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.

Macular hole Delphi consensus statement (MHOST)

PURPOSE

To derive a Delphi method-based consensus for the surgical management of Full Thickness Macular Hole (FTMH) and Lamellar Macular Hole (LMH).

METHODS

37 expert VR surgeons from 21 mainly European countries participated in Delphi method-based questionnaire for diagnosis and treatment of FTMHs and LMHs.

RESULTS

A total of 36 items were rated in round 1 by 37 participants, of which 10 items achieved consensus: intraoperative verification of PVD; clinical superiority of OCT-based FTMH classification; practical ineffectiveness of ocriplasmin; circular 360° ILM peeling for small macular holes; use of regular surgical technique for the size of the hole in concomitant retinal detachment; performing complete vitrectomy; SF6 gas as preferred tamponade; cataract surgery if crystalline lens is mildly/moderately opaque; removal of both ILM and LHEP in LMH surgery. In round 2, 18 items with moderate consensus (45-70% agreement) in round 1 were rated by 35 participants. Final consensus was reached in 35% of questions related to both diagnosis and surgical procedures.

CONCLUSIONS

This Delphi study provides valuable information about the consensus/disagreement on different scenarios encountered during FTMH and LMH management as a guide tosurgical decision-making. High rate of disagreement and/or variable approaches still exist for treating such relatively common conditions.

[Vitreoretinal surgery in age-related macular degeneration]

The structure of the vitreous body, its interaction with the retinal surface and tractive alterations of the vitreoretinal interface may play a role in the pathogenesis and the development of age-related macular degeneration (AMD). From clinical trials it can be concluded that posterior vitreous detachment (PVD) or vitreous removal may protect against the development of neovascular AMD. Vitreomacular adhesions may promote neovascular AMD and may have an impact on the efficacy and frequency of intravitreal vascular endothelial growth factor (VEGF) inhibition. Therefore, vitreomacular surgery may be considered as a treatment option in selected cases. Peeling of epimacular membranes and the internal limiting membrane (ILM) may contribute to stabilizing visual acuity and reducing the treatment burden of current intravitreal pharmacotherapy. At present, surgical interventions in AMD are mainly performed in cases of submacular hemorrhage involving the fovea. The treatment is not standardized and consists of liquefaction of the blood using recombinant tissue plasminogen activator (rTPA) and its pneumatic displacement, potentially combined with VEGF inhibition. Other submacular surgical strategies, such as choroidal neovascularization (CNV) extraction, macular translocation or transplantation of retinal pigment epithelium (RPE) are currently limited to selected cases as a salvage treatment; however, the development of these submacular surgical interventions has formed the basis for new approaches in the treatment of dry and neovascular AMD including submacular or intravitreal gene and stem cell therapy.

[Role of vitreous in the pathogenesis of neovascular age-related macular degeneration]

Age-related changes in vitreous molecular and anatomic morphology begin early in life and involve two major processes: vitreous liquefaction and weakening of vitreo-retinal adhesion. An imbalance in these two processes results in anomalous posterior vitreous detachment (PVD), which comprises, among other conditions, vitreo-macular adhesion (VMA) and traction (VMT). VMA is more common in patients with neovascular age-related macular degeneration (nAMD) than age-matched control patients, with the site of posterior vitreous adherence to the inner retina correlating with location of neovascular complexes. The pernicious effects of an attached posterior vitreous on age-related macular degeneration (AMD) progression involve mechanical forces, enhanced fluid influx and inflammation in and between the retinal layers, hypoxia leading to an accumulation of vascular endothelial growth factor (VEGF) and other stimulatory cytokines, and probably an infiltration of hyalocytes. It has been shown that vitrectomy not only mitigates progression to end-stage AMD, but existing choroidal neovascularization regresses after surgery. Thus, surgical PVD induction during vitrectomy or by pharmacologic vitreolysis may be considered in non-responders to anti-VEGF treatment with concomitant VMA.

[Vitreous body in the treatment of exudative age-related macular degeneration : The medium is the message]

BACKGROUND

Intravitreal anti-vascular endothelial growth factor (VEGF) is the standard treatment for exudative age-related macular degeneration (AMD). The constitution of the vitreomacular interface varies greatly in cases of attached (with or without traction) or detached vitreous body, which can impact the effectiveness of the anti-VEGF treatment.

OBJECTIVE

Based on the current literature this article displays the current state of the science on whether the constitution of the vitreous body has an effect on the anti-VEGF treatment.

MATERIAL AND METHODS

The published data extracted from current trials and post hoc analyses concerning this topic are presented and put into the clinical context.

RESULTS

The presence of a vitreomacular adhesion reduces the efficacy of anti-VEGF treatment of exudative AMD. Posterior vitreous body detachment represents a positive prognostic factor concerning the efficacy of anti-VEGF treatment but not necessarily the prognosis for visual acuity.

CONCLUSION

Patients with attached vitreous body need a more intensive treatment monitoring compared to patients with detached vitreous body. Therefore, in eyes with initial posterior vitreous body detachment receiving a treat and extend regimen, the interval between anti-VEGF injections can be extended to 4 instead of 2 weeks without endangering the success of treatment.

Retinal detachment during COVID-19 era: a review of challenges and solutions

Background

Since the beginning of the Coronavirus disease 2019 (COVID-19) pandemic, there have been obstacles in the proper diagnosis and management of many diseases. We evaluated the changes in retinal detachment (RD) presentation and surgery during the COVID-19 pandemic and propose solutions to minimize the detrimental effects of lockdown on RD diagnosis.

Materials and methods

PubMed, Embase, Scopus, Web of Science, and Google Scholar were searched for relevant articles with the keywords “Retinal detachment” AND “Coronavirus OR COVID-19 OR SARS OR MERS.”

Results

The COVID-19 lockdown was associated a 53–66% reduction in RD presentation. The decrease in the rate of macula-on RD, the increase in the mean duration of symptoms, and the rise in the number of patients with proliferative vitreoretinopathy were all suggestive of a delayed presentation of RD. Moreover, a drop of 56–62% in RD repair surgeries was observed. However, the most frequently performed ophthalmic surgery changed from cataract surgery in April 2019 to RD repair in April 2020. Using phacovitrectomy instead of vitrectomy alone can reduce the number of operations in ophthalmology centers, decrease the use of personal protective equipment by 50%, and cut costs per patient by 17–20%. Also, developing a well-organized telemedicine system can decrease unnecessary visits and delayed presentations.

Conclusion

Delay in RD presentation and surgery is associated with a poorer prognosis. Optimizing the guidelines of RD management and developing a well-organized telemedicine system can minimize the impact of lockdown on RD management.

Novel Needle for Intravitreal Drug Delivery: Comparative Study of Needle Tip Aspirates, Injection Stream and Penetration Forces

Purpose

To study the efficacy of a novel needle for intravitreal injection (IVI) in comparison to the conventional needle under experimental conditions.

Methods

The newly designed 30-gauge (G) needle (NDN) (EP 18158 542.3, patent pending) with occluded outer orifice and a side port for drug delivery was compared to the conventional standard hypodermic 30 G needle for IVI (SHN). An animal study to obtain needle tip aspirates was performed on 10 albino rat eyes. During IVIs, cellular content, which was cut by the needle tip, was aspirated. Cellular material was studied in regard to cell types and their quantity. The injection stream was studied using trypan blue dye in vitro and pig cadaver eyes. The penetration force was tested on polyurethane Testing Foil Strips PU 04 (Melab, Leonberg, Germany) by applying a velocity of 100 mm/min. The results were analyzed using descriptive statistics, correlation matrices and t-test methods with p<0.05 as statistically significant.

Results

Cytological analysis of the needle aspirates showed the presence of cellular content in each case. The amount of conjunctival, ciliary body epithelial cells and granulated basophilic protein sediments (sign of cellular damage) in the case of the NDN tips was significantly lower compared to the SHN. The average penetration force of the NDN was 0.791 N, and in the case of the SHN was 0.566 N. The injection stream study revealed a difference in the initial injection phase between the two needle types, although the diffuse filling of the vitreous area which surrounded the needle tip appeared to be similar.

Discussion

The NDN demonstrated superior performance with regard to a significantly reduced number of cells being captured by the needle tip. Delivery of the injected fluid into the vitreous cavity was comparable. In order to investigate superior properties of the NDN needle design, further studies with improved prototypes would be necessary.

Biometric technology in "no-gate border crossing solutions" under consideration of privacy, ethical, regulatory and social acceptance

Biometric technologies have become the main focus in the design of state-of-the-art border security solutions. While respective research in the field of multimedia vision has been centred around improving quality and accuracy of identity recognition, the impact of such technologies upon society and legal regulations still remains a topic unaddressed, specifically within the engineering community. Research in technology can and in some respect must include collaboration with social sciences and social practice. Building on participation in the EU funded research project PERSONA [18] (Privacy, Ethical, Regulatory and SOcial No-gate crossing point solutions Acceptance), authors of this paper look at the challenges associated with biometrics-based solutions in no-gate border crossing point scenarios. This included the procedures needed for the assessment of their social, ethical, privacy and regulatory acceptance, particularly in view of the impact on both, the passengers and border control authorities as well as the potential pitfalls of biometric technology due to fraudulent activities. In consultation with the collaborating border control authorities, the paper reports on the formal assessment of biometric technologies for real-world acceptance to cope with the increasing demand of global travellers crossing state borders.

Effect of ClAlPcS(2) photodynamic and sonodynamic therapy on HeLa cells

Photodynamic therapy (PDT) uses photosensitive substance to provoke a cytotoxic reaction causing a cell damage or cell death. The substances, photosensitizers, are usually derivates of porphyrine or phtalocyanine. Photosensitizers must be activated by light in order to produce reactive oxygen species, mainly singlet oxygen. Sonodynamic therapy (SDT) utilizes ultrasound to enhance a cytotoxic effects of compounds called sonosensitizers. In this study we investigated photodynamic and sonodynamic effect of chloraluminium phtalocyanine disulfonate (ClAlPcS(2)) on HeLa cells. DNA damage, cell viability and reactive oxygen species (ROS) production were assessed to find whether the combination of PDT and SDT inflicts HeLa cells more than PDT alone. We found that the combined therapy increases DNA fragmentation, enhances ROS production and decreases cell survival. Our results indicate that ClAlPcS(2) can act as a sonosentitiser and combined with PDT causes more irreversible changes to the cells resulting in cell death than PDT alone.

Pars plana vitrectomy versus scleral buckling for repairing simple rhegmatogenous retinal detachments

BACKGROUND

Rhegmatogenous retinal detachment (RRD) is a separation of neurosensory retina from the underlying retinal pigment epithelium. It is caused by retinal tears, which let fluid pass from the vitreous cavity to the subretinal space. Pars plana vitrectomy (PPV), scleral buckling surgery and pneumatic retinopexy are three accepted management strategies whose efficacy remains controversial. Pneumatic retinopexy is considered in a separate Cochrane Review.

OBJECTIVES

The primary objective of this review was to assess the efficacy of PPV versus scleral buckling for the treatment of simple RRD (primary RRD of any extension with up to two clock hours large break(s) regardless of their anterior/posterior localisation) in people with (phakia) or without (aphakia) a natural lens in the eye, or with an artificial lens (pseudophakia). A secondary objective was to assess any data on economic and quality-of-life measures.

SEARCH METHODS

We searched CENTRAL, which contains the Cochrane Eyes and Vision Trials Register; MEDLINE; Embase; LILACS; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 5 December 2018.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing PPV versus scleral buckling surgery with at least three months of follow-up.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology. Two review authors independently extracted the data and study characteristics from the studies identified as eligible after initial screening. We considered the following outcomes: primary retinal reattachment, postoperative visual acuity, final anatomical success, recurrence of retinal detachment, number of interventions needed to achieve final anatomical success, quality of life and adverse effects. We assessed the certainty of evidence using GRADE.

MAIN RESULTS

This review included 10 RCTs (1307 eyes of 1307 participants) from Europe, India, Iran, Japan and Mexico, which compared PPV and scleral buckling for RRD repair. Two of these 10 studies compared PPV combined with scleral buckling with scleral buckling alone (54 participants). All studies were high or unclear risk of bias on at least one domain. Five studies were funded by non-commercial sources, while the other five studies did not report source of funding.There was little or no difference in the proportion of participants who achieved retinal reattachment at least 3 months after the operation in the PPV group compared to those in the scleral buckling group (risk ratio (RR) 1.07, 95% confidence intervals (CI) 0.98 to 1.16; 9 RCTs, 1261 participants, low-certainty evidence). Approximately 67 in every 100 people treated with scleral buckling had retinal reattachment by 3 to 12 months. Treatment with PPV may result in 4 more people with retinal reattachment in every 100 people treated (95% confidence interval (CI) 2 fewer to 11 more).There was no evidence of any important difference in postoperative visual acuity between participants in the PPV group compared to those in the scleral buckling group (mean difference (MD) 0.00 logMAR, 95% CI -0.09 to 0.10, 6 RCTs, 1138 participants, low-certainty evidence).There was little or no difference in final anatomical success between participants in the PPV group and scleral buckling group (RR 1.01, 95% CI 0.99 to 1.04, 9 RCTs, 1235 participants, low-certainty evidence). There were 94 out of 100 people treated with control (scleral buckling) that achieved final anatomical success compared to 96 out of 100 in the PPV group.Retinal redetachment was reported in fewer participants in the PPV group compared to the scleral buckling group (RR 0.75 (95% CI 0.59 to 0.96, 9 RCTs, 1320 participants, low-certainty evidence). Approximately 28 in every 100 people treated with scleral buckling had retinal detachment by 3 to 36 months. Treatment with PPV may result in seven fewer people with retinal detachment in every 100 people treated (95% CI 1 to 11 fewer).Participants treated with PPV on average needed fewer interventions to achieve final anatomical success but the difference was small and data were skewed (MD -0.20, 95% CI -0.34 to -0.06, 2 RCTs, 682 participants, very low-certainty evidence).Very low-certainty evidence on quality of life suggested that more people in the PPV group were "satisfied with vision" compared with the scleral buckling group (RR 6.22, 95% CI 0.88 to 44.09, 1 RCT, 32 participants).All included studies reported adverse effects, however, it was not always clear whether they were reported as number of participants or number of adverse effects. Cataract development or progression was more prevalent in the PPV group (RR 1.71, 95% CI 1.45 to 2.01), choroidal detachment was more prevalent in the scleral buckling group (RR 0.19, 95% CI 0.06 to 0.65) and new/iatrogenic breaks were observed only in the PPV group (RR 8.21, 95% CI 1.91 to 35.21). Estimates of the relative frequency of other adverse effects, including postoperative proliferative vitreoretinopathy, postoperative increase in intraocular pressure, development of cystoid macular oedema, macular pucker and strabismus were imprecise. Evidence for adverse effects was low-certainty evidence.

AUTHORS' CONCLUSIONS

Low- or very low-certainty evidence indicates that there may be little or no difference between PPV and scleral buckling in terms of primary success rate, visual acuity gain and final anatomical success in treating primary RRD. Low-certainty evidence suggests that there may be less retinal redetachment in the PPV group. Some adverse events appeared to be more common in the PPV group, such as cataract progression and new iatrogenic breaks, whereas others were more commonly seen in the scleral buckling group such as choroidal detachment.

Evaluation of intraocular lens position during phacoemulsification using intraoperative spectral-domain optical coherence tomography

PURPOSE

To assess the position of intraocular lenses (IOLs) at the end of standard phacoemulsification with intraoperative spectral-domain optical coherence tomography (SD-OCT).

SETTINGS

Department of Ophthalmology, Rudolf Foundation Hospital, Vienna, Austria.

DESIGN

Prospective case series.

METHODS

Standard phacoemulsification with IOL implantation was performed. The Rescan 700 SD-OCT system was used for intraoperative imaging. The anterior segment of the eye was scanned using SD-OCT at the end of the surgery. The distance from the IOL optic center and the IOL optic edge to the posterior capsule was measured postoperatively using graphic software.

RESULTS

The study comprised 74 patients (101 eyes). The mean axial length was 23.97 mm (range 21.43 to 28.61 mm). The mean IOL power was 20.39 diopters (D) (range 6.5 to 27.5 D). Contact between the IOL and posterior capsule was absent in 88 cases (87.13%), and partial or full contact was present in 13 cases (12.87%). The mean distance between the IOL central optic and posterior capsule was 0.71 pixel (range 0.06 to 1.38 pixels) in 99 cases (98.02%). In 42 cases (57.53%), partial contact between the IOL edges and the posterior capsule was noticed. The mean distance between the IOL edge and posterior capsule was 0.21 pixel (range 0.04 to 0.92 pixel).

CONCLUSIONS

Intraoperative SD-OCT facilitated the imaging of IOL position during standard phacoemulsification. Contact between the IOL central optic and posterior capsule at the end of the surgery occurred rarely. Improved IOL design should be considered.

FINANCIAL DISCLOSURE

Drs. Binder and Glittenberg are consultants to Carl Zeiss Meditech AG. None of the other authors has a financial or proprietary interest in any material or method mentioned.

State of the art und Zukunft der Vitrektomie – Techniken und Instrumente

Hintergrund

Durch die Einführung der Pars plana Vitrektomie ist eine Vielzahl von vitreoretinalen Erkrankungen behandelbar geworden. Kontinuierliche Verbesserungen der Geräte, Instrumente und zusätzliche Hilfsmittel sowie neue Techniken kennzeichnen den enormen Fortschritt der vitreoretinalen Chirurgie.

Methoden

In einer Literaturübersicht werden die Operationstechniken verschiedenster vitreoretinaler Eingriffe analysiert. Sofern aufgrund aktueller Entwicklungen verschiedene Optionen in der Operationstechnik bestehen, werden Experten auf dem Gebiet der vitreoretinalen Chirurgie über ihre Erfahrung und ihre Empfehlung befragt.

Ergebnisse

Die 20 Gauge Pars plana Vitrektomie wurde größtenteils durch die Verwendung von Trokaren (23, 25 und 27 Gauge) mit entsprechenden Instrumenten mit kleinerem Durchmesser abgelöst. Die Pars plana Vitrektomie ist nahtlos möglich, trotzdem kann es notwendig sein, eine zusätzliche Sicherung der Wunde mit einer Naht durchzuführen, um Leckage und Hypotonie zu vermeiden. Die Visualisierung des Glaskörpers erfolgt zunehmend mit Triamcinolon, epiretinale Gliosen und die Membrana limitans interna werden routinemäßig mit Vitalfarbstoffen dargestellt. Bei der Operationstechnik beim Makulaforamen und bei der Ablatio retinae zeigen sich sowohl bei aktuellen Publikationen als auch unter den Experten Variationen.

Schlussfolgerungen

Die Pars plana Vitrektomie hat sich aufgrund der Weiterentwicklung speziell im Bereich der Trokar Systeme, Vitrektome, der Weitwinkel-Beobachtungssysteme sowie dank neuer Techniken zu einer essentiellen OP-Methode für ein weites Indikationsspektrum entwickelt. Dies ist die Basis der Behandlung verschiedenster vitreoretinaler Erkrankungen mit immer weniger Operationstrauma, weniger intraoperativen und postoperativen Komplikationen und gutem Therapieerfolg. Unterschiedliche Operationsvarianten, neue Techniken und die Weiterentwicklung der Geräte und Instrumente sind die Basis für einen auch zukünftigen Fortschritt der Pars plana Vitrektomie.

Intraoperative optical coherence tomography assisted analysis of pars Plana vitrectomy for retinal detachment in morning glory syndrome: a case report

BACKGROUND

The pathogenesis of non-rhegmatogenous retinal detachment (non-RRD) associated with morning glory syndrome (MGS) is not established, as well as best surgical approach to treat RD. Our purpose was to analyse intraoperative optical coherence tomography data (iOCT) in all steps of pars plana vitrectomy (PPV) for non-RRD in MGS, in order to follow pathophysiological aspects of the disease and to understand the tissues behaviour during surgical workflow.

CASE PRESENTATION

Intraoperative spectral domain optical coherent tomography (iSD-OCT) assisted PPV using Rescan 700 (Carl Zeiss Meditech, Jena, Germany) with epiretinal membrane (ERM) and internal retinal membrane (ILM) peeling, and air endotamponade was performed on the only eye of a 21 years old female with non-RRD associated with MGS. BCVA, pre-, intra- and postoperative OCT were performed along with standard ocular examination. iOCT video and snapshots were analysed intra- and postoperatively using post-processing approach using graphic software. The progression of non-RRD resulted in best corrected visual acuity (BCVA) decrease from 0.8 to 0.2. Triamcinolone enhanced iOCT imaging revealed strong vitreous traction and adhesion above the macula and optic disc. Internal limiting membrane was peeled under iOCT control to prevent the peeling of inner layers of the retinal schisis. No retinal break was detected, and only air endotamponade was performed. The retina reattached during first 4 weeks of follow-up with gradual resolution of intraretinal- and subretinal fluid, and remained stable in 12 months. BCVA improved to 0.8.

CONCLUSION

Based on iSD-OCT findings we assume that non-RRD in this case of MGS is caused primarily by the vitreous traction with further possible formation of the retinal breaks. Retinal reattachment reached only with air endotamponade strongly advocates the tractional component of non-RRD and retinal schisis assotiated with MGS. Early PPV for central non-RRD and retinal schisis with the use of iOCT can be performed in more safe and controlled manner and has to be considered to reduce the risk of retinal break formation and to prevent the central vision loss.

Primary Retinal Detachment Surgery: Changes in Treatment and Outcome in an Austrian Tertiary Eye Center

PURPOSE

The surgery of choice for primary retinal detachment (RD) has shifted towards primary vitrectomy (PPV) in recent years. In this study, 2 cohorts of consecutive patients, treated by 8 retinal surgeons within a 7-year time span were compared.

METHODS

Baseline demographic data, surgical procedure, and outcome of patients with primary RD surgery between January 2007 and December 2008 (group 1, G1) and January 2012 and December 2013 (group 2, G2) were compared. Statistical analysis included univariate comparisons (Wilcoxon rank-sum test and χ2 test) and ANCOVA (analysis of covariance) models.

RESULTS

The most common primary procedure was scleral buckling (n = 92, 66%) in G1 and PPV (n = 252, 85%) in G2 (p < 0.0001). Primary anatomical success rates were comparable (89%). The percentage of eyes with best corrected visual acuity (BCVA) equal or better than 0.3 logMAR (6/12) at final follow-up was significantly higher in G2 (61%, n = 156) compared to 49% (n = 68) in G1 (p = 0.0223).

CONCLUSIONS

Within 7 years, a complete trend reversal could be observed shifting the primary surgical approach for RD towards PPV. Primary and final anatomical success rates were comparable, yet the later group experienced a significantly higher gain in BCVA, which approves the change in treatment regimen.