Polymer Backbone Chemistry Shapes the Alkaline Stability of Metallopolymer Anion-Exchange Membranes

Anion-exchange membrane fuel cells and water electrolyzers have garnered significant attention in past years due to their potential role in sustainable and affordable energy conversion and storage. However, the chemical stability of the polymeric anion-exchange membranes (AEMs), the key component in these devices, currently limits their lifespan. Recently, metallopolymers have been proposed as chemically stable alternatives to organic cations, using metal centers as ion transporters. In metallopolymer AEMs, various properties such as alkaline stability, water uptake, flexibility, and performance, are determined by both the metal complex and polymer backbone. Herein we present a systematic study investigating the influence of the polymer backbone chemistry on some of these properties, focusing on the alkaline stability of low-oxophilicity gold metallopolymers. Despite the use of a common N-heterocyclic carbene ligand, upon gold metalation using the same reaction conditions, different polymer backbones end up forming different gold complexes. These findings suggest that polymer chemistry affects the metalation reaction in addition to the other properties relevant to AEM performance.

Early Release Science of the exoplanet WASP-39b with JWST NIRSpec PRISM

Transmission spectroscopy1-3 of exoplanets has revealed signatures of water vapour, aerosols and alkali metals in a few dozen exoplanet atmospheres4,5. However, these previous inferences with the Hubble and Spitzer Space Telescopes were hindered by the observations' relatively narrow wavelength range and spectral resolving power, which precluded the unambiguous identification of other chemical species-in particular the primary carbon-bearing molecules6,7. Here we report a broad-wavelength 0.5-5.5 µm atmospheric transmission spectrum of WASP-39b8, a 1,200 K, roughly Saturn-mass, Jupiter-radius exoplanet, measured with the JWST NIRSpec's PRISM mode9 as part of the JWST Transiting Exoplanet Community Early Release Science Team Program10-12. We robustly detect several chemical species at high significance, including Na (19σ), H2O (33σ), CO2 (28σ) and CO (7σ). The non-detection of CH4, combined with a strong CO2 feature, favours atmospheric models with a super-solar atmospheric metallicity. An unanticipated absorption feature at 4 µm is best explained by SO2 (2.7σ), which could be a tracer of atmospheric photochemistry. These observations demonstrate JWST's sensitivity to a rich diversity of exoplanet compositions and chemical processes.

Subretinal Hyperreflective Material (SHRM) as biomarker of activity in Exudative and Non- exudative inflammatory choroidal neovascularization

AIM

To analyze the structural features and therapeutic response in clinical and subclinical inflammatory choroidal neovascularization (i-CNV) detected inside subretinal hyperreflective material (SHRM) using swept-source optical coherence tomography (SS-OCT) and SS-OCT angiography (SS-OCTA).

METHODS

In this prospective interventional study, subjects with quiescent posterior uveitis presenting with SHRM on SS-OCT and CNV network on SS-OCTA were included. Subjects with intraretinal fluid/subretinal fluid (IRF/SRF) received intravitreal antivascular endothelial growth factor (anti-VEGF) injections, while those with no IRF/SRF either received treatment or observation for 6 months until they developed IRF/SRF or decrease in best-corrected visual acuity (BCVA)/metamorphopsia. Serial comparisons included SHRM width and height and intrinsic flow signal on OCTA.

RESULTS

28 eyes of 22 subjects (12 males; mean age: 29.52 ± 12.56 years) were evaluated. Subjects with IRF/SRF at baseline (n = 6 eyes; termed as exudative iCNVs) receiving treatment showed significant improvement in BCVA (p = .017), SHRM width/height and flow signal (p < .05). Among eyes with no IRF/SRF (n = 22; termed as non-exudative iCNVs), 7 received treatment and showed significant improvement in SHRM parameters and BCVA (p < .05). 4/15(26.67%) eyes that received no treatment developed IRF/SRF upon 6-month follow-up.

CONCLUSION

SHRM may act as a useful biomarker to monitor activity and response to therapy in eyes with iCNV.

Choriocapillaris Flow Deficit in Tubercular Serpiginous-Like Choroiditis with and without Paradoxical Worsening

PURPOSE

The aim is to analyze automated quantification of choriocapillaris flow deficit (CCFD) on swept-source (SS)-optical coherence tomography angiography (OCTA) in tubercular serpiginous-like choroiditis (TBSLC).

METHODS

In this prospective study, automated CCFD calculations were performed on SS-OCTA and compared with CCFD areas on indocyanine green angiography (ICGA). Patients were divided into two groups based on the occurrence of paradoxical worsening (PW).

RESULTS

Twenty-nine eyes (29 subjects; 18 males; mean age: 33±12 years) were included. The mean CCFD at baseline was 34.9 ± 4.3% on OCTA in eyes without PW and 35.4 ± 5.0% on SS-OCTA with PW (p = .77). At 4 and 12 weeks, CCFD on SS-OCTA improved to 30.6 ± 3.9% and 28.0 ± 4.2% (p < .001) without PW, respectively, and increased to 42.9 ± 4.4% and 48.8 ± 4.1% (p < .001) with PW, respectively. The SS-OCTA CCFD correlated well with ICGA (r = 0.48; p < .001).

CONCLUSIONS

Automated quantitative serial assessment of CCFD on SS-OCTA can serve as a useful biomarker of disease activity in eyes with TBSLC.

YELLOW SUBRETINAL PIGMENT EPITHELIUM DEPOSITS: A NOVEL SIGN IN OCULAR TUBERCULOSIS

PURPOSE

To describe a novel clinical and imaging finding in patients with tubercular posterior uveitis.

METHODS

A retrospective review of 3 cases presented at a tertiary referral eye centre in North India was performed between June 2016 and March 2019. All the patients had received an initial diagnosis of noninfective etiologies (sympathetic ophthalmia, necrotizing scleritis, and lymphoma). Fundus photography, fluorescein angiography, fundus autofluorescence, and enhanced-depth imaging optical coherence tomography were reviewed.

RESULTS

Three patients (all Asian Indian women: aged 18, 49, and 52 years) diagnosed with panuveitis were investigated for various etiologies based on the initial clinical suspicion. During the course of therapy, all the patients developed peripheral yellow subretinal pigment epithelium deposits (YSRPE) which appeared hypoautofluorescent on fundus autofluorescence and initially hypofluorescent with late hyperfluorescence on fluorescein angiography. The patients were subjected to detailed systemic evaluation and laboratory tests. All the patients showed acid-fast bacilli on invasive tissue biopsies. After initiation of antitubercular therapy, the lesions resolved in all eyes.

CONCLUSION

Yellow subretinal pigment epithelium deposits represent a novel and important diagnostic sign of tubercular posterior uveitis.

Effect of Twin Block Therapy Versus Fixed Functional Appliances on Pharyngeal Airway Space in Skeletal Class II Patients: A Prospective Cephalometric Study

BACKGROUND

Class II malocclusion is one of the most common malocclusion with varied prevalence. Functional therapy with appliances like Twin Block or Fixed functional appliances forms the mainstay of treatment in growing Class II patients. These patients might demonstrate narrow airway due to the retrognathic position of the mandible. This study investigated the effects of twin block and fixed functional appliance therapy (Forsus™ FRD) on the pharyngeal airway space in skeletal Class II patients.

METHODS

Forty patients with Class II malocclusion were selected and divided into two equal groups of 20 patients each for both Twin block and Forsus group. Lateral cephalograms were obtained before and after the functional appliance therapy. Evaluation was done for changes in hyoid bone position, pharyngeal airway dimensions and tongue position.

RESULTS

The variables of the study showed better hyoid position in both the groups. In Twin Block group, an increase in hy-apw2 and hy-PoFH suggested anterior positioning of hyoid and a decrease in H-MP and hy-ML indicated superior positioning. In Forsus group an increase in H-H', hy-FH, hy-ML, hy-NL, hy-NSL and hy-OL suggested inferior positioning of hyoid, while an increase in hy-apw2, hy-CVT, hy-PoFH, hy-RL and hy'-tgo indicated anterior positioning of hyoid bone after functional therapy.

CONCLUSION

Both the twin block and Forsus™ FRD improved the position of the hyoid bone after the functional appliance therapy however the changes were not statistically significant. Twin block and Forsus™ had similar effect on the hyoid bone position, pharyngeal dimensions and the tongue position.

Preidentification of high-risk pregnancies to improve triaging at the time of admission and management of complications in labour room: a quality improvement initiative

Complications can occur anytime during pregnancy and childbirth. Pregnancies associated with high-risk factors have a higher-than-normal risk for fetomaternal complications. Bhagwan Mahavir hospital is a public sector hospital catering to low-risk and high-risk pregnant women (PW) in the labour room (LR)). The obstetrics and gynaecology team observed that at times the LR team failed to identify high-risk pregnancy (HRP) during admission in LR and to manage complications timely and efficiently. Therefore, the team started a quality improvement (QI) project in January 2019 with the aim to admit preidentified HRP in LR from existing 0% to 80% in 3 months.

The QI team followed the point-of-care quality improvement methodology to conduct this improvement process. They identified HRP in the outpatient department (OPD) during their antenatal care (ANC) visits, mentioned an HRP number on their ANC cards, and did risk stratification with yellow and red stickers into moderate and severe HRP respectively. Preidentified HRP were attended, admitted and managed on priority in the LR. The team achieved its aim in the ninth week of the QI initiative and sustaining to date. The team also measured and analysed the type of HRP identified in OPD, complications occurring around the process of childbirth in LR, maternal near-miss, maternal death and PW referred out from LR. They observed a 6.5%-point reduction (68.93%) in the median complication rate of major life-threatening complications following this improvement process.

This new intervention facilitated the team in early initiation of management of HRP in OPD, their triaging in LR, preparedness towards managing complications, involvement of support staff, PW and their relatives in the patient care, and redistribution of human resources according to priority area. The lessons learnt are generalisable and can be used in other facilities with similar settings.

A repeating fast radio burst associated with a persistent radio source

The dispersive sweep of fast radio bursts (FRBs) has been used to probe the ionized baryon content of the intergalactic medium1, which is assumed to dominate the total extragalactic dispersion. Although the host-galaxy contributions to the dispersion measure appear to be small for most FRBs2, in at least one case there is evidence for an extreme magneto-ionic local environment3,4 and a compact persistent radio source5. Here we report the detection and localization of the repeating FRB 20190520B, which is co-located with a compact, persistent radio source and associated with a dwarf host galaxy of high specific-star-formation rate at a redshift of 0.241 ± 0.001. The estimated host-galaxy dispersion measure of approximately [Formula: see text] parsecs per cubic centimetre, which is nearly an order of magnitude higher than the average of FRB host galaxies2,6, far exceeds the dispersion-measure contribution of the intergalactic medium. Caution is thus warranted in inferring redshifts for FRBs without accurate host-galaxy identifications.

RETINAL PIGMENT EPITHELIAL IRREGULARITY AND ATROPHY AFTER INTERNAL MEMBRANE PEELING: A REPORT OF TWO CASES

PURPOSE

To report two cases of widespread retinal pigment epithelial clumping, irregularity, and atrophy after uncomplicated 25-gauge pars plana vitrectomy with brilliant blue-green-assisted internal limiting membrane peeling.

METHODS

Retrospective analysis of 2 eyes of 2 patients who underwent 25-gauge pars plana vitrectomy for macular diseases (macular hole with retinal detachment and vitreomacular traction) was performed. Surgical notes and video recordings were reviewed to determine the surgical procedures performed and the duration of the surgery. Multimodal imaging analysis, including fundus photography, fundus autofluorescence imaging, and optical coherence tomography were performed to determine the pathological changes in the postoperative period.

RESULTS

The mean age of the patients (all females) was 78 years. In all the patients, brilliant blue-green-assisted internal limiting membrane peeling was performed without any intraoperative complications. Four weeks after an uncomplicated surgery, the patients complained of progressive central visual disturbance and metamorphopsia. Retinal imaging demonstrated retinal pigment epithelial clumps and irregularity, which appeared as hyperautofluorescent on fundus autofluorescence, and widespread retinal pigment epithelial atrophy (hypoautofluorescent on fundus autofluorescence) in the posterior pole and peripapillary region, along with retinal and choroidal thinning.

CONCLUSION

In uncomplicated vitrectomy consisting of brilliant blue-green-assisted internal limiting membrane peeling, a remote risk of widespread retinal pigment epithelial damage exists even with the use of modern endoilluminators and relatively short surgical duration. Retinal phototoxicity seems to be the primary cause; however, dye-related cytotoxicity or a combination of both cannot be ruled out.

The use of optical coherence tomography angiography in comparing choriocapillaris recovery between two treatment strategies for multifocal choroiditis: a pilot clinical trial

PURPOSE

To compare differences in choriocapillaris flow deficit (CC FD) in multifocal choroiditis (MFC) between two treatment arms using optical coherence tomography angiography (OCTA).

METHODS

In this prospective randomized clinical trial, patients were randomized to either Group 1 which received standard tapering dose of oral corticosteroids, or Group 2 which received additional dexamethasone implant (or intravitreal methotrexate). The patients were followed-up until 12 weeks using OCTA and other imaging tools. CC FD and visual acuity between the two groups were compared at each visit.

RESULTS

Twenty-five subjects (17 males; 25 eyes) were studied (11 eyes in Group 1). There were no differences between the visual acuity or CC FD (1.12 versus 1.08 mm²; p = 0.86) at baseline between the groups. However, patients in Group 2 achieved better visual acuity (0.32 ± 0.23 versus 0.15 ± 0.11; p = 0.025) and CC FD (0.54 versus 0.15 mm²; p = 0.008) at 12 weeks.

CONCLUSIONS

OCTA is a useful tool in monitoring the CC FD recovery after treatment in MFC. Patients receiving intravitreal corticosteroid/methotrexate in addition to systemic corticosteroid showed greater resolution of CC FD on OCTA compared to those receiving only oral corticosteroids.

A repeating fast radio burst source in a globular cluster

Fast radio bursts (FRBs) are flashes of unknown physical origin¹. The majority of FRBs have been seen only once, although some are known to generate multiple flashes^2,3. Many models invoke magnetically powered neutron stars (magnetars) as the source of the emission^4,5. Recently, the discovery⁶ of another repeater (FRB 20200120E) was announced, in the direction of the nearby galaxy M81, with four potential counterparts at other wavelengths⁶. Here we report observations that localized the FRB to a globular cluster associated with M81, where it is 2 parsecs away from the optical centre of the cluster. Globular clusters host old stellar populations, challenging FRB models that invoke young magnetars formed in a core-collapse supernova. We propose instead that FRB 20200120E originates from a highly magnetized neutron star formed either through the accretion-induced collapse of a white dwarf, or the merger of compact stars in a binary system⁷. Compact binaries are efficiently formed inside globular clusters, so a model invoking them could also be responsible for the observed bursts.

Isoindolinium Groups as Stable Anion Conductors for Anion-Exchange Membrane Fuel Cells and Electrolyzers

Anion-exchange membrane (AEM) fuel cells (AEMFCs) and water electrolyzers (AEMWEs) have gained strong attention of the scientific community as an alternative to expensive mainstream fuel cell and electrolysis technologies. However, in the high pH environment of the AEMFCs and AEMWEs, especially at low hydration levels, the molecular structure of most anion-conducting polymers breaks down because of the strong reactivity of the hydroxide anions with the quaternary ammonium (QA) cation functional groups that are commonly used in the AEMs and ionomers. Therefore, new highly stable QAs are needed to withstand the strong alkaline environment of these electrochemical devices. In this study, a series of isoindolinium salts with different substituents is prepared and investigated for their stability under dry alkaline conditions. We show that by modifying isoindolinium salts, steric effects could be added to change the degradation kinetics and impart significant improvement in the alkaline stability, reaching an order of magnitude improvement when all the aromatic positions are substituted. Density functional theory (DFT) calculations are provided in support of the high kinetic stability found in these substituted isoindolinium salts. This is the first time that this class of QAs has been investigated. We believe that these novel isoindolinium groups can be a good alternative in the chemical design of AEMs to overcome material stability challenges in advanced electrochemical systems.

Effect of anxiety and psychologic stress on periodontal health: a systematic review and meta-analysis

OBJECTIVE

The primary objective of this meta-analysis (PROSPERO No: CRD42019124695) was to assess the association between psychologic stress, anxiety, and periodontitis.

DATA SOURCES

The electronic search was conducted using PubMed, Embase, and Scopus, by three independent reviewers till December 2019. The search was limited to human studies published only in English language. The fixed-effect model and random-effects model were used to obtain the overall mean difference, odds ratio (OR), and its 95% CI for all studies. The heterogeneity was calculated by I2 statistics. The Newcastle--Ottawa scale was used to assess the risk of bias in the included studies. Out of 775 potentially relevant articles, 25 studies were selected for systematic review and only 14 studies could be used for meta-analysis in three subsets. The pooled OR for stress and periodontitis was 1.78, which was statistically highly significant (I2 = 98.6%, P = .00). Mean salivary cortisol levels as a measure of stress in patients with periodontitis was 4.81 nmol/L (I2 = 98.0%, P = .08). State-Trait Anxiety Inventory value was seen as -1.28 (I2 = 0.0%, P = .06) for state anxiety and -0.11 (I2 = 0.0%, P = .85) for trait anxiety in patients with periodontitis.

CONCLUSION

The findings indicate a role of psychologic stress and anxiety in the progression of periodontitis.

Effect of nano-crystalline silver membrane on early wound healing after periodontal surgery: A comparative randomized study

Background:

Periodontal dressings are used for wound protection and patient comfort. Nano-silver particles have the ability to promote wound healing through anti-inflammatory properties. Hence, the present study aims to evaluate early wound healing parameters following periodontal surgery using nano-crystalline silver membrane as periodontal dressing.

Materials and Methods:

Forty-two systemically healthy patients diagnosed with chronic periodontitis indicated for periodontal flap surgery were enrolled for the present study. Post surgery, the patients were randomly allocated to either a nano-crystalline silver dressing (Acticoat™) group (test group) or only the noneugenol dressing group (control group). Plaque index (PI) and wound healing index were recorded at the 7^th- and 14^th-day postsurgery. The microbiological analysis and vascular endothelial growth factor (VEGF) levels were evaluated at baseline and 7^th-day postsurgery.

Results:

The healing index was significantly higher in the test group as compared to the control group at days 7 and 14 (P < 0.001; P < 0.001). The colony-forming units/ml count of bacteria were significantly reduced postsurgery in the test group (P = 0.019). VEGF levels increased significantly 7^th-day postsurgery in the test group (P = 0.001). There was no statistically significant difference in the PI on the 7^th-day postsurgery between the two groups (P = 0.173).

Conclusion:

The results of the study revealed that silver can be used as a potent periodontal dressing ingredient that can decrease the microbial colonization beneath the pack and promote faster healing postsurgery due to its antimicrobial activity.

Alkaline Stability of Low Oxophilicity Metallopolymer Anion-Exchange Membranes

Anion-exchange membrane fuel cells (AEMFCs) are promising energy conversion devices due to their high efficiency and relatively low cost. Nonetheless, AEMFC operation time is currently limited by the low chemical stability of their polymeric anion-exchange membranes. In recent years, metallopolymers, where the metal centers assume the ion transport function, have been proposed as a chemically stable alternative. Here we present a systematic study using a polymer backbone with side-chain N-heterocyclic carbene (NHC) ligands complexed to various metals with low oxophilicity, such as copper, zinc, nickel, and gold. The golden metallopolymer, using the metal with the lowest oxophilicity, demonstrates exceptional alkaline stability, far superior to state-of-the-art quaternary ammonium cations, as well as good in-situ AEMFC results. These results demonstrate that judiciously designed metallopolymers may be superior to purely organic membranes and provides a scientific base for further developments in the field.

Sleep quality mediates the relationship between risk of obstructive sleep apnea and acute stress in young adults

Intermittent hypoxia and transient arousals in obstructive sleep apnea (OSA) can lead to poor sleep quality and acute stress. Rising levels of obesity and increased incidence of OSA in young adults predisposes them to acute stress. We propose a mediation model to assess if risk of OSA is associated with acute stress and if the relationship between risk for OSA and acute stress is mediated by sleep quality. 493 healthy individuals (F = 237, M = 256) from 18 - 25 years of age (mean age 20.3 ± 1.53 years) were screened for OSA, sleep quality and acute stress using STOP-BANG questionnaire, Pittsburg Sleep Quality Index and American Psychiatry Association's National Stressful Events Survey Acute Stress Disorder Short Scale (NSESS-S), respectively. 73 participants (17.3%) were found at an intermediate and high risk of OSA by STOP BANG questionnaire. 79 (16%) participants reported level of stress as 'None'. Mild, moderate and severe stress was present in 248 (50.3%), 109 (22.1%), 51 (10.3%) and 16 (3.2%) participants, respectively. The odds of having severe and extreme stress among those at risk of sleep apnea is 2.18 times higher than that among those not at risk of sleep apnea (OR: 2.18, 95%, confidence interval: 1.37-3.51). Sobel test established that the relationship between OSA and acute stress is mediated by sleep quality. Sleep quality mediates the relationship between risk for sleep apnea and acute stress. This highlights the importance of screening for OSA in young adults, particularly young men with high BMI, presenting with high stress levels.

Antiviral Therapy for Varicella Zoster Virus (VZV) and Herpes Simplex Virus (HSV)-Induced Anterior Uveitis: A Systematic Review and Meta-Analysis

Topic: Herpes simplex virus (HSV) and varicella zoster virus (VZV) are the most common ocular pathogens associated with infectious anterior uveitis. Currently, there are a number of antiviral agents administered to treat viral anterior uveitis (VAU). However, there is no consensus or guidelines about the most appropriate approach leading for the best treatment outcomes with fewer ocular complications. Clinical Relevance: To perform a systematic review and meta-analysis of the efficacy of different antiviral therapies in the management of anterior uveitis secondary to HSV and VZV. Methods: We searched PubMed, Web of Science, CINAHL, OVID, and Embase up to January 2020. Randomized trials, non-randomized intervention studies, controlled before and after studies and observational studies assessing the effect of oral and or topical treatments for VAU were considered. Data extraction and analysis with evaluation of the risk of bias in the included trials were performed. Results: Oral acyclovir demonstrated a statistically significant good treatment outcome in the management of VZV anterior uveitis (vs. placebo) (OR 0.26, 95% CI 0.11-0.59), but did not have similar effect in HSV anterior uveitis (OR 0.47, 95% CI 0.15-1.50). In the treatment of VZV anterior uveitis, there was significant superiority of oral acyclovir-7 day course-over topical acyclovir (OR 4.17, 95% CI 1.28-13.52). Whereas, there was no significant superiority of one of the following treatment regimens over the others: topical acyclovir over topical corticosteroids (OR 1.86, 95% CI 0.67-5.17), and oral acyclovir-7 day course-over oral acyclovir-14 day course-(OR 0.21, 95% CI 0.01-4.50) or oral valaciclovir (OR 1.40, 95% CI 0.48-4.07). Conclusion: Treatment of HSV and VZV anterior uveitis is currently based on individual experiences and limited literature, largely due to weak clinical trial evidence in this regard. Our results highlight the existence of a substantial gap in our evidence base. This finding might contribute to future research studies to ascertain the role of different antiviral therapies in the treatment of VAU. Systematic Review Registration: PROSPERO registration number: CRD420202 00404.

Ligand Valency Effects on the Alkaline Stability of Metallopolymer Anion-Exchange Membranes

Long-term stability is a key requirement for anion-exchange membranes (AEMs) for alkaline fuel cells and electrolyzers that is yet to be fulfilled. Different cationic chemistries are being exploited to reach such a goal, and metallopolymers present the unique advantage of chemical stability towards strong nucleophiles as compared to organic cations. Yet, the few metallopolymers tested in strongly alkaline conditions or even in fuel cells still degrade. Therefore, fundamental studies can be advantageous in directing future developments towards this goal. Here, a systematic study of the effect of ligand valency is presented, using nickel-based metallopolymers on polynorbornene backbones, functionalized with multidentate pyridine ligands. Metallopolymers using a single ligand type as well as all the possible mixtures are prepared and their relative stability towards aggressive alkaline conditions compared. Metallopolymer in which nickel ions are hexacoordinated with two tridentate ligands demonstrates superior stability. More importantly, by comparing all the metallopolymers' stability, the reason behind such relative stability provides design parameters for novel metallopolymer AEMs.

Clinical and Multimodal Imaging Clues in Differentiating Between Tuberculomas and Sarcoid Choroidal Granulomas

PURPOSE

To compare the differences among clinical, demographic, and multimodal imaging features of choroidal granulomas associated with tuberculosis and sarcoidosis.

DESIGN

Retrospective comparative case series.

METHODS

Clinical features and fundus imaging, including fluorescein and indocyanine green angiography and optical coherence tomography of patients with tuberculomas and sarcoid choroidal granulomas seen at 3 tertiary care centers, were reviewed. The differences among clinical appearances, including morphology of the lesions (size, shape, extent), vascularity, and multimodal imaging features, were compared. Repeated logistic regression measurements with a multilevel random effects model was used to assess characteristics of individual granulomas that could predict the underlying cause.

RESULTS

The study included 47 eyes of 38 patients (22 with tuberculomas and 16 with sarcoid granulomas; total of 138 granulomas). Patients with tuberculomas were significantly younger (33.8 ± 10.1 vs. 48.6 ± 14.3 years, respectively; P = .002), but no sex differences were observed. In comparison with sarcoid granulomas, tuberculomas were solitary (P <.001), intense yellow, lobulated, full thickness, and located in the perivascular region (all P <.001); they were also larger (16.01 ± 9.7 mm² vs. 2.7 ± 4.5 mm², respectively; P <.001) and were vascularized (P <.001). Sarcoid granulomas were associated with retinal vasculitis (P = .003) and disc hyperfluorescence (P <.001). Logistic regression showed that multiple granulomas were associated with sarcoidosis (odds ratio [OR]: 3.5; 95% confidence interval: 1.8-6.9; P <.001). Granulomas larger than 6.45 mm² had the highest area under the receiver operating curves (0.94) for differentiating tuberculomas from sarcoid granulomas.

CONCLUSIONS

Tuberculomas and sarcoid choroidal granulomas have various clinical and imaging features that help differentiate between the 2 entities with high predictability and can supplement immunological and radiological tests in a diagnosis.

LINEZOLID-INDUCED MITOCHONDRIAL TOXICITY PRESENTING AS RETINAL NERVE FIBER LAYER MICROCYSTS AND OPTIC AND PERIPHERAL NEUROPATHY IN A PATIENT WITH CHRONIC GRANULOMATOUS DISEASE

PURPOSE

To report a case with unique changes in the retinal nerve fiber layer observed on optical coherence tomography in a 22-year-old patient on chronic linezolid therapy for recurrent pyogenic liver abscesses with underlying chronic granulomatous disease.

METHODS

History and clinical examination, laboratory evaluation, fluorescein angiography, and optical coherence tomography.

RESULTS

The patient presented with best-corrected visual acuity of 20/200 in the right eye and 20/125 in the left eye. He had moderate optic disk edema and superotemporal field defects bilaterally. Swept-source optical coherence tomography revealed the presence of retinal nerve fiber layer microcystic spaces. Laboratory tests showed no positive findings except for an elevated lactic acid level. Linezolid-induced optic neuropathy was suspected, and the drug was discontinued. Six weeks after termination of oral linezolid therapy, the optic disk edema and the microcystic spaces in the retinal nerve fiber layer resolved, and the best-corrected visual acuity improved to 20/50 in the right and 20/40 in the left eye, respectively.

CONCLUSION

Linezolid is a widely used antibiotic with broad-spectrum action. However, chronic use can lead to mitochondrial toxicity that may have protean manifestations. Ocular examination, particularly of the optic nerve and nerve fiber layer using multimodal imaging, is critical in diagnosing such toxicity.

Recent advances in wide field and ultrawide field optical coherence tomography angiography in retinochoroidal pathologies

Introduction: With the advent of wide field (WF) and ultra-wide field (UWF) imaging in color fundus photography and fluorescein angiography (FA), the importance of an expanded field-of-view (FOV) has been illustrated for early detection of several chorioretinal disorders. The need to bring similar utility to optical coherence tomography angiography (OCTA) is imperative.Areas covered: For this review, we explored all research items with WF or UWF on Pubmed Central and Google Scholar. Software-based methods included algorithms for motion correction, artifact reduction, image pre-processing, post-processing and montage protocols while hardware methods included swept-source OCTA, faster scanning sources, hardware-based motion tracking and image registration, scanning sources with faster speeds and lower resolution. For various disorders such as diabetic retinopathy, uveitis, vascular disorders, among others, the increased FOV showed demonstrably increased detection rates and diagnostic yield.Expert opinion: Increased FOV in OCTA imaging is a meaningful and impactful step in ophthalmic imaging. Overcoming the hardware-based limitations can potentially yield higher FOV without loss of important details. In addition to improvements in the hardware and available equipment, better software tools and image processing algorithms may greatly enhance the utility of UWF OCTA in care of patients with various retinochoroidal diseases.

Ocular surface manifestations of coronavirus disease 2019 (COVID-19): A systematic review and meta-analysis

Purpose

This study was performed to determine the occurrence of ocular surface manifestations in patients diagnosed with coronavirus disease 2019 (COVID-19) due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Methods

A systematic search of electronic databases i.e. PubMed, Web of Science, CINAHL, OVID and Google scholar was performed using a comprehensive search strategy. The searches were current through 31st May 2020. Pooled data from cross-sectional studies was used for meta-analysis and a narrative synthesis was conducted for studies where a meta-analysis was not feasible.

Results

A total of 16 studies reporting 2347 confirmed COVID-19 cases were included. Pooled data showed that 11.64% of COVID-19 patients had ocular surface manifestations. Ocular pain (31.2%), discharge (19.2%), redness (10.8%), and follicular conjunctivitis (7.7%) were the main features. 6.9% patients with ocular manifestations had severe pneumonia. Viral RNA was detected from the ocular specimens in 3.5% patients.

Conclusion

The most common reported ocular presentations of COVID-19 included ocular pain, redness, discharge, and follicular conjunctivitis. A small proportion of patients had viral RNA in their conjunctival/tear samples. The available studies show significant publication bias and heterogeneity. Prospective studies with methodical collection and data reporting are needed for evaluation of ocular involvement in COVID-19.

Subretinal Hemorrhage Complicating Retinal Angiomatous Proliferation in Tubercular Retinal Vasculitis

PURPOSE

To report a patient with submacular hemorrhage due to retinal angiomatous proliferation (RAP) in tubercular retinal vasculitis (TRV).

METHODS

Case report.

RESULTS

We report a 33-year-old Asian Indian patient of TRV presenting with capillary non-perfusion areas, submacular hemorrhage and venous loops. The patient presented with sudden onset decrease in vision in the right eye. Multimodal imaging revealed presence of retinal vascular anastomosis and stage 2 RAP. Systemic examination was within normal limits. Laboratory evaluation revealed positive Mantoux and interferon gamma release assay. He underwent right eye intravitreal injection of recombinant tissue plasminogen activator (12.5µg/0.1ml) with 100% sulphur hexafluoride (SF6) tamponade. The patient had successful displacement of the submacular hemorrhage with some improvement in visual acuity.

CONCLUSION

This case highlights that rare vascular alterations such as RAP can develop in subjects with ocular tuberculosis.

The Collaborative Ocular Tuberculosis Study (COTS)-1: A Multinational Descriptive Review of Tubercular Uveitis in Paediatric Population

PURPOSE

To examine disease profile of tubercular uveitis (TBU) in Paediatric population.

METHODS

Among 945 patients of the retrospective multinational study by the Collaborative Ocular Tuberculosis Study (COTS)-1, 29 Paediatric patients diagnosed with TBU were analyzed.

RESULTS

Mean age of disease presentation was 12.8 (range 4-18 years), with predominance of males (n = 14/20; 70.0%) and Asian ethnicity (n = 25/29; 86.2%). Posterior uveitis (n = 14/28; 50%) was the most frequent uveitis phenotype, with choroidal involvement occurring in 64.7% (n = 11/17). Incidence of optic disc edema and macular edema was higher in children (n = 8/18; 44.4% and n = 5/18; 27.8%, respectively) than in adults (n = 160/942; 16.9% and n = 135/942; 14.3%, respectively). Comparison of optic disc edema between subgroups showed a significant difference (P =.006). All patients received oral corticosteroids, most of them with antitubercular therapy. Treatment failure developed in 4.8% (n = 1/21).

CONCLUSIONS

Children have a more severe inflammatory response to the disease, and an intensive anti-inflammatory therapeutic regimen is required to achieve a positive treatment outcome.

The Collaborative Ocular Tuberculosis Study (COTS)-1: A Multinational Review of 165 Patients with Tubercular Anterior Uveitis

PURPOSE

The Collaborative Ocular Tuberculosis Study (COTS) Group sought to address the diagnostic uncertainty through retrospective cohort analysis of treatment regimens and therapeutic outcomes for patients with tubercular Anterior Uveitis (TAU) across international centers.

METHODS

Multicentre retrospective analysis of patients diagnosed with TAU between January 2004 to December 2014 that had a minimum follow-up of 1 year.

RESULTS

One hundred and sixty-five patients were included. One hundred and seven subjects received antitubercular therapy (ATT) (n = 107/165; 64.9%) with all the patients receiving topical steroid therapy. Treatment failure was noted in 17 patients (n = 17/165; 10.3%), more frequently described in patients that received ATT (n = 13/107, 12.2%), than those that did not receive ATT (n = 4/58, 6.9%).

CONCLUSION

In this retrospective study, addition of ATT did not have any statistically significant impact on outcome in patients with TAU.

Twenty-four Month Outcomes in the Collaborative Ocular Tuberculosis Study (COTS)-1: Defining the "Cure" in Ocular Tuberculosis

PURPOSE

To report the clinical findings, anatomical features, and treatment outcomes in subjects with ocular tuberculosis (OTB) at 24 months in the Collaborative Ocular Tuberculosis Study (COTS)-1.

METHODS

Of the 945 subjects included in COTS-1, those who completed a 24-month follow-up after completion of treatment were included. The main outcome measure was a number of patients with treatment failure (TF).

RESULTS

228 subjects (120 males; mean age of 42.82 ± 14.73 years) were included. Most common phenotype of uveitis was posterior (n = 81; 35.53%), and panuveitis (n = 76; 33.33%). Fifty-two patients (22.81%) had TF. On univariable analysis, odds of high TF was observed with bilaterality (OR: 3.46, p = .003), vitreous haze (OR: 2.14, p = .018), and use of immunosuppressive therapies (OR: 5.45, p = .003). However, only bilaterality was significant in the multiple regression model (OR: 2.84; p = .02).

CONCLUSIONS

Majority of subjects (>75%) achieved cure in the COTS-1 at 24-month follow-up. The concept of "cure" may be a valuable clinical endpoint in trials for OTB.

The Collaborative Ocular Tuberculosis Study (COTS) Consensus (CON) Group Meeting Proceedings

An international, expert led consensus initiative was set up by the Collaborative Ocular Tuberculosis Study (COTS) group to develop systematic, evidence, and experience-based recommendations for the treatment of ocular TB using a modified Delphi technique process. In the first round of Delphi, the group identified clinical scenarios pertinent to ocular TB based on five clinical phenotypes (anterior uveitis, intermediate uveitis, choroiditis, retinal vasculitis, and panuveitis). Using an interactive online questionnaires, guided by background knowledge from published literature, 486 consensus statements for initiating ATT were generated and deliberated amongst 81 global uveitis experts. The median score of five was considered reaching consensus for initiating ATT. The median score of four was tabled for deliberation through Delphi round 2 in a face-to-face meeting. This report describes the methodology adopted and followed through the consensus process, which help elucidate the guidelines for initiating ATT in patients with choroidal TB.

Development of polymorphic EST-SSR markers and their applicability in genetic diversity evaluation in Rhododendron arboreum

The genus Rhododendron, known for large impressive flowers is widely distributed throughout the world. Rhododendrons have limited genetic information, despite of comprising high species diversity, morphological overlap and weak genetic barrier. In present study, expressed sequence tag (EST) data from Rhododendron catawbiense Michx (Subgenus Hymenanthes, Section Ponticum) and Rhododendron mucronatum var. ripense (Makino) E.H. Wilson (Subgenus Tsutsusi, Section Tsutsusi) were utilized for mining and identification of the SSRs for genetic diversity analysis of R. arboreum Smith (Subgenus Tsutsusi, Section Tsutsusi). A total of 249 SSRs were developed from 1767 contigs. Di-nucleotide was found to be most abundant repeat followed by tri- and tetra-nucleotide repeats. The motif AG/CT was most common di-nucleotide motif (31.73%), whereas, AAC/GTT (8.43%), ACG/CGT (8.03%), AAG/CTT (7.23%) and AGG/CCT (6.43%) were most abundant tri-nucleotide repeat motif. Among these SSRs, 168 sequences were only fit into the criteria to design flanking primer pairs. A total of 30 randomly selected primer pairs were utilized for validation and genetic diversity study in 36 genotypes of R. arboreum collected from western Himalayan region. In aggregate, 26 SSR markers (86.66%) produced good and repeatable amplifications. Expected heterozygosity (H_E) ranged from 0.322 to 0.841 and observed heterozygosity (H_O) ranged from 0.327 to 1.000 and PIC value ranged from 0.008 to 0.786. These primers were able to distinguish the geographic differences of occurrence based on cluster analysis. These developed EST-SSRs can be useful in future population genetics analysis and micro-evolutionary studies in Rhododendron species.

Swept-source optical coherence tomography angiography of choroidal neovascularization in vertically oriented oval dome-shaped maculopathy

A 48-year-old female presented with complaints of recent onset diminution of vision of the left eye (OS) for the past 2 months. She was highly myopic and was using glasses for the past 30 years. Ocular examination revealed presence of a myopic fundus with high axial lengths in both the eyes. Fundus examination of the OS revealed a myopic tessellated fundus with prominent choroidal vessels and a blunted foveal reflex. There was a small pale whitish lesion just superior to the foveal center. Optical coherence tomography (OCT) scans (both horizontal and vertical) confirmed presence of dome-shaped maculopathy. There was subretinal fluid in the OS. A vertical OCT scan also revealed a subretinal hyperreflective material, which was confirmed to be due to a small mixed type 1 and type 2 choroidal neovascularization (CNV) on swept-source (SS) OCT angiography in the OS. The patient was given intravitreal injection of ranibizumab (0.5 mg/0.05 mL) in the OS. At 1-month follow-up, the subretinal fluid completely resolved. The CNV lesion regressed significantly on SS-OCT angiography. The best-corrected visual acuity improved from 20/80 to 20/20 in the OS, which was maintained at 3 months of follow-up.

Multiple Granulomas of Ocular Toxocariasis in an Immunocompetent Male

A 25-year-old male presented with unilateral panuveitis with multiple voluminous elevated retinal lesions along with subretinal fluid and exudation. An extensive laboratory work-up was done, and a clinical suspicion of viral retinitis was considered. The patient was initiated on antiviral therapy and, subsequently, oral corticosteroids. As the corticosteroids were tapered, the patient developed worsening lesions and vitreous inflammation. Pars plana vitrectomy (diagnostic and therapeutic) was performed and cytology sample revealed a highly eosinophilic infiltrate suggestive of parasitic infection. The real-time polymerase chain reaction was positive for Toxocara cati. The diagnosis of ocular toxocariasis was made. This case highlights a highly unusual presentation where multiple retinal granulomas of ocular toxocariasis were observed in an immunocompetent male.

An unusual case of multifocal central serous chorioretinopathy with low serum cortisol managed using eplerenone

In this report, we describe a rare case of a 44-year-old Asian male with acute central serous chorioretinopathy (CSC) with bullous exudative retinal detachment. Endocrinology evaluation revealed hypothalamic-pituitary-adrenal axis suppression with low serum cortisol. Furthermore, neuroimaging revealed the presence of a pituitary microadenoma. He was treated with systemic eplerenone and hydrocortisone. After 12 weeks, bullous detachment completely resolved. Our case is a unique description of acute CSC with underlying low serum cortisol levels that responded to treatment with mineralocorticoid antagonist. This case highlights the various endocrine abnormalities other than the raised serum cortisol that can occur in patients with CSC.

The Role of Proportional Reflux During Pars Plana Vitrectomy for Tractional Retinal Detachments

BACKGROUND AND OBJECTIVE

To discuss the role of proportional reflux hydrodissection (PRH) during pars plana vitrectomy (PPV) in eyes with diabetic tractional retinal detachment (TRD).

PATIENTS AND METHODS

In this retrospective study, records of patients with diabetic TRD involving the fovea undergoing PPV with the help of PRH between January 2015 to March 2017 were noted. PRH relies on the Constellation system's proportional reflux feature. The mean age, gender, and pre- and postoperative best-corrected visual acuity (BCVA) were noted. Minimum follow-up period of 3 months was ascertained.

RESULTS

Thirty-three patients were included. Preoperative and postoperative BCVA were 1.80 logMAR units and 1.20 logMAR units, respectively. Fifteen patients also received preoperative intravitreal ranibizumab. Twelve percent needed the help of a second instrument. Thirty-three percent developed intraoperative iatrogenic breaks, and 39.39% needed oil/gas tamponade. All patients had successful reattachments at 3-month follow-up.

CONCLUSIONS

PRH is simple, cost-effective, surgeon-friendly, and highly controlled technique helpful in managing diabetic TRD. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:113-115.].

Change in the incidence and severity of Retinopathy of Prematurity (ROP) in a Neonatal Intensive Care Unit in Northern India after 20 years: Comparison of two similar prospective cohort studies

PURPOSE

To report the change in incidence and severity of retinopathy of prematurity (ROP) in the neonatal unit of a tertiary hospital after a 20-year period.

METHODS

A prospective cohort study of one-year duration was conducted between July 2013 and June 2014 in the neonatal intensive care unit (NICU) of a tertiary hospital. Inborn babies with birth weight ≤1700 g and gestational age ≤37 weeks were included. Change in incidence and severity of ROP were compared to a similar study in the same NICU between January and December 1993.

RESULTS

The 2013 study included higher numbers of newborn infants than the 1993 study (293 vs. 157). The mean (SD) birth weight and gestational age of the infants in the 2013 study were significantly lower than the 1993 study [1288.6 (229.8) vs. 1378.1 (232.6) g); p = 0.0001 and 31.7 (2.1) vs. 32.2 (2.31) weeks; p = 0.04]. Nevertheless, the overall incidence of ROP decreased from 49% to 26.6% (p < 0.001) after the 20-year interval. The incidence of stage 3 ROP decreased non-significantly from 24.7% to 12.8% (p = 0.058). Multivariate logistic regression analysis showed that birth weight ≤1250 g and belonging to the 1993 cohort were independently associated with an increased risk of ROP after adjusting for covariates (p = 0.013).

CONCLUSION

The incidence of ROP improved significantly over a 20-year period in association with improved NICU management strategies despite an increase in the number of eligible neonates with lower birth weights and gestational ages.

Safety and efficacy of dexamethasone implant along with phacoemulsification and intraocular lens implantation in children with juvenile idiopathic arthritis associated uveitis

PURPOSE

To assess the safety and efficacy of intraoperative intravitreal dexamethasone implant in patients of juvenile idiopathic arthritis (JIA)-associated uveitis undergoing phacoemulsification with posterior chamber intraocular lens (PCIOL) implantation.

METHODS

Retrospectively, data of patients with JIA-associated uveitis undergoing phacoemulsification with PCIOL implantation with intraoperative dexamethasone implant injection were analyzed. Patients with a minimum follow-up of 6 months were included. Primary outcome measures were ocular inflammation, intraocular pressure (IOP), best-corrected visual acuity (BCVA), and worsening of uveitis.

RESULTS

8 eyes of 6 patients were included. BCVA was significantly improved at 1, 3, and 6 months postoperatively 0.20 ± 0.09, P = 0.008; 0.18 ± 0.11, P = 0.008; and 0.24 ± 0.11, P = 0.01, respectively. No statistical difference noted in mean IOP at various follow-up visits. None developed worsening of uveitis or Cystoid macular edema.

CONCLUSION

Intraoperative intravitreal dexamethasone implant is a safe and effective in preventing and managing the postoperative inflammation in children with JIA-associated uveitic cataract.