2-Desaza-annomontine (C81) impedes angiogenesis through reduced VEGFR2 expression derived from inhibition of CDC2-like kinases.

Angiogenesis is a crucial process in the progression of various pathologies, like solid tumors, wet age-related macular degeneration, and chronic inflammation. Current anti-angiogenic treatments still have major drawbacks like limited efficacy in diseases that also rely on inflammation. Therefore, new anti-angiogenic approaches are sorely needed, and simultaneous inhibition of angiogenesis and inflammation is desirable. Here, we show that 2-desaza-annomontine (C81), a derivative of the plant alkaloid annomontine previously shown to inhibit endothelial inflammation, impedes angiogenesis by inhibiting CDC2-like kinases (CLKs) and WNT/ß-catenin signaling. C81 reduced choroidal neovascularization in a laser-induced murine in vivo model, inhibited sprouting from vascular endothelial growth factor A (VEGF-A)-activated murine aortic rings ex vivo, and reduced angiogenesis-related activities of endothelial cells in multiple functional assays. This was largely phenocopied by CLK inhibitors and knockdowns, but not by inhibitors of the other known targets of C81. Mechanistically, CLK inhibition reduced VEGF receptor 2 (VEGFR2) mRNA and protein expression as well as downstream signaling. This was partly caused by a reduction of WNT/ß-catenin pathway activity, as activating the pathway induced, while ß-catenin knockdown impeded VEGFR2 expression. Surprisingly, alternative splicing of VEGFR2 was not detected. In summary, C81 and other CLK inhibitors could be promising compounds in the treatment of diseases that depend on angiogenesis and inflammation due to their impairment of both processes.

Clinical value of neuroimaging indicators of intracranial hypertension in patients with cerebral venous thrombosis.

PURPOSE: Intracranial hypertension (IH) frequently complicates cerebral venous thrombosis (CVT). Distinct neuroimaging findings are associated with IH, yet their discriminative power, reversibility and factors favoring normalization in prospective CVT patients are unknown. We determined test performance measures of neuroimaging signs in acute CVT patients, their longitudinal change under anticoagulation, association with IH at baseline and with recanalization at follow-up. METHODS: We included 26 consecutive acute CVT patients and 26 healthy controls. Patients were classified as having IH based on CSF pressure > 25 cmH2O and/or papilledema on ophthalmological examination or ocular MRI. We assessed optic nerve sheath diameter (ONSD), optic nerve tortuousity, bulbar flattening, lateral and IVth ventricle size, pituitary configuration at baseline and follow-up, and their association with IH and venous recanalization. RESULTS: 46% of CVT patients had IH. ONSD enlargement > 5.8 mm, optic nerve tortuousity and pituitary grade ≥ III had highest sensitivity, ocular bulb flattening and pituitary grade ≥ III highest specificity for IH. Only ONSD reliably discriminated IH at baseline. Recanalization was significantly associated with regressive ONSD and pituitary grade. Other neuroimaging signs tended to regress with recanalization. After treatment, 184.9 ± 44.7 days after diagnosis, bulbar flattening resolved, whereas compared with controls ONSD enlargement (p < 0.001) and partially empty sella (p = 0.017), among other indicators, persisted. CONCLUSION: ONSD and pituitary grading have a high diagnostic value in diagnosing and monitoring CVT-associated IH. Given their limited sensitivity during early CVT and potentially persistent alterations following IH, neuroimaging indicators can neither replace CSF pressure measurement in diagnosing IH, nor determine the duration of anticoagulation.

Artificial Intelligence to Detect Papilledema from Ocular Fundus Photographs.

BACKGROUND: Nonophthalmologist physicians do not confidently perform direct ophthalmoscopy. The use of artificial intelligence to detect papilledema and other optic-disk abnormalities from fundus photographs has not been well studied. METHODS: We trained, validated, and externally tested a deep-learning system to classify optic disks as being normal or having papilledema or other abnormalities from 15,846 retrospectively collected ocular fundus photographs that had been obtained with pharmacologic pupillary dilation and various digital cameras in persons from multiple ethnic populations. Of these photographs, 14,341 from 19 sites in 11 countries were used for training and validation, and 1505 photographs from 5 other sites were used for external testing. Performance at classifying the optic-disk appearance was evaluated by calculating the area under the receiver-operating-characteristic curve (AUC), sensitivity, and specificity, as compared with a reference standard of clinical diagnoses by neuro-ophthalmologists. RESULTS: The training and validation data sets from 6779 patients included 14,341 photographs: 9156 of normal disks, 2148 of disks with papilledema, and 3037 of disks with other abnormalities. The percentage classified as being normal ranged across sites from 9.8 to 100%; the percentage classified as having papilledema ranged across sites from zero to 59.5%. In the validation set, the system discriminated disks with papilledema from normal disks and disks with nonpapilledema abnormalities with an AUC of 0.99 (95% confidence interval [CI], 0.98 to 0.99) and normal from abnormal disks with an AUC of 0.99 (95% CI, 0.99 to 0.99). In the external-testing data set of 1505 photographs, the system had an AUC for the detection of papilledema of 0.96 (95% CI, 0.95 to 0.97), a sensitivity of 96.4% (95% CI, 93.9 to 98.3), and a specificity of 84.7% (95% CI, 82.3 to 87.1). CONCLUSIONS: A deep-learning system using fundus photographs with pharmacologically dilated pupils differentiated among optic disks with papilledema, normal disks, and disks with nonpapilledema abnormalities. (Funded by the Singapore National Medical Research Council and the SingHealth Duke-NUS Ophthalmology and Visual Sciences Academic Clinical Program.).

Human cytomegalovirus seropositivity is associated with reduced patient survival during sepsis.

BACKGROUND: Sepsis is one of the leading causes of death. Treatment attempts targeting the immune response regularly fail in clinical trials. As HCMV latency can modulate the immune response and changes the immune cell composition, we hypothesized that HCMV serostatus affects mortality in sepsis patients. METHODS: We determined the HCMV serostatus (i.e., latency) of 410 prospectively enrolled patients of the multicenter SepsisDataNet.NRW study. Patients were recruited according to the SEPSIS-3 criteria and clinical data were recorded in an observational approach. We quantified 13 cytokines at Days 1, 4, and 8 after enrollment. Proteomics data were analyzed from the plasma samples of 171 patients. RESULTS: The 30-day mortality was higher in HCMV-seropositive patients than in seronegative sepsis patients (38% vs. 25%, respectively; p = 0.008; HR, 1.656; 95% CI 1.135-2.417). This effect was observed independent of age (p = 0.010; HR, 1.673; 95% CI 1.131-2.477). The predictive value on the outcome of the increased concentrations of IL-6 was present only in the seropositive cohort (30-day mortality, 63% vs. 24%; HR 3.250; 95% CI 2.075-5.090; p < 0.001) with no significant differences in serum concentrations of IL-6 between the two groups. Procalcitonin and IL-10 exhibited the same behavior and were predictive of the outcome only in HCMV-seropositive patients. CONCLUSION: We suggest that the predictive value of inflammation-associated biomarkers should be re-evaluated with regard to the HCMV serostatus. Targeting HCMV latency might open a new approach to selecting suitable patients for individualized treatment in sepsis.

Pediatric Cataract Surgery: Rate of Secondary Visual Axis Opacification Depending on Intraocular Lens Type.

PURPOSE: To assess the time course of secondary visual axis opacification (VAO) leading to additional surgery after primary intraocular lens (IOL) implantation in children and to describe further surgical outcomes. Comparison of lens types. DESIGN: Single-center, retrospective analysis of children aged 1 to 14 years who underwent cataract surgery with primary IOL implantation. The surgical technique was either in-bag IOL placement with primary posterior capsulotomy and anterior vitrectomy or bag-in-lens IOL placement. We excluded eyes with visually significant ocular comorbidities. PARTICIPANTS: Total of 135 eyes of 95 children. Of these, 64 had received an acrylic 3-piece IOL, 51 had an acrylic single-piece IOL, and 20 had an acrylic single-piece bag-in-lens IOL. The median ages at surgery were 53 months (interquartile range [IQR], 35-75), 52 months (27-65), and 60 months (40-84) in the 3-piece, 1-piece, and bag-in-lens groups, respectively. METHODS: Analysis of medical records. We used the Kaplan-Meier method and a Cox proportional hazards model with predefined adjustments for age at surgery, year of surgery, and the German Index of Socioeconomic Deprivation (score by postal code) to analyze VAO-free survival by lens type. Patients were invited to attend a clinical visit to achieve longer follow-ups. MAIN OUTCOME MEASURES: The rate of survival without VAO that required clearing of the visual axis after cataract surgery with primary IOL implantation. Any other surgical complications. RESULTS: The overall median follow-up was 19 months (IQR, 3-58). There were 13 cases of VAO, occurring at a median of 10 months (IQR, 10-12) after surgery. Of these, 1 eye had a 3-piece in-bag IOL, 10 eyes had 1-piece in-bag IOLs, and 2 eyes had bag-in-lens IOLs. The adjusted hazard ratio was 32.8 (95% confidence interval [CI], 3.3-327, P = 0.003) for 1-piece acrylic IOLs and 19.6 (CI, 1.22-316, P = 0.036) for bag-in-lens IOLs, compared with 3-piece acrylic in-bag IOLs. Two eyes with bag-in-lens surgery (10%) had an iris capture. There was 1 case of endophthalmitis. We found no cases of postoperative retinal detachment or new glaucoma. CONCLUSIONS: Children with secondary VAO who required a procedure to clear the visual axis generally presented within 15 months. Opacification rates were lowest when a 3-piece acrylic IOL was used.

A randomized, open-label, multicenter study of switching to brolucizumab with or without a loading dose for patients with suboptimal anatomically controlled neovascular age-related macular degeneration-the FALCON study.

BACKGROUND: Treatment initiation with brolucizumab, a new potent anti-vascular endothelial growth factor (VEGF) agent, is typically performed with three monthly injections (loading dose) and has been well studied in treatment-naïve patients. However, no clinical data are available yet on whether or not anti-VEGF pretreated patients also benefit from a loading dose. In the clinical setting, different heterogeneous treatment patterns are used as no clinical trial has addressed this so far in a head-to-head comparison. Therefore, the FALCON study is investigating whether patients with unsatisfactory response to previous anti-VEGF treatments benefit from a loading dose at the switch to brolucizumab treatment. METHODS: FALCON is a 52-week, two-arm, randomized, open-label, multicenter, multinational study in patients with residually active neovascular age-related macular degeneration (nAMD) who will be randomized 1:1 and started with brolucizumab 6 mg loading (three monthly loading doses) or brolucizumab 6 mg non-loading (one initial injection) and consecutive treatment every 12 weeks, respectively. The primary objective is to demonstrate non-inferiority of the non-loading vs. loading arm in mean change of best-corrected visual acuity (BCVA) from baseline to the mean value at week 40 to week 52. Secondary objectives include the assessment of anatomical outcomes, treatment intervals, safety and tolerability. RESULTS: FALCON will be the first study to assess treatment initiation with an anti-VEGF agent in a switch situation with or without loading dose in patients with nAMD. CONCLUSIONS: The results will support the optimization of treatment of patients with previous unsatisfactory anti-VEGF response. Therefore, we expect to see an impact on current clinical practice which has been established for more than a decade. TRIAL REGISTRATION: Clinicaltrials.gov: NCT04679935, date of registration-22-Dec 2020; EUDRACT number: 2019-004763-53, date of registration-03 Dec 2019.

Multimode LD-pumped all-fiber Raman laser with excellent quality of 2nd-order Stokes output beam at 1019†nm.

A multimode all-fiber Raman laser enabling cascaded generation of high-quality 1019-nm output beam at direct pumping by highly-multimode (M2>30) 940-nm laser diodes has been demonstrated. The laser is made of a 100/140 graded-index fiber with special in-fiber Bragg gratings which secure sequential generation of the 1st (976 nm) and 2nd (1019 nm) Stokes orders. Comparing different 1019-nm cavity structures shows that the half-open cavity with one FBG and distributed feedback via random Rayleigh backscattering provides excellent quality (M2∼1.3) with higher slope efficiency of pump-to-2nd Stokes conversion than in the conventional 2-FBG cavity. The maximum achieved slope efficiency amounts to about 40% at output powers of up to 12 W limited by the 3rd Stokes generation.

Unusual Near-Horizon Cosmic-Ray-like Events Observed by ANITA-IV.

ANITA's fourth long-duration balloon flight in 2016 detected 29 cosmic-ray (CR)-like events on a background of 0.37_{-0.17}^{+0.27} anthropogenic events. CRs are mainly seen in reflection off the Antarctic ice sheets, creating a phase-inverted waveform polarity. However, four of the below-horizon CR-like events show anomalous noninverted polarity, a p=5.3×10^{-4} chance if due to background. All anomalous events are from locations near the horizon; ANITA-IV observed no steeply upcoming anomalous events similar to the two such events seen in prior flights.

Mining scientific advice reports on cell-based products: Insight into the nonclinical development program.

AIMS: The field of cell-based therapies for human diseases is currently evolving from promising treatment options to established therapeutic concepts. The design of the nonclinical development program for cell-based products, intended to provide a rationale for treatment and to gain insight into the safety profile, is challenging because of limitations caused by species-specificity. The elements of the nonclinical package for cell-based products were evaluated using advice reports from the European Medicines Agency database from 2013 to 2018 to identify the approach followed for nonclinical development of these products. METHODS: The number and purpose of proposed and performed in vivo studies was recorded, as well as the type and design of in vitro and in vivo studies addressing biodistribution and tumorigenicity. Subsequently, the nonclinical development program was analysed for consistency across products. RESULTS: In vivo studies for cell-based therapies were primarily aimed at proof-of-concept (75/86), followed by addressing safety (64/86), biodistribution (49/86) and tumourigenicity (46/86). No animal studies were performed or proposed by sponsors or regulators for 6/86 products which contained cell types that have been studied in humans for a relatively long time. For one-third of the products in vivo biodistribution and/or tumourigenicity studies were not considered necessary. in vivo tumourigenicity studies were regarded as having limited value. CONCLUSIONS: Compared to more conventional medicinal products, the nonclinical development program for cell-based products was more tailored and focused on proof-of-concept. For tumourigenicity an in vitro approach may suffice. Total omission of in vivo studies appears to be possible for products with sufficient clinical experience.

Thinner temporal peripapillary retinal nerve fibre layer in Stargardt disease detected by optical coherence tomography.

PURPOSE: To evaluate peripapillary retinal nerve fibre layer (RNFL) thickness measured by spectral domain optical coherence tomography (OCT) in patients with Stargardt disease (STGD). METHODS: A cross-sectional, monocentric, observational case-control study. Twenty patients (39 eyes) with ABCA4 mutations graded according to the Fishman STGD classification were included. RNFL measurement was performed using Heidelberg Spectralis SD-OCT. RNFL thickness in STGD patients was compared to age-matched data of healthy individuals provided by the device's manufacturer. A manual readjustment of the optic disc-fovea angle was performed when needed. RESULTS: The mean age at first diagnosis of STGD was 22.9 years (range 9 to 50) and 39.1 years (range 18 to 74) at the time of examination. Thirty-nine percent of eyes (15 eyes) needed manual adjustment of the optic disc-fovea angle due to malfixation of the patients during OCT. The temporal quadrant corresponding to the macula showed a RNFL 16% thinner than controls (mean - 12 µm, 95%CI - 9 to -15 µm). However, global RNFL thickness did not differ from controls due to increased RNFL thickness of 12% in the nasal sectors. Duration and stage of STGD were not correlated to thinner RNFL. CONCLUSION: STGD seems to be associated with thinner peripapillary RNFL in the sector of axons projecting to the degenerated macular area. It is yet unclear as to whether this results from anterograde transneuronal degeneration of direct injury to retinal ganglion cells.

NEGATIVE VESSEL REMODELING IN STARGARDT DISEASE QUANTIFIED WITH VOLUME-RENDERED OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PURPOSE: To quantify retinal vasculature changes in Stargardt disease1 (STGD1) with volume-rendered optical coherence tomography angiography. METHODS: Optical coherence tomography angiography volumes from healthy subjects and two subgroups of patients with STGD1 with the presence/absence of definitely decreased autofluorescence areas were compared. Optical coherence tomography angiography vessel surface area and vessel volume were measured in central zones (Z) of 1-, 2-, and 3-mm diameter. RESULTS: Twenty nine eyes of 15 patients with STGD1 (20/9 eyes with/without definitely decreased autofluorescence) and 30 eyes of 15 controls contributed data. An enlarged foveal avascular zone was found in patients with STGD1 without and even more with definitely decreased autofluorescence associated with a vessel rarefication in central and also paracentral zones with unnoticeable autofluorescence. Vessel surface area and vessel volume were reduced in both STGD1 subgroups for all zones (P < 0.0001). Stargardt disease 1 eyes when compared to without definitely decreased autofluorescence showed reduced vessel surface area and vessel volume in Z2+3 (both P < 0.05). CONCLUSION: Volume rendering of optical coherence tomography angiography in STGD1 shows a reduced retinal flow in the central macula. This is most likely secondary to loss of neurosensory tissue with disease progression and therefore not likely be favorably influenced by gene transfer and retinal pigment epithelial transplantation. Retinal blood flow assessed by 3D volume-rendered optical coherence tomography angiography could serve as surrogate marker for vascular changes of the central retina.

EPOS 4 Patients.

EPOS2020 is the 4th and most recent version of the European Position Paper on Rhinosinusitis and Nasal Polyps which was first published in 2005. It aims to provide the most up to date scientifically robust information on the topic published in the literature which has been critically analysed by an international group of clinicians drawn from all disciplines dealing with these problems together with patients. The guidelines offer evidence-based recommendations and care pathways for acute and chronic rhinosinusitis in both adults and children. Management of these diseases from the patients' perspective is an important part of EPOS2020. Not only is this included in the main document but, for the first time, we have produced a separate supplement dedicated to and in collaboration with patients, EPOS4Patients, which aims to provide information in an accessible format, to answer frequently asked questions about these diseases and their treatment options as well as including useful patient resources and websites. It has never been more important for patients to be actively involved in their care. Being well informed helps you to make the best decisions together with your doctor.

Side effects of topical atropine 0.05% compared to 0.01% for myopia control in German school children: a pilot study.

PURPOSE: Based on findings of the Asian low-concentration atropine for myopia progression study, a concentration of 0.05% has been proposed as a good compromise between safety and efficacy for myopia control. However, no data on side effects have been published so far in Caucasian children receiving this dose. METHODS: Prior to commencement of bilateral atropine treatment with 0.05% atropine, 19 myopic children aged 5 to 15 years were treated in only one eye at bedtime leaving the other eye as a control. Pupil size, accommodation amplitude and near visual acuity were measured at 10:00 a.m. the next day and compared to the untreated contralateral control eye. The results were then compared to a cohort of 18 children whose treatment with 0.01% atropine commenced in a similar fashion. RESULTS: Twelve children (63%) reported visual impairment or reading difficulties. Anisocoria was 2.9 ± 1.1 mm. In comparison, 0.01% atropine led to a significantly less anisocoria of 0.8 ± 0.7 mm (p < 0.0001). Accommodation was decreased by - 4.2 ± 3.8 D in 0.05% atropine treated eyes, whereas 0.01% atropine induced hypoaccommodation of - 0.05 ± 2.5 D (p < 0.01). Near visual acuity was not significantly reduced in eyes treated with 0.05% atropine compared to 0.01% atropine (p = 0.26). CONCLUSION: Compared to 0.01%, our data indicate stronger more relevant side effects of 0.05% topical atropine in young Caucasian children with progressive myopia as recently reported in Asian children, potentially compromising acceptance and compliance.

Risk factors for an infection with Coxiella burnetii in German sheep flocks.

In Germany, sheep are the main source of human Q fever epidemics, but data on Coxiella burnetii (C. burnetii) infections and related risk factors in the German sheep population remain scarce. In this cross-sectional study, a standardised interview was conducted across 71 exclusively sheep as well as mixed (sheep and goat) farms to identify animal and herd level risk factors associated with the detection of C. burnetii antibodies or pathogen-specific gene fragments via univariable and multivariable logistic regression analysis. Serum samples and genital swabs from adult males and females of 3367 small ruminants from 71 farms were collected and analysed using ELISA and qPCR, respectively. On animal level, univariable analysis identified young animals (<2 years of age; odds ratio (OR) 0.33; 95% confidence interval (CI) 0.13-0.83) to reduce the risk for seropositivity significantly (p < 0.05). The final multivariable logistic models identified lambing all year-round (OR 3.46/3.65; 95% CI 0.80-15.06/0.41-32.06) and purchases of sheep and goats (OR 13.61/22.99; 95% CI 2.86-64.64/2.21-239.42) as risk factors on herd level for C. burnetii infection detected via ELISA and qPCR, respectively.

Prevalence of Coxiella burnetii in German sheep flocks and evaluation of a novel approach to detect an infection via preputial swabs at herd-level.

A prevalence study was conducted on German sheep flocks including goats if they cohabitated with sheep. In addition, a novel approach was applied to identify an infection at the herd-level before lambing season with preputial swabs, suspecting venereal transmission and ensuing colonisation of preputial mucosa with Coxiella (C.) burnetii. Blood samples and genital swabs were collected from breeding males and females after the mating season and were analysed by enzyme-linked immunosorbent assay (ELISA) and quantitative polymerase chain reaction (qPCR) respectively. In total, 3367 animals were sampled across 71 flocks. The true herd-level prevalence adjusted for misclassification probabilities of the applied diagnostic tests using the Rogan-Gladen estimator for the prevalence estimate and a formula by Lang and Reiczigel (2014) for the confidence limits, ranged between 31.3% and 33% (95% confidence interval [95% CI] 17.3-45.5) detected by the ELISA and/or qPCR. Overall 26-36.6% (95% CI 13-56.8) were detected by ELISA, 13.9% (95% CI 4.5-23.2) by the qPCR and 7.9-11.2% (95% CI 0.08-22.3) by both tests simultaneously. The range of results is due to data obtained from literature with different specifications for test quality for ELISA. Among eight farms with females shedding C. burnetii, three farms (37.5%) could also be identified by preputial swabs from breeding sires. This indicates less reliability of preputial swabs if used as a single diagnostic tool to detect C. burnetii infection at the herd-level.

Comparison of sporadic and familial behavioral variant frontotemporal dementia (FTD) in a North American cohort.

INTRODUCTION: Behavioral variant frontotemporal dementia (bvFTD) may present sporadically or due to an autosomal dominant mutation. Characterization of both forms will improve understanding of the generalizability of assessments and treatments. METHODS: A total of 135 sporadic (s-bvFTD; mean age 63.3 years; 34% female) and 99 familial (f-bvFTD; mean age 59.9; 48% female) bvFTD participants were identified. f-bvFTD cases included 43 with known or presumed chromosome 9 open reading frame 72 (C9orf72) gene expansions, 28 with known or presumed microtubule-associated protein tau (MAPT) mutations, 14 with known progranulin (GRN) mutations, and 14 with a strong family history of FTD but no identified mutation. RESULTS: Participants with f-bvFTD were younger and had earlier age at onset. s-bvFTD had higher total Neuropsychiatric Inventory Questionnaire (NPI-Q) scores due to more frequent endorsement of depression and irritability. DISCUSSION: f-bvFTD and s-bvFTD cases are clinically similar, suggesting the generalizability of novel biomarkers, therapies, and clinical tools developed in either form to the other.

Active lifestyles moderate clinical outcomes in autosomal dominant frontotemporal degeneration.

INTRODUCTION: Leisure activities impact brain aging and may be prevention targets. We characterized how physical and cognitive activities relate to brain health for the first time in autosomal dominant frontotemporal lobar degeneration (FTLD). METHODS: A total of 105 mutation carriers (C9orf72/MAPT/GRN) and 69 non-carriers reported current physical and cognitive activities at baseline, and completed longitudinal neurobehavioral assessments and brain magnetic resonance imaging (MRI) scans. RESULTS: Greater physical and cognitive activities were each associated with an estimated >55% slower clinical decline per year among dominant gene carriers. There was also an interaction between leisure activities and frontotemporal atrophy on cognition in mutation carriers. High-activity carriers with frontotemporal atrophy (-1 standard deviation/year) demonstrated >two-fold better cognitive performances per year compared to their less active peers with comparable atrophy rates. DISCUSSION: Active lifestyles were associated with less functional decline and moderated brain-to-behavior relationships longitudinally. More active carriers "outperformed" brain volume, commensurate with a cognitive reserve hypothesis. Lifestyle may confer clinical resilience, even in autosomal dominant FTLD.

Swept-source optical coherence tomography angiography alleviates shadowing artifacts caused by subretinal fluid.

PURPOSE: To characterize the choriocapillaris (CC) structure in relation to subretinal fluid (SRF) as a possible systematic error source using spectral domain (SD-OCTA) compared to swept-source optical coherence tomography angiography (SS-OCTA). METHODS: This is a prospective case-control study of 23 eyes. Ten patients with acute central serous chorioretinopathy (CSC), three patients with partial macular-off retinal detachment (RD) and ten healthy, age-matched controls were included. Abnormal CC decorrelation signals were quantitatively compared in CSC and controls by means of custom image processing. To investigate the influence of SRF on CC OCTA signal, the extent of SRF was quantified with a macular heatmap and compared with the corresponding OCTA signal of the CC. RESULTS: SS-OCTA yielded a more homogeneous OCTA signal from the CC than SD-OCTA, offering less signal dispersion and variability in healthy and diseased eyes. Both devices demonstrated CC signal voids in CSC and RD, respectively. In CCS, the voids were predominantly located in the area with SRF. Compared to SD-OCTA, SS-OCTA delivered a more homogenous OCTA signal and reduced signal voids in the CC underneath SRF in both RD and CSC (CSC, 7.6% ± 6.3% vs, 19.7% ± 9.6%, p < 0.01). Despite this significant attenuation of signal voids, SS-OCTA continued to reveal signal voids below SRF and more pixels with reduced OCTA signals in CSC patients compared to controls (7.6% ± 6.3%, 0.1% ± 0.1%, p < 0.0001). CONCLUSION: Understanding OCTA artifacts is critical to ensure accurate clinical evaluations. In this study, we describe the presence of SRF as an important shadow-causing artifact source for CC OCTA analysis which can be mitigated but not completely eliminated by employing SS-OCTA.

All-fiber holmium distributed feedback laser at 2.07 µm.

In this Letter, we present the results on fabrication and investigation of a holmium (Ho) distributed fiber laser based on a π-phase-shifted FBG inscribed in a heavily Ho-doped fiber by IR femtosecond laser pulses. Single-polarization and single-transverse mode operation regimes were observed with a linewidth of the order of 10 kHz and output power up to 53 mW at 2.07 µm. Lasing regimes are compared for room and cryogenic (77 K) temperatures of the laser cavity. To the best of our knowledge, this is the first realization of such type of fiber laser based on holmium active medium.

Random Raman fiber laser based on a twin-core fiber with FBGs inscribed by femtosecond radiation.

Narrowband Raman lasing in a polarization-maintaining two-core fiber (TCF) is demonstrated. Femtosecond point-by-point inscription of fiber Bragg gratings (FBGs) in individual cores produces a half-open cavity with random distributed feedback. The laser linewidth in the cavity with a single FBG inscribed in one core of the TCF reduced by ∼2 times with respect to the cavity with a fiber loop mirror. It is shown that the inscription of two FBGs in different cores leads to the formation of a Michelson-type interferometer, leading to the modulation of generation spectra near threshold. This technique offers new possibilities for spectral filtering or multi-wavelength generation.