Swept Source-Optical Coherence Tomography Angiography for Management of Secondary Choroidal Neovascularization in Punctate Inner Choroidopathy

The purpose was to demonstrate the diagnostic and therapeutic feasibility of swept source-optical coherence tomography angiography (SS-OCTA) by picturing neovascular changes secondary to a rare white dot syndrome following long-term intravitreal ranibizumab (IVR). A 28-year-old Caucasian myopic female presented with visual loss in her right eye only. The clinical examination and multimodal imaging including spectral domain (SD)-OCT, blue-peak autofluorescence, fluorescein, and indocyanine green angiography (HRA Spectralis, Heidelberg Engineering; Heidelberg, Germany) as well as SS-OCTA (DRI Triton, Topcon; Tokyo, Japan) led to the diagnosis of idiopathic punctate inner choroidopathy with secondary subfoveal choroidal neovascularization (CNV). In addition to oral corticosteroids, a pro re nata regimen with IVR was initiated and guided by repeated SD-OCT and SS-OCTA. Six IVR were administered based on functional SS-OCTA en face scans illustrating vessel transformation and downsizing of the CNV area while SD-OCT B-scans were inconclusive as indirect signs of activity were absent throughout the follow-up period. SS-OCTA provided new possibilities for monitoring vessel development. IVR was managed based on vessel density as displayed by SS-OCTA.

Systematic analysis of leisler's bat Nyctalus leisleri (Kuhl, 1817) captured from FATA region, Pakistan

Extensive field surveys were carried out to explore the distribution of Leisler's Bat Nyctalus leisleri (Kuhl, 1819) in selected area of FATA regions, Pakistan. Specimens of Leisler's Bat Nyctalus leisleri (Kuhl, 1819) (n5) were collected from Kurram Agency (Shublan) (N33.8229788 E70.1634414) at elevation 1427m and Khyber Agency (Landi Kotel) (N34.0909899 E71.1457517) at elevation 1091m for two years survey extending from May 2013 through August 2015. The mean head and body length, hind foot length, ear length and tail length the Nyctalus leisleri specimens captured from the study area was 65.08 ± 1.58 mm, 44.06 ± 0.52 mm, 8.38 ± 0.60 mm, 13.20 ± 0.99 mm and 39.46 ± 1.46 mm, respectively. For molecular analysis the sequences of COI gene were obtained and analyzed. The mean intraspecific divergences of Nyctalus leisleri was 0.04%. The mean interspecific divergences of Nyctalus noctula and Nyctalus leisleri was 0.2%. The mean concentration of each nucleotides was A = (26.3%), T = (32.8%), G = (15.9%) and C = (25.0%). The mean A+T contents were 59.2%and C+G were 40.9%. In the phylogenetic tree Nyctalus leisleri and Nyctalus noctula clustered with significant bootstrap support value.

3D mechanical characterization of single cells and small organisms using acoustic manipulation and force microscopy

Quantitative micromechanical characterization of single cells and multicellular tissues or organisms is of fundamental importance to the study of cellular growth, morphogenesis, and cell-cell interactions. However, due to limited manipulation capabilities at the microscale, systems used for mechanical characterizations struggle to provide complete three-dimensional coverage of individual specimens. Here, we combine an acoustically driven manipulation device with a micro-force sensor to freely rotate biological samples and quantify mechanical properties at multiple regions of interest within a specimen. The versatility of this tool is demonstrated through the analysis of single Lilium longiflorum pollen grains, in combination with numerical simulations, and individual Caenorhabditis elegans nematodes. It reveals local variations in apparent stiffness for single specimens, providing previously inaccessible information and datasets on mechanical properties that serve as the basis for biophysical modelling and allow deeper insights into the biomechanics of these living systems.

Effect of different protein based feed on the growth of mahseer

For the proper growth of fish, it is necessary to feed the fish with a proper and balanced diet. A study was conducted to find out the effect of different protein-based diets on fingerlings of Tor putitora (mahseer). A feed with dietary protein levels of 35%, 40%, 45%, and 50% were prepared. The effect of different protein-based feed on weight gain, standard growth rate (SGR), food conversion ratio (FCR), percent weight gain, food conversion efficiency (FCE), and protein efficiency ratio (PER) was studied. An increase was observed in the growth rate with an increase in protein concentration up to 45%. The fingerlings fed a 45% protein diet shown the highest growth, followed by 50%, 40%, and 35%. The SGR value was greatest for 45% protein diet (8.56) followed by 50% and 40%, while the least values were observed for 35% protein feed (1.57). The same trend was observed for FCE. The highest PER values was observed in fishes fed 45% protein-based feed (0.65) followed by 50% (0.56), 40% (0.38) and35% (0.17). The food conversion ratio was lowest for 45% protein diet (3.41), while the greatest for 35% protein feed (16.85). It was concluded that a 45% protein-based diet was the best feed formulation for higher production of Tor putitora. However, research on the same percentage of protein diet is recommended for yearlings.

Comparison of macular neovascularization lesion size by the use of Spectral-Domain Optical Coherence Tomography Angiography and Swept-Source Optical Coherence Tomography Angiography versus Indocyanine Green Angiography

PURPOSE

To compare the lesion sizes of macular neovascularization (MNV) imaged with spectral-domain (SD) and swept-source (SS) optical coherence tomography angiography (OCTA) as well as indocyanine green angiography (ICGA).

METHODS

In this prospective, observational case series, patients showing a secured diagnosis of MNV on ICGA or Fluorescein Angiography, were imaged by SD-OCTA and SS-OCTA on the same day. Lesion size was measured on 3 × 3-mm² and 6 × 6-mm² scans using the Maestro 2 SD-OCTA (Topcon Corporation, Tokyo Japan) and the Triton SS-OCTA device (Topcon Corporation, Tokyo Japan) and compared to ICGA (Spectralis HRA, Heidelberg, Germany).

RESULTS

Twenty eyes from 20 patients (11 females, 55%) were enrolled. The neovascularization area measured on 6 × 6-mm² SD-OCTA was lower compared to that outlined on SS-OCTA, however, not reaching statistical significance (p = 0.094). Regarding 3 × 3-mm² measurements, the median lesion sizes between the two OCTA devices were comparable (p = 0.492). Indocyanine green angiography depicted a larger lesion area than both OCTA devices, however, not reaching statistical significance.

CONCLUSION

SD-OCTA tends to show smaller areas of MNV extension than SS-OCTA regarding 6 × 6 mm² scans. The lesion size of MNV can be very well compared between the different devices, emphasizing the use of OCTA for monitoring neovascular area. Lesion measurements on SS-OCTA correlate better with ICGA than SD-OCTA.

Bio-inspired Acousto-magnetic Microswarm Robots with Upstream Motility

The ability to propel against flows, i.e., to perform positive rheotaxis, can provide exciting opportunities for applications in targeted therapeutics and non-invasive surgery. To date, no biocompatible technologies exist for navigating microparticles upstream when they are in a background fluid flow. Inspired by many naturally- occurring microswimmers such as bacteria, spermatozoa, and plankton that utilize the non-slip boundary conditions of the wall to exhibit upstream propulsion, here, we report on the design and characterization of self-assembled microswarms that can execute upstream motility in a combination of external acoustic and magnetic fields. Both acoustic and magnetic fields are safe to humans, non-invasive, can penetrate deeply into the human body, and are well-developed in clinical settings. The combination of both fields can overcome the limitations encountered by single actuation methods. The design criteria of the acoustically-induced reaction force of the microswarms, which is needed to perform rolling-type motion, are discussed. We show quantitative agreement between experimental data and our model that captures the rolling behaviour. The upstream capability provides a design strategy for delivering small drug molecules to hard-to-reach sites and represents a fundamental step toward the realization of micro- and nanosystem-navigation against the blood flow.

Mechanically interlocked 3D multi-material micromachines

Metals and polymers are dissimilar materials in terms of their physicochemical properties, but complementary in terms of functionality. As a result, metal-organic structures can introduce a wealth of novel applications in small-scale robotics. However, current fabrication techniques are unable to process three-dimensional metallic and polymeric components. Here, we show that hybrid microstructures can be interlocked by combining 3D lithography, mold casting, and electrodeposition. Our method can be used to achieve complex multi-material microdevices with unprecedented resolution and topological complexity. We show that metallic components can be combined with structures made of different classes of polymers. Properties of both metals and polymers can be exploited in parallel, resulting in structures with high magnetic responsiveness, elevated drug loading capacity, on-demand shape transformation, and elastic behavior. We showcase the advantages of our approach by demonstrating new microrobotic locomotion modes and controlled agglomeration of swarms.

Mechanically interlocking dissimilar materials, such as metals and polymers, is a challenging yet promising pathway for designing and fabricating complex systems on the small scale. Here, the authors report a novel interlocking fabrication scheme and showcase the fabrication of microrobots via 3D-lithography.

Correction to: Drusen characteristics of type 2 macular neovascularization in age-related macular degeneration

An amendment to this paper has been published and can be accessed via the original article.

Drusen characteristics of type 2 macular neovascularization in age-related macular degeneration

Background

Type 2 macular neovascularization (MNV) is supposed to be a rare condition in age-related macular degeneration (AMD). The main purpose of this study was to assess accompanying factors of type 2 MNV in AMD.

Methods

Retrospective data analysis of eyes previously diagnosed with neovascular AMD in a tertiary eye care center (Medical Retina Unit, Rudolf Foundation Hospital, Vienna, Austria) between June 2008 and December 2017. Drusen subtypes, fibrosis, atrophy and subfoveal choroidal thickness (SFCT) of both eyes in patients with type 2 MNV lesions were categorized based on multimodal imaging.

Results

Type 2 MNV was diagnosed in 27 (3.2%) of 835 eyes (749 patients). Drusen characteristics in type 2 MNV were observed as followed: drusen < 63 μm in 2 eyes (7.4%), drusen ≥63 μm in 10 eyes (37%), subretinal drusenoid deposits (SDD) in 8 eyes (29.6%), cuticular drusen in 2 eye (7.4%) and no drusen were evident in 10 eyes (37%). Drusen distribution in 23 fellow eyes was detected as followed: drusen < 63 μm in 2 eyes (8.7%), drusen ≥63 μm in 9 eyes (39.1%), SDD in 5 eyes (21.7%), cuticular drusen in 1 eye (4.3%) and no drusen were evident in 9 eyes (39.1%). Mean SFCT was 140 ± 49 μm in affected eyes and 152 ± 41 μm in the fellow eyes. Patients with drusen or SDD were significantly younger (mean 70.88 ± 6.85, p = 0.04) than patients without deposits (mean 77.40 ± 5.74).

Conclusions

Type 2 MNV remains a rare entity in AMD. It was frequently seen in the absence of drusen, a hallmark of AMD. These findings contribute to the heterogeneity of phenotypes related to pure type 2 lesions.

Magnetic cilia carpets with programmable metachronal waves

Metachronal waves commonly exist in natural cilia carpets. These emergent phenomena, which originate from phase differences between neighbouring self-beating cilia, are essential for biological transport processes including locomotion, liquid pumping, feeding, and cell delivery. However, studies of such complex active systems are limited, particularly from the experimental side. Here we report magnetically actuated, soft, artificial cilia carpets. By stretching and folding onto curved templates, programmable magnetization patterns can be encoded into artificial cilia carpets, which exhibit metachronal waves in dynamic magnetic fields. We have tested both the transport capabilities in a fluid environment and the locomotion capabilities on a solid surface. This robotic system provides a highly customizable experimental platform that not only assists in understanding fundamental rules of natural cilia carpets, but also paves a path to cilia-inspired soft robots for future biomedical applications.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY FOR THE DETECTION OF SECONDARY CHOROIDAL NEOVASCULARIZATION IN VITELLIFORM MACULAR DYSTROPHY

PURPOSE

Optical coherence tomography angiography (OCTA) is used to assess vascular abnormality in advanced stage vitelliform macular dystrophy (VMD2).

METHODS

Multimodal imaging including spectral domain (SD) OCT, autofluorescence (AF), fluorescein (FA) and indocyanine green angiography (ICGA) as well as optical coherence tomography angiography were performed.

PATIENTS

Two eyes in one young patient with diagnosed vitelliform macular dystrophy were investigated for progressive visual dysfunction.

RESULTS

Optical coherence tomography angiography identified neovascular formation within the outer retina and the choriocapillaris respectively while all other imaging methods were inconclusive.

CONCLUSION

Optical coherence tomography angiography was superior to conventional angiography in the detection of choroidal neovascularization (CNV) in advanced retinal disorders like vitelliform macular dystrophy.

P250 Evaluation of coronary endothelial dysfunction by positron emission tomography: does gender make a difference

Funding Acknowledgements

None

Introduction

Endothelial dysfunction (ED) manifested as abnormality of coronary microvasculature is associated with poor prognosis in patients presenting with chest pain. ED can be noninvasively evaluated by assessment of coronary flow reserve with positron emission tomography (PET). Studies directly comparing ED in men and women are limited. The aim of this study is to compare gender differences in ED as measured by CFR on PET myocardial perfusion imaging.

Methods

All the consecutive patients referred to PET-MPI between May 2011 and June 2018 were reviewed. Patient without known CAD who had normal perfusion were included in the analysis. Patient with abnormal electrocardiogram, significant transient ischemic dilatation, low left ventricular ejection fraction and high calcium score (&gt;1000 AU) and renal failure were excluded. CFR is calculated as the ratio of stress/rest myocardial blood flow. CFR &lt; 2 was considered as abnormal indicating the presence of ED.

Results

1711 patients were included in the analysis (mean age 60.2 ± 10 year, 68% females). Females were older and had higher BMI and diabetes (DM). Both resting and peak myocardial blood flow (MBF) was higher in females (1.16 vs 1.02 (p &lt; 0.0001)) and 3.26 vs 2.9 (p &lt; 0.001)0 respectively.  Around 68% of males had abnormal CFR (&lt;2) compared to 63% of females (p = 0.05). After adjusting for the confounders, female gender was associated with higher peak MBF (Hazard ratio 0.29, 95% CI 0.19 –0.40, p &lt; 0.001) and lower chance of having ED (Hazard ratio -0.15, 95% CI -0.29 - -0.005, p = 0.049)

Conclusions

Endothelial dysfunction as measured noninvasively by CFR on PET is prevalent among both sexes. Higher level of peak MBF in females may call for a different cut-off for abnormal CFR in women. Outcome studies are required to evaluate the clinical utility and prognostic value of such a cut-off.

Magnetic quadrupole assemblies with arbitrary shapes and magnetizations

Magnetic dipole-dipole interactions govern the behavior of magnetic matter across scales from micrometer colloidal particles to centimeter magnetic soft robots. This pairwise long-range interaction creates rich emergent phenomena under both static and dynamic magnetic fields. However, magnetic dipole particles, from either ferromagnetic or paramagnetic materials, tend to form chain-like structures as low-energy configurations due to dipole symmetry. The repulsion force between two magnetic dipoles raises challenges for creating stable magnetic assemblies with complex two-dimensional (2D) shapes. In this work, we propose a magnetic quadrupole module that is able to form stable and frustration-free magnetic assemblies with arbitrary 2D shapes. The quadrupole structure changes the magnetic particle-particle interaction in terms of both symmetry and strength. Each module has a tunable dipole moment that allows the magnetization of overall assemblies to be programmed at the single module level. We provide a simple combinatorial design method to reach both arbitrary shapes and arbitrary magnetizations concurrently. Last, by combining modules with soft segments, we demonstrate programmable actuation of magnetic metamaterials that could be used in applications for soft robots and electromagnetic metasurfaces.

P6158Prognostic value of non-obstructive coronary artery disease detected on coronary computed tomography angiography among subjects with suspected coronary artery disease

Introduction

Coronary Computed Tomography Angiography (CTA) is an established technique for the detection of coronary artery disease (CAD). However, the prognostic value of non-obstructive CAD is not well defined. Thus, the aim of this analysis is to determine the prognostic value of non-obstructive CAD detected on CTA.

Methods

In the Multi-Center Multi-Ethnic Coronary Computed Tomography Angiography (MECCA) Study, 3209 subjects without known CAD underwent CTA. Patients with obstructive CAD were excluded from this analysis. Patients with ≤70% luminal coronary artery stenosis in vessels other than the left main were classified to have non-obstructive CAD while patients without any plaque were considered to have normal CTA. Patients were followed up for a median duration of 3.4 years for all-cause mortality (ACM). Multivariable Cox models were used to determine the independent predictors of event-free survival.

Results

A total of 1455 subjects had non-obstructive CAD and 1382 subjects had normal coronary arteries. Subjects with non-obstructive CAD were older (55.9±11 vs 46.2±11 years, p<0.001) and more likely to be males (56.8% vs 50.5%, p=0.001) and had more prevalent traditional risk factors. A total of 83 ACM were observed (4.4% in the non-obstructive group and 1.3% in the normal group, p<0.001). Patients with clinical events were older (61.8±14 vs 50.9±12 years, p<0.001) and have more prevalence of DM (42.2% vs 31.4%, p=0.031) and HTN (72.3% vs 54.3%, p=0.001). In Multivariable Cox models, non-obstructive CAD was associated with increased event rate (Hazard ratio 1.75, 95% CI 1.01–3.01, p=0.45).

Kaplan-Meier Survival Curves

Conclusions

Patients with non-obstructive CAD on CTA have a higher rate of all-cause mortality. Non-obstructive CAD on CTA enhances risk stratification among subjects suspected with CAD and should call for more aggressive guidelines directed medical therapy.

Acknowledgement/Funding

None

Development of Secondary Choroidal Neovascularization in Focal Choroidal Excavation of Punctate Inner Choroidopathy

Purpose: To elaborate a case of focal choroidal excavation (FCE) in punctate inner choroidopathy (PIC) complicated by secondary choroidal neovascularization (CNV) based on multimodal imaging findings.Methods: In this retrospective case report, multimodal imaging including near-infrared reflectance, blue peak autofluorescence, spectral domain-optical coherence tomography (OCT), fluorescein and indocyanine green angiography (Heidelberg Engineering GmbH, Germany), and swept source-OCT angiography (SS-OCTA; Topcon Corporation, Japan) was performed.Patients: A 27-year-old moderate myopic woman presented with inactive CNV of unknown origin in her left eye, which had been previously treated with intravitreal anti-vascular endothelial growth factor.Results: Multimodal imaging revealed PIC as the causative disease and systemic corticosteroids were administered. Similar complaints 13 months later showed new CNV formation at the already documented FCE. No sign of PIC could be detected at follow-up.Conclusion: This well-documented case highlighted FCE as the preferential location for CNV development in PIC with multimodal imaging emphasizing a chorioretinal entity.Summary: This case report demonstrated the clinical course of focal choroidal excavation in a patient initially diagnosed with punctate inner choroidopathy complicated by choroidal neovascularization and its treatment response, well documented by multimodal imaging including optical coherence tomography angiography.