (identifier, CRD42021262616). Searches were carried out on June 29, 2021, and were updated on December 10, 2022. Prospective or retrospective studies that reported outcomes (including SO or lack of SO) in a patient population who underwent either primary repair and primary enucleation or primary evisceration were included. A systematic review and meta-analysis were carried out in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Random effects modelling was used to estimate pooled SO rates and absolute risk reduction (ARR). RESULTS: Eight studies reporting SO as an outcome were included in total. The included studies contained 7500 patients and 7635 OGIs. In total, 7620 OGIs met the criteria for inclusion in this analysis; SO developed in 21 patients with OGI. When all included studies were pooled, the estimated SO rate was 0.12% (95% confidence interval [CI], 0.00%-0.25%) after OGI. Of 779 patients who underwent primary enucleation or primary evisceration, no SO cases were reported, resulting in a pooled SO estimate of 0.05% (95% CI, 0.00%-0.21%). For primary repair, the pooled estimate of SO rate was 0.15% (95% CI, 0.00%-0.33%). The ARR using a random effects model was -0.0010 (in favour of eye removal; 95% CI, -0.0031 [in favor of eye removal] to 0.0011 [in favor of primary repair]). Grading of Recommendations, Assessment, Development, and Evaluations analysis highlighted a low certainty of evidence because the included studies were observational, and a risk of bias resulted from missing data. DISCUSSION: Based on the available data, no evidence exists that primary enucleation or primary evisceration reduce the risk of secondary SO. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Face-down positioning or posturing after pars plana vitrectomy for macula-involving rhegmatogenous retinal detachments.

BACKGROUND: A macula-involving rhegmatogenous retinal detachment (RRD) is one of the most common ophthalmic surgical emergencies and causes significant visual morbidity. Pars plana vitrectomy (PPV) with gas tamponade is often performed to repair primary macula-involving RRDs with a high rate of anatomical retinal reattachment. It has been advocated by some ophthalmologists that face-down positioning after PPV and gas tamponade helps reduce postoperative retinal displacement. Retinal displacement can cause metamorphopsia and binocular diplopia. OBJECTIVES: The primary objective of this review is to determine whether face-down positioning reduces the risk of retinal displacement following PPV and gas tamponade for primary macula-involving RRDs. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (which contains the Cochrane Eyes and Vision Trials Register) (2022, Issue 11), MEDLINE (January 1946 to 28 November 2022), Embase.com (January 1947 to 28 November 2022), PubMed (1948 to 28 November 2022), Latin American and Caribbean Health Sciences Literature database (1982 to 28 November 2022), ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform. We did not use any date or language restrictions in the electronic search. We last searched the electronic databases on 28 November 2022. SELECTION CRITERIA: We included randomized controlled trials (RCTs) in which face-down positioning was compared with no positioning or another form of positioning following PPV and gas tamponade for primary macula-involving RRDs. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodology and assessed the certainty of the body of evidence for the prespecified outcomes using the GRADE approach. MAIN RESULTS: We identified three RCTs (369 eyes of 368 participants) that met the eligibility criteria. Two RCTs provided data on postoperative retinal displacement, one reported on postoperative distortion and quality of life outcomes, two on postoperative best-corrected visual acuity (BCVA) in logMAR, and two on postoperative ocular adverse events such as outer retinal folds. Study characteristics and risk of bias All the trials involved predominantly male participants (range: 68% to 72%). Only one trial provided race and ethnicity information, was registered on a trial registry, and reported funding sources. Using the RoB 2 tool, we assessed the risk of bias for proportion of eyes with retinal displacement, mean change in visual acuity, objective distortion scores, quality of life assessments, and ocular adverse events, with most domains judged to be at low risk of bias. Findings Immediate face-down positioning may result in a lower proportion of participants with postoperative retinal displacement compared with support-the-break positioning at six months (risk ratio [RR] 0.73, 95% confidence interval [CI] 0.54 to 0.99; 1 RCT; 239 eyes of 239 participants; very low certainty evidence). One study found no evidence of a difference in BCVA at three months when comparing postoperative face-up with face-down positioning with or without perfluorocarbon liquid (mean difference [MD] -0.03, 95% CI -0.09 to 0.02; I2 = 0; 56 eyes of 56 participants; very low certainty evidence). Immediate face-down positioning appears to have little to no effect on postoperative distortion scores at week 26 (MD 1.80, 95% CI -1.92 to 5.52; 1 RCT; 219 eyes of 219 participants; very low certainty evidence) and postoperative quality of life assessment scores at week 26 (MD -1.80, 95% CI -5.52 to 1.92; 1 RCT; 217 eyes of 217 participants; very low certainty evidence). Adverse events One study that enrolled 262 participants with macula-involving RRDs suggested that immediate face-down positioning after PPV and gas tamponade may reduce the ocular adverse event of postoperative outer retinal folds at six months (RR 0.39, 95% CI 0.17 to 0.90; 1 RCT; 262 eyes of 262 participants; very low certainty evidence) and binocular diplopia (RR 0.20, 95% CI 0.04 to 0.90; 1 RCT; 262 eyes of 262 participants; very low certainty evidence) compared with support-the-break positioning. Immediate face-down positioning may increase the ocular adverse event of elevated intraocular pressure compared with support-the-break positioning (RR 1.74, 95% CI 1.11 to 2.73; 1 RCT; 262 eyes of 262 participants; very low certainty evidence). Another study found no evidence of a difference in postoperative outer retinal folds when comparing face-down versus face-up positioning at one and three months (RR 1.00, 95% CI 0.50 to 2.02; RR 1.00, 95% CI 0.28 to 3.61; 1 RCT; 56 eyes of 56 participants; very low certainty evidence). No studies reported non-ocular adverse events. AUTHORS' CONCLUSIONS: Very low certainty evidence suggests that immediate face-down positioning after PPV and gas tamponade may result in a reduction in postoperative retinal displacement, outer retinal folds, and binocular diplopia, but may increase the chance of postoperative raised intraocular pressure compared with support-the-break positioning at six months. We identified two ongoing trials that compare face-down positioning with face-up positioning following PPV and gas tamponade in participants with primary macula-involving RRDs, whose results may provide relevant evidence for our stated objectives. Future trials should be rigorously designed, and investigators should analyze outcome data appropriately and report adequate information to provide evidence of high certainty. Quality of life and patient preferences should be examined in addition to clinical and adverse event outcomes.

A Scoping Review of the Epidemiology, Management, and Outcomes of Golf-Related Fractures.

ABSTRACT: Golf is a popular sport; however, there is a paucity of data in relation to golf-associated fractures, and the rate and timing of returning to golf. The aim of this review is to describe golf-associated fractures, including epidemiology, management, and timing of returning to golf following treatment. A literature search was performed using MEDLINE/PubMed, Embase, and Web of Science. Data were extracted and summarized in a narrative synthesis. A total of 436 articles were identified with an initial search of which 58 met the inclusion criteria. Twelve anatomical sites of golf swing-related fractures were identified, of which 10 sites were specific for stress fractures. The most common sites of golf swing-related stress fractures were the ribs followed by the hook of hamate. There was a common theme of delay to diagnosis, being initially assigned to a soft tissue injury. Most golfers with swing-related stress fractures were able to return to golf with the exception of osteoporotic associated vertebral stress fractures. Timing of returning to golf was between 4 and 12 months for most of the golfers with stress fractures following conservative management. Operative intervention was an option of hook of hamate nonunion, following a stress fracture, and tibial shaft stress fractures. Golf equipment-related fractures were not rare and were associated with major trauma and in some cases associated with significant persistent morbidity. Golf-related stress fractures commonly involve the ribs and hook of hamate; knowledge of this may aid in early diagnosis and appropriate treatment when symptomatic golfers are encountered. Although golf is a noncontact sport, fractures associated with golf equipment can be life changing, and safety training guidelines should be established.

Artificial intelligence using deep learning to predict the anatomical outcome of rhegmatogenous retinal detachment surgery: a pilot study.

PURPOSE: To develop and evaluate an automated deep learning model to predict the anatomical outcome of rhegmatogenous retinal detachment (RRD) surgery. METHODS: Six thousand six hundred and sixty-one digital images of RRD treated by vitrectomy and internal tamponade were collected from the British and Eire Association of Vitreoretinal Surgeons database. Each image was classified as a primary surgical success or a primary surgical failure. The synthetic minority over-sampling technique was used to address class imbalance. We adopted the state-of-the-art deep convolutional neural network architecture Inception v3 to train, validate, and test deep learning models to predict the anatomical outcome of RRD surgery. The area under the curve (AUC), sensitivity, and specificity for predicting the outcome of RRD surgery was calculated for the best predictive deep learning model. RESULTS: The deep learning model was able to predict the anatomical outcome of RRD surgery with an AUC of 0.94, with a corresponding sensitivity of 73.3% and a specificity of 96%. CONCLUSION: A deep learning model is capable of accurately predicting the anatomical outcome of RRD surgery. This fully automated model has potential application in surgical care of patients with RRD.

A Novel Postoperative Drop Regimen Reduces Risk of Ocular Hypertension Following Pars Plana Vitrectomy.

INTRODUCTION: Postoperative steroid/antibiotic drop regimens are known to effectively suppress inflammation and infection following pars plana vitrectomy (PPV), but the steroid frequently induces ocular hypertension (OHT). The aim of this contemporaneous cohort-control study was to assess safety and efficacy of a novel post-PPV drop regimen conceived to address this problem. METHODS: Electronic case notes of consecutive eyes undergoing PPV between December 2020 and April 2021 at St. Thomas' Hospital, London, UK, were reviewed retrospectively. Postoperative drops in the intervention cohort consisted of 1-week g. dexamethasone 0.1%/antibiotic QDS and 1-month g. ketorolac TDS. Standard care controls received 1-month g. dexamethasone 0.1%/antibiotic QDS. RESULTS: Fifty-eight patients were in the intervention cohort, and 151 received standard care. The primary outcome measure was IOP ≥30 mm Hg 2 weeks postoperatively. This occurred in none of the intervention group but in 14% of controls (p = 0.01). Secondary outcomes of rates of anterior uveitis and cystoid macular edema did not differ significantly between the groups, but those in the intervention cohort had fewer hospital visits (p = 0.0004). CONCLUSION: A post-PPV drop regimen of 1-week dexamethasone 0.1%/antibiotic and 1-month ketorolac may be as effective as an anti-inflammatory but safer in terms of OHT incidence than standard care 1-month dexamethasone 0.1%.

Continuous walking and time- and intensity-matched interval walking: Cardiometabolic demand and post-exercise enjoyment in insufficiently active, healthy adults.

We compared cardiometabolic demand and post-exercise enjoyment between continuous walking (CW) and time- and intensity-matched interval walking (IW) in insufficiently active adults. Sixteen individuals (13 females and three males, age 25.3 ± 11.1 years) completed one CW and one IW session lasting 30 min in a randomised-counterbalanced design. For CW, participants walked at a mean intensity of 65-70% predicted maximum heart rate (HRmax). For IW, participants alternated between 3 min at 80% HRmax and 2 min at 50% HRmax. Expired gas was measured throughout each protocol. Participants rated post-exercise enjoyment following each protocol. Mean HR and V˙O2 showed small positive differences in IW vs. CW (2, 95%CL 0, 4 beat.min-1; d = 0.23, 95%CL 0.06, 0.41 and 1.4, 95%CL 1.2 ml.kg-1.min-1, d = 0.36, 95%CL 0.05, 0.65, respectively). There was a medium positive difference in overall kcal expenditure in IW vs. CW (25, 95%CL 7 kcal, d = 0.58, 95%CL 0.33, 0.82). Post-exercise enjoyment was moderately greater following IW vs. CW (9.1, 95%CL 1.4, 16.8 AU, d = 0.62, 95%CL 0.06, 0.90), with 75% of participants reporting IW as more enjoyable. Interval walking elicits meaningfully greater energy expenditure and is more enjoyable than CW in insufficiently active, healthy adults.

Fatigue in adults with primary antiphospholipid syndrome: findings from a mixed-methods study.

OBJECTIVE: This study aimed to explore the experience and impact of fatigue in adults with primary antiphospholipid syndrome (pAPS). METHODS: This sequential, explanatory mixed-methods study enrolled adults with a six-month or more history of pAPS. Consenting participants completed the Functional Assessment of Chronic Illness Therapy-Fatigue subscale (FS), Multi-Dimensional Perceived Social Support Scale, Patient Health Questionnaire (PHQ9), Pittsburgh Sleep Quality Index (PSQI), International Physical Activity Questionnaire (IPAQMETS). Relationships between FS and other variables were explored with multiple linear regression. Interviews were conducted with a subgroup of participants, and the data were analysed thematically. RESULTS: A total of 103 participants were recruited (Mage = 50.3 years; standard deviation = 10.1 years; 18 males). Of these, 62% reported severe fatigue. Greater fatigue was associated with lower mood, physical inactivity, poorer sleep quality and lower perceived social support. The best-fit model explained 56% of the variance in FS (adjusted R2 = 0.560, F(3, 74) = 33.65, p > 0.001) and included PHQ9 and IPAQMETS as significant predictors, and PSQI as a non-significant predictor. Twenty participants completed interviews. Three key themes were identified: characteristics of fatigue, impact on life and coping strategies. CONCLUSION: Fatigue was a common symptom of pAPS and challenging to manage. Other factors, particularly mood and physical activity, influenced fatigue. Evidence-based self-management interventions are needed.

Rate of Postoperative Autofluorescent Macular Shift with Expanding Gas Bubble Tamponade and No Prone Posture Ambulatory Care in Patients with Macula-Involved Retinal Detachment.

PURPOSE: Chronically distorted vision is an important adverse outcome in patients with otherwise successfully treated macula-involved retinal detachment (RD). Symptomatic distortion is associated with macular vessel shift on fundus autofluorescence (FAF) imaging. Immediate prone posture has to date been the only mechanism adopted to reduce postoperative FAF shift. The aim of this study was to establish the rates of primary anatomical success and (FAF) macular shift in 67 eyes with macula-involved RD and superior breaks treated with vitrectomy, retinopexy, 0.7-1 mL 100% gas tamponade, and no prone posture. METHODS: Single-center, retrospective series. RESULTS: Rates of primary anatomical success and fundus autofluorescent imaging macular shift were 89 and 26%, respectively. CONCLUSION: Vitrectomy with a 0.7-1 mL expanding gas bubble tamponade and no prone posture were associated with an acceptable rate of primary anatomical success. We found the lowest yet reported rate of FAF shift in patients with macula-involved RD. If confirmed, this simple technique modification could improve the visual outcome of RD surgery whilst facilitating postoperative ambulatory care.

THE ROLE OF INTRAOCULAR GAS TAMPONADE IN RHEGMATOGENOUS RETINAL DETACHMENT: A Synthesis of the Literature.

PURPOSE: To review the literature regarding intraocular gas tamponade after vitrectomy for rhegmatogenous retinal detachment. METHODS: The history and evolution of the use of gas is described. The theories explaining gas tamponade are discussed, and efficacy and safety studies in human and animal models are covered. RESULTS: A total of 61 articles relating to gas tamponade were cited in this review. CONCLUSION: Gas tamponade is a frequently used procedure in vitreoretinal surgery. An understanding of its mechanism of action is crucial for its safe use when determining which gas is to be used and at what concentration.

THEORETICAL GAS CONCENTRATIONS ACHIEVING 100% FILL OF THE VITREOUS CAVITY IN THE POSTOPERATIVE PERIOD: A Gas Eye Model Study.

PURPOSE: To determine the concentrations of different gas tamponades in air to achieve 100% fill of the vitreous cavity postoperatively and to examine the influence of eye volume on these concentrations. METHODS: A mathematical model of the mass transfer dynamics of tamponade and blood gases (O2, N2, and CO2) when injected into the eye was used. Mass transfer surface areas were calculated from published anatomical data. The model has been calibrated from published volumetric decay and composition results for three gases sulphahexafluoride (SF6), hexafluoroethane (C2F6), or perfluoropropane (C3F8). The concentrations of these gases (in air) required to achieve 100% fill of the vitreous cavity postoperatively without an intraocular pressure rise were determined. The concentrations were calculated for three volumes of the vitreous cavity to test whether ocular size influenced the results. RESULTS: A table of gas concentrations was produced. In a simulation of pars plana vitrectomy operations in which an 80% to 85% fill of the vitreous cavity with gas was achieved at surgery, the concentrations of the 3 gases in air to achieve 100% fill postoperatively were 10% to 13% for C3F8, 12% to 15% for C2F6, and 19% to 25% for SF6. These were similar to the so-called "nonexpansive" concentrations used in the clinical setting. The calculations were repeated for three different sizes of eye. Aiming for an 80% fill at surgery and 100% postoperatively, an eye with a 4-mL vitreous cavity required 24% SF6, 15% C2F6, or 13% C3F8; 7.2 mL required 25% SF6, 15% C2F6, or 13% C3F8; and 10 mL required 25% SF6, 16% C2F6, or 13% C3F8. When using 100% gas (e.g., used in pneumatic retinopexy), to achieve 100% fill postoperatively, the minimum vitreous cavity fill at surgery was 43% for SF6, 29% for C2F6, and 25% for C3F8 and was only minimally changed by variation in the size of the eye. CONCLUSION: A table has been produced, which could be used for surgical innovation in gas usage in the vitreous cavity. It provides concentrations for different percentage fills, which will achieve a moment postoperatively with a full fill of the cavity without a pressure rise. Variation in axial length and size of the eye does not seem to alter the values in the table significantly. Those using pneumatic retinopexy need to increase the volume of gas injected with increased size of the eye to match the percentage fill of the vitreous cavity recommended for a given tamponade agent.

INTRAOPERATIVE AND POSTOPERATIVE COMPLICATIONS IN PHACOVITRECTOMY FOR EPIRETINAL MEMBRANE AND MACULAR HOLE: A Clinical Audit of 1,000 Consecutive Eyes.

PURPOSE: The aim of this study was to report the intraoperative and postoperative complications of phacovitrectomy for epiretinal membrane (ERM) and macular hole (MH). METHODS: This was a retrospective audit of 1,052 phacovitrectomy operations (410 for ERM and 642 for MH) by the same surgical team between 1998 and 2017. Outcome measures included rates of intraoperative anterior segment and posterior segment complications such as posterior capsule rupture and retinal breaks. A subgroup analysis of 189 procedures in which postoperative complications were rigorously recorded was also undertaken. RESULTS: The rate of posterior capsule rupture was 2.2%, with no difference between ERM and MH (1.7 vs. 2.5%; P = 0.40). Iatrogenic retinal tears were more common in MH than in ERM surgery (15.6 vs. 6.8%; P < 0.001). The chance of one or more anterior segment or posterior segment intraoperative complications occurring (excluding iatrogenic retinal breaks) was not associated with: indication for surgery, grade of surgeon, gauge of surgery, surgical machine, diabetic status, patient sex, or patient age. Subgroup analysis showed postoperative events as follows: posterior capsular opacification 10.6% (20/189), posterior synechiae 4.2% (8/189), uveitis 2.1% (4/189), angle closure glaucoma 1.6% (3/189), and rhegmatogenous retinal detachment 1.1% (2/189). CONCLUSION: Phacovitrectomy seems to be safe in phakic patients with ERM or MH, performed either by fellows or consultants. It avoids the requirement for repeat surgery and is more cost and resource efficient.

ROYAL COLLEGE OF OPHTHALMOLOGISTS' NATIONAL DATABASE STUDY OF VITREORETINAL SURGERY: Report 7, Intersurgeon Variations in Primary Rhegmatogenous Retinal Detachment Failure.

BACKGROUND/PURPOSE: To audit variations in primary rhegmatogenous retinal detachment (RD) anatomical failure rates between surgeons, grades of surgeons, and techniques of RD surgery. METHODS: Clinical data of a total of 5,857 eyes undergoing primary RD surgery, from 2000 to 2013 were retrospectively extracted from 15 centers using the same commercially available electronic medical record system, from three vitreoretinal units using an in-house electronic medical record, and from the British and Eire Association of Vitreoretinal Surgeons online registry. RESULTS: The 5,857 primary RD operations were performed by 117 surgeons: 3,349 (57.2%) by consultants, 520 (8.9%) by independent nonconsultants, and 1,988 (33.9%) by trainees. Surgery comprised pars plana vitrectomy for 4,666 (79.7%) operations, scleral buckle for 815 (13.9%), and pars plana vitrectomy + scleral buckle for 376 (6.4%). The RD reoperation rate at 6 months after primary surgery was 13.9% (725/5,202) and did not differ significantly between consultants and trainees (P = 0.382). For surgeons contributing ≥50 cases, the mean (range) reoperation rates were 13.1% (6.7%-26.8%), 15.1% (11.3%-18.2%), and 15.3% (9.4%-22.1%) for consultants, independent nonconsultants, and trainee surgeons, respectively. The scleral buckle failure rate was not significantly different from pars plana vitrectomy (P = 0.095). Data were not adjusted for case-mix complexity. CONCLUSION: The grades of surgeons and the technique of surgery were not associated with a significant difference in primary unadjusted RD failure rates.

Accuracy and feasibility of a dedicated image guidance solution for endoscopic lateral skull base surgery.

OBJECTIVE: We aimed to design, build and validate a surgical navigation system which fulfills the accuracy requirements for surgical procedures on the ear and the lateral skull base, and which integrates with the endoscopic workflow and operating room setup. MATERIALS AND METHODS: The navigation system consists of portable tablet computer (iPad Pro, Apple Computer, USA) and an optical tracking system (Cambar B1, Axios3D, Germany), both connected via a wireless Bluetooth link and attached directly to the OR table. Active optical tracking references are rigidly fixed to both the patient and surgical tools. Software to support image import, registration and 2D/3D visualization has been developed. Two models were used for targeting accuracy assessment: a technical phantom model and an ex vivo temporal bone model. Additionally, workflow integration and usability of the navigation system during endoscopic lateral skull base procedures was investigated in ex vivo experiments on 12 sides of cadaver head specimens. RESULTS: The accuracy experiments revealed a target registration error in the technical phantom model of 0.20 ± 0.10 mm (n = 36) and during the ex vivo assessment of 0.28 ± 0.10 mm (n = 21). Navigation was successfully carried out in n = 36 procedures (infracochlear, suprageniculate and transpromontorial approach), with navigated instruments usable without interference with the endoscope. The system aided in the successful and accurate identification of vital anatomical structures. CONCLUSIONS: Useful surgical navigation is, to a large extent, a result of sufficiently accurate tracking technology. We have demonstrated sufficient accuracy and a potentially suitable integration for surgical application within endoscopic lateral skull base procedures.

A concept for electromagnetic navigated targeting of liver tumors using an angiographic approach.

BACKGROUND: The benefits of using navigation technology for percutaneous local ablation of selected hepatocellular carcinoma (HCC) have been shown. Due to additional efforts in the procedural workflow, barriers to introducing navigation systems on a broad clinical level remain high. In this work, initial steps toward a novel concept for simple and precise targeting of HCC are evaluated. MATERIAL AND METHODS: The proposed technique is based on an angiographic approach using an intrahepatic electromagnetic (EM) reference, for consecutive percutaneous navigated positioning of ablation probes. We evaluated the environmental influence of the angiography suite on EM tracking accuracy, the measurement of a 3 D offset from two 2 D fluoroscopy images, and the accuracy and efficiency of the proposed approach in a porcine liver model. RESULTS: The C-arm had a major influence on EM tracking accuracy, with an error up to 3.8 mm. The methodology applied for measurement of a 3 D offset from 2 D fluoroscopy images was confirmed to be feasible with a mean error of 0.76 mm. In the porcine liver model experiment, the overall target positioning error (TPE) was 2.0 mm and time for navigated targeting was 17.9 seconds, when using a tracked ablation probe. CONCLUSIONS: The initial methodology of the proposed technique was confirmed to be feasible, introducing a novel concept for simple and precise navigated targeting of HCC.

Duration of intraocular gases following vitreoretinal surgery.

BACKGROUND: Intraocular gas tamponades are an important tool in modern vitreoretinal surgery. However, there is considerable variation in their use and perceptions amongst clinicians regarding these agents. METHODS: An electronic survey of vitreoretinal surgeons in the UK was undertaken to establish the patterns of use and surgeons' estimates of the longevity and expansion timing of gas tamponades. In addition, data were prospectively collected on the longevity of gas tamponades in 114 patients from our unit. An analysis was performed to identify patient or surgery factors affecting gas longevity RESULTS: A wide variation in the patterns of use and estimates of longevity and expansion timing of intraocular tamponades was found in the survey of vitreoretinal surgeons. Data from our unit give informed estimates on the longevity of three commonly used tamponades. For 30 % sulphur hexafluoride (SF6), mean 18.0 days, standard deviation (SD) 2.6 days. For 20 % hexafluoroethane (C2F6), mean 34.5 days, SD 3.3 days. For 15 % perfluoropropane (C3F8), mean 67.7 days SD 5.5 days. In the C2F6 group there was correlation between longer duration of the gas bubble and longer axial length (r = 0.438, p = 0.02) and longer gas duration with male sex (p = 0.002). CONCLUSIONS: We present informed gas tamponade longevity figures in clinical practice and report statistically significant associations between longer gas longevity and increasing axial length and male sex.

INCIDENCE OF LENS TOUCH DURING PARS PLANA VITRECTOMY AND OUTCOMES FROM SUBSEQUENT CATARACT SURGERY.

PURPOSE: To determine the incidence of lens touch during pars plana vitrectomy (PPV) and evaluate cataract surgery complications after lens touch. METHODS: One thousand three hundred and ninety nine phakic patients who underwent PPV during the period from 2001 to 2013 were included in the study. Data of the PPV and lens touch (excluding lens bite) complications were reviewed from an electronic database (VITREOR). Subsequent cataract surgery data and intraoperative complications were reviewed. A control group consisted of 149 cases of phakic patients who underwent PPV with no lens touch then subsequent cataract surgery. All surgeries were performed by senior surgeons, and no cataract was present before the PPV. RESULTS: The incidence of lens touch was 3.7% (52 of 1,399 phakic patients). The Demographics and presenting complaints of the patients were not significantly associated with lens touch, but retinal detachment with proliferative vitreoretinopathy, the use of silicone oil and use of relaxing retinectomy were associated with more lens touch. Cataract developed in 49 patients of whom 45 underwent cataract surgery. Nuclear sclerosis developed in 22 patients, 16 had posterior subcapsular, 8 had mixed lens opacities, and 3 had white cataract. The median duration between PPV and cataract surgery was 4 months in the lens touch group, which was significantly shorter than the median of 8 months in the control group (P = 0.001). During the subsequent cataract surgery in the lens touch group, 5 patients (11%) had a posterior capsule rupture, whereas the control group had only 2 cases of posterior capsule rupture 1.4% (P = 0.008). Final visual acuity was 0.3 LogMar or better in 22 patients (44%). CONCLUSION: Lens touch is a frequent complication of PPV in a phakic eye. It is more common in patients having surgery for proliferative vitreoretinopathy. Care should be taken when performing subsequent cataract surgery on an eye with lens touch as it carries a significantly increased chance of posterior capsule rupture.

MEASUREMENT OF RETINAL DISPLACEMENT AND METAMORPHOPSIA AFTER EPIRETINAL MEMBRANE OR MACULAR HOLE SURGERY.

PURPOSE: To quantify retinal displacement and metamorphopsia after surgery for epiretinal membrane (ERM) or full-thickness macular hole (FTMH). METHODS: Fundus autofluorescence imaging was analyzed for evidence of retinal displacement. Displacement was quantified using a novel standardized approach with measures of vertical interarcade distance, fovea to disk margin, and perimacular area. The vertical disk diameter and normal fellow eyes served as controls. Metamorphopsia was quantified using the Morphision test. RESULTS: Thirty-three eyes of 33 consecutive patients underwent vitrectomy (21 for ERM; 12 for FTMH). After surgery for ERM, the macula expanded (perimacular area: +10.14%, P < 0.0001; intraarcade distance: +6.10%, P < 0.0001; fovea to disk margin: +4.80%, P = 0.0042). Conversely, after surgery for FTMH the macula parameters showed evidence of constriction (interarcade distance: -2.11%, P = 0.0047; perimacular area: -2.95%, P = 0.0197; fovea to disk margin: -4.69%, P = 0.0010). The degree of change in intraarcade distance and perimacular area was greater for the ERM compared with the FTMH (P < 0.0001). The vertical disk diameter was not altered by surgery for either the ERM or the FTMH. The average change in any measurements between visits in control eyes was just 0.61%, representing high test-retest reliability. Preoperative morphision distortion scores were worse with FTMH (57.3%) than ERM (38%, P = 0.0636) and improved overall after surgery (43.6-21.3%, P = 0.0019). CONCLUSION: Serial fundus autofluorescence imaging, with the measurement parameters used here, is a reliable means of monitoring retinal blood vessel movement over time. Significant retinal displacement occurs after vitrectomy for FTMH and ERM with the retina expanding after ERM removal and contracting after FTMH closure, with associated improvements in measured metamorphopsia.

EXTENT AND LOCATION OF INTRARETINAL AND SUBRETINAL FLUID AS PROGNOSTIC FACTORS FOR THE OUTCOME OF PATIENTS WITH OPTIC DISK PIT MACULOPATHY.

PURPOSE: To determine if baseline fundoscopic and optical coherence tomography (OCT) features influence the clinical course of optic disk pit maculopathy. METHODS: A multicenter retrospective case note review was undertaken, using standardized OCT and clinical data collection. Visual success was defined as at least a two-line visual acuity improvement, anatomical success as full resolution of OCT foveal fluid with restoration of the normal foveal contour, and partial anatomical success as incomplete resolution of the OCT foveal fluid. Outcomes were compared with a synthesis of the literature, using similar eligibility criteria. RESULTS: Of 36 patients (36 eyes), 2 spontaneously improved and 34 underwent surgery. Visual success was achieved in 64% of surgical cases, anatomical success in 36%, and partial anatomical success in 47%. Cases with multilayer intraretinal and subretinal fluid were less likely to have visual success (P = 0.003). Cases where the fluid did not extend to the macular arcade vessels also had better visual and anatomical outcomes (P = 0.004 and 0.005, respectively). CONCLUSION: Fundoscopic and OCT features can help predict surgical outcome in optic disk pit maculopathy.