Management of diabetic macular oedema in France from 2012 to 2018: The nationwide LANDSCAPE study

OBJECTIVE

To describe the management of diabetic macular oedema (DME) patients from the entire French population between 2012 and 2018.

METHODS

In this retrospective longitudinal study, we identified adults treated for DME from the French population using the exhaustive French National Health Information database (SNDS), and an algorithm based on diagnosis and procedure codes, and reimbursed treatments.

RESULTS

Between 2012 and 2018, we identified 53 584 treated DME patients, who were followed for up to 7 years from DME treatment initiation. Optical coherence tomography (OCT) became the predominant imaging tool to diagnose DME. Only 14% of patients consulted a diabetologist or endocrinologist in the 3 months prior to initiating DME treatment, whereas 84% consulted a general practitioner. The percentage of patients consulting an ophthalmologist declined over time, from 97% of patients in Year 1 (median of 9 consultations), to 46% in Year 7 (median of 7 consultations). The median DME treatment duration with an anti-VEGF and/or dexamethasone implant treatment was 9 months; 54% of patients had a treatment duration less than 1 year. First-line treatment was more common with ranibizumab (55% of patients) than with aflibercept (30%), or dexamethasone implant (15%). About 25% of patients who initiated anti-VEGF treatment switched treatment at least once, while 30% of patients who initiated dexamethasone implant switched to anti-VEGF treatment at least once.

CONCLUSIONS

French DME patients seem well-monitored by their ophthalmologist, but median DME treatment duration was just 9 months. These results emphasise the challenge to manage and treat patients with DME over the long term.

Management of Neovascular Age-Related Macular Degeneration Treatment in France from 2008-2018: The Nationwide LANDSCAPE Study

INTRODUCTION

The aim of this study was to describe the management of neovascular age-related macular degeneration (nAMD) in French patients between 2008 and 2018.

METHODS

This was a retrospective longitudinal cohort study using exhaustive nationwide health records from the French National Health Information database. Enrollment criteria were adults aged ≥ 50 years, nAMD diagnosis, or reimbursement for nAMD treatments (anti-vascular epithelial growth factor [VEGF] injection or dynamic phototherapy with verteporfin). Exclusion criteria were high myopia, diagnosis of other retinal diseases, and treatments for other macular diseases (dexamethasone implant, laser). Main outcome measures were consumption of medical care and nAMD treatments per calendar year and number of years of follow-up.

RESULTS

Between 2008 and 2018, we identified 342,961 patients who have been treated for nAMD. Median duration of ophthalmological follow-up exceeded 7 years (90 months). The median annual number of ophthalmology consultations decreased from nine visits in year 1 after treatment initiation to four visits from year 7 onwards. The median duration of nAMD treatment was 10.1 months for all patients, with 48.5% of patients undergoing treatment for < 1 year. Only 24.4% of patients had maintained treatment at year 11. Patients remaining under treatment had a median of four anti-VEGF treatments per year throughout the 10-year study period. Ranibizumab was the more common first-line treatment (67.5% of patients) compared to aflibercept (32.4%). About 20% of patients who initiated treatment switched treatment at least once.

CONCLUSIONS

LANDSCAPE provides exhaustive nationwide data on the real-world management of nAMD in France over a 10-year period. Further investigation into short treatment duration is required, especially in terms of understanding its relation to visual outcomes.

Marine records reveal multiple phases of Toba's last volcanic activity

The Indonesian Young Toba Tuff (YTT), classically dated around 74 ka BP, is considered as a short-lived explosive cataclysmic super-eruption. The huge amounts of ash and SO₂ emitted are likely to have triggered a volcanic winter which accelerated the transition to the last glaciation, and may have induced a human genetic bottleneck. However, the global climatic impact of the YTT or its duration are hotly debated. The present work offers a new interpretation of the Toba volcanic complex eruptive history. Analysing the BAR94-25 marine core proximal to the Toba volcanic center and combining it with high-resolution tephrostratigraphy and δ¹⁸O stratigraphy, we show that the Toba complex produced a volcanic succession that consists of at least 17 distinct layers of tephra and cryptotephra. Textural and geochemical analyses show that the tephra layers can be divided in 3 main successive volcanic activity phases (VAP1 to VAP3) over a period of ~ 50 kyr. The main volcanic activity phase, VAP2, including the YTT, is likely composed of 6 eruptive events in an interval whose total duration is ~ 10 ka. Thus, we suggest that the eruptive model of the Toba volcano must be revised as the duration of the Toba volcanic activity was much longer than suggested by previous studies. The implications of re-estimating the emission rate and the dispersion of ashes and SO₂ include global environmental reconstitutions, climate change modelling and possibly human migration and evolution.

Impact of COVID-19 lockdown on surgical procedures for retinal detachment in France: a national database study

BACKGROUND/AIMS

The COVID-19 crisis and the decisions made regarding population lockdown may have changed patient care. We aimed to investigate the incidence rate of rhegmatogenous retinal detachment (RRD) cases during the COVID-19 lockdown period.

METHODS

In this nationwide database study, we identified hospital and clinic admissions of French residents for a first episode of RRD in France from 2017 to the lockdown period in 2020. The monthly hospital incidence rates of RRD procedures per 100 000 inhabitants before, during and after lockdown were computed for the whole country. Finally, we assessed the influence of viral incidence on the RRD incidence rate, comparing two regions with highly contrasting viral penetration.

RESULTS

From January to July, the average monthly national hospital incidence rate of RRD decreased from a mean of 2.59/100 000 inhabitants during 2017-2019 to 1.57/100 000 inhabitants in 2020. Compared with 2019, during the 8-week lockdown period in 2020, a 41.6% decrease in the number of RRD procedures was observed (p<0.001) with the weekly incidence of RRD decreasing from 0.63/100 000 inhabitants in 2019 to 0.36/100 000 inhabitants. During the 4-month post-lockdown period, no increased activity related to postponed procedures was observed. No difference was found in the rate of RRD surgery when comparing two regions with highly contrasting viral incidence.

CONCLUSION

Containment may have been responsible for a decrease in the number of surgical procedures for RRD, without any compensating post-lockdown activity in France. These results might help increase awareness of the management of RRD emergencies.

Effects of topical docosahexaenoic acid on postoperative fibrosis in an animal model of glaucoma filtration surgery

PURPOSE

The aim of this study was to evaluate docosahexaenoic acid (DHA) as a potential antifibrotic agent after glaucoma filtration surgery (GFS) in rats.

METHODS

A total of 36 10-week-old Brown Norway rats underwent GFS. Animals were equally divided into three groups: a control group, a DHA group and a mitomycin C (MMC) group. Intraocular pressure (IOP) was measured using a dynamic rebound tonometer, and a photograph of the surgical site was taken on days 1, 3, 7, 10, 14 and 17. The incorporation of DHA into fibroblasts was evaluated by gas chromatography. The expression of alfa-smooth muscle actin (α-SMA) and Smad proteins was assessed by Western blotting.

RESULTS

IOP decreased after surgery in animals from the three groups on day 1 after surgery. Over time, IOP remained lower in the DHA and MMC groups than in the control group (median [interquartile range] 8.0 [7.0-8.0] and 8.0 [7.3-8.0] mmHg vs. 9.0 [8.0-9.0] mmHg, respectively; p < 0.001). Bleb area in the DHA and MMC groups remained larger than that of the control group from day 7 to day 14 (3.9 [2.9-5.2] and 3.5 [2.3-4.4] mm² vs. 2.3 [2.0-2.8] mm² , respectively; p = 0.0021). We did not observe any change in DHA concentrations in the fibroblasts of the DHA group compared with the other groups.

CONCLUSION

The impact of DHA on IOP and bleb area was similar to that of MMC. The mechanisms of action of DHA in rat eye fibroblasts deserve further investigation.

Epidemiology of Treated Diabetes Ocular Complications in France 2008-2018-The LANDSCAPE French Nationwide Study

AIM

LANDSCAPE aimed to estimate the annual incidence and prevalence of treated diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR) between 2008 and 2018.

METHODS

This French nationwide observational study used data from the French National Health Insurance Databases covering 99% of the French population. Data about healthcare consumption were used to identify adults treated with anti-VEGFs or dexamethasone implants (for DME) and with pan-retinal photocoagulation (for PDR). All French patients newly treated between 2008 and 2018 were included. Incidence and prevalence of treated DME and PDR were estimated for the age-matched general population and the population with diabetes in France. Sociodemographic characteristics and medical history were described in both populations.

RESULTS

We identified 53,584 treated DME patients and 127,273 treated PDR patients between 2008 and 2018, and 11,901 DME and 11,996 PDR new incident patients in 2018. The treated DME incidence in 2018 was 2.5 per 10,000 in the general population and 37.3 per 10,000 in the population with diabetes. Prevalence in 2018 was 9.5 and 143.7 per 10,000 in the respective populations. Treated PDR incidence in 2018 was 2.3 per 10,000 in the general population and 31.2 per 10,000 in the population with diabetes. Prevalence in 2018 was 19.9 and 270.3 per 10,000 in the respective populations. Incidence and prevalence were not age-dependent. Incidence of treated PDR incidence was relatively stable from 2008-2018. Incidence of treated DME incidence rose from 2012-2018, probably due to widening access to newly available treatments, such as anti-VEGFs.

CONCLUSIONS

We provide exhaustive nationwide data on the incidence and prevalence of treated diabetic ocular complications in France over a 10-year period.

Topical Antibiotic Prophylaxis and Intravitreal Injections: Impact on the Incidence of Acute Endophthalmitis-A Nationwide Study in France from 2009 to 2018

Background: The dramatic increase in intravitreal injections (IVTs) has been accompanied by a greater need for safer procedures. The ongoing debate about topical antibiotic prophylaxis after IVTs emphasizes the importance of large-scale studies. We aimed to study the role of topical antibiotic prophylaxis in reducing the risk of acute endophthalmitis after IVTs. Methods: Population-based cohort study, in France, from 2009 to 2018, including all French patients receiving IVTs of corticosteroids or anti-VEGF agents. Results: A total of 5,291,420 IVTs were performed on 605,434 patients. The rate of topical antibiotic prophylaxis after IVTs progressively decreased during the study period, with a sharp drop in 2014 (from 84.6% in 2009 to 27.4% in 2018). Acute endophthalmitis occurred in 1274 cases (incidence rate = 0.0241%). Although antibiotic prophylaxis did not alter the risk of endophthalmitis (p = 0.06), univariate analysis showed an increased risk after fluoroquinolone and aminoglycoside prophylaxis. This increased risk was not found in multivariate analysis. However, we observed an increased risk related to the use of fixed combinations of fluoroquinolones and aminoglycosides with corticosteroids (IRR = 1.89; 95% CI = 1.57–2.27%, antibiotics combined with corticosteroids). Conclusion: These results are consistent with the literature. Endophthalmitis rates after IVTs did not decrease with topical antibiotic prophylaxis. The use of a combination of antibiotics and corticosteroids doubles the risk of endophthalmitis and should be avoided. Avoiding antibiotic prophylaxis would reduce the costs and the potential risks of antibiotic resistance.

Cystoid Macular Edema after Rhegmatogenous Retinal Detachment Repair with Pars Plana Vitrectomy: Rate, Risk Factors, and Outcomes

(1) Background: The aim was to describe the rate and outcomes of cystoid macular edema (CME) after pars plana vitrectomy (PPV) for primary rhegmatogenous retinal detachment (RRD) and to identify risk factors and imaging characteristics. (2) Methods: A retrospective consecutive case study was conducted over a 5-year period among adult patients who underwent PPV for primary RRD repair. The main outcome measure was the rate of CME at 12 months following PPV. (3) Results: Overall, 493 eyes were included. The CME rate was 28% (93 patients) at 12 months. In multivariate analysis, eyes with worse presenting visual acuity (VA) (odds ratio [OR], 1.55; 95% CI, 1.07–2.25; p = 0.02) and grade C proliferative vitreoretinopathy (PVR) (OR, 2.88; 95% CI, 1.04–8.16; p = 0.04) were more at risk of developing CME 1 year after PPV. Endolaser retinopexy was associated with a greater risk of CME than cryotherapy retinopexy (OR, 3.06; 95% CI, 1.33–7.84; p = 0.01). Eyes undergoing cataract surgery within 6 months of the initial RRD repair were more likely to develop CME at 12 months (OR, 1.96; 95% CI, 1.06–3.63; p = 0.03). (4) Conclusions: CME is a common complication after PPV for primary RRD repair. Eyes with worse presenting VA, severe PVR at initial presentation, endolaser retinopexy, and cataract surgery within 6 months of initial RRD repair were risk factors for postoperative CME at 12 months.

Incidence of rhegmatogenous retinal detachment following macular surgery in France between 2006 and 2016

PURPOSE

To report the incidence of postoperative rhegmatogenous retinal detachment after macular surgery in France between 2006 and 2016 and identify associated factors.

DESIGN

Nationwide population-based cohort study.

METHODS

All surgical procedures for an epiretinal membrane or a macular hole performed in France from January 1, 2006 to October 31, 2016 were identified in the French national administrative database (Programme de Médicalisation des Systèmes d'Information). We investigated the incidence of rhegmatogenous retinal detachment occurring within 90 days of a macular surgical procedure.

RESULTS

From January 1, 2006 to October 31, 2016, 152,034 macular surgical procedures for epiretinal membranes or macular holes were recorded in France. We identified 3,605 cases of rhegmatogenous retinal detachment occurring within 90 days of the procedure. The incidence of rhegmatogenous retinal detachment was 2.37% overall, 1.95% for epiretinal membrane surgery and 3.43% for macular hole surgery. In multivariable Poisson regression analysis, rhegmatogenous retinal detachment was associated with macular hole surgery (incidence rate ratio [IRR], 1.76; 95% CI, 1.63-1.90; P < .001), history of cataract extraction in the previous year (IRR, 1.20; 95% CI, 1.08-1.34; P = .001), age < 60 years (P < .001), and male gender (IRR, 1.63; 95% CI, 1.51-1.76; P < .001).

CONCLUSIONS

The incidence of rhegmatogenous retinal detachment within 90 days of macular surgery was 2.37% overall in France between 2006 and 2016 and it was higher for macular hole surgery than for epiretinal membrane surgery.

Repeatability and Reproducibility of Retinal Fractal Dimension Measured with Swept-Source Optical Coherence Tomography Angiography in Healthy Eyes: A Proof-of-Concept Study

The retinal vascular network fractal dimension (FD) could be a promising imaging biomarker. Our objective was to evaluate its repeatability and reproducibility in healthy eyes. A cross-sectional study was undertaken with young, healthy volunteers who had no reported cardiac risk factors or ocular disease history. For each participant, three SS-OCTA images (12 × 12 mm) were acquired using the Plex Elite 9000 (Carl Zeiss Meditec AG, Jena, Germany) by two ophthalmologists. Automated segmentation was obtained from both the superficial and deep capillary plexuses. FD was estimated by box counting. The intraclass correlation coefficients (ICC) were used as measures for repeatability and reproducibility. A total of 43 eyes of healthy volunteers were included. The mean ± standard deviation (SD) age was 30 ± 6.2 years. The results show good repeatability. The ICC was 0.722 (95% CI, 0.541–0.839) in the superficial capillary plexus and 0.828 (95% CI, 0.705–0.903) in the deep capillary plexus. For reproducibility, the ICC was 0.651 (95% CI, 0.439–0.795) and 0.363 (95% CI, 0.073–0.596) at the superficial and deep capillary plexus, respectively. In this study, the FD of the vascular network measured via SS-OCTA showed good repeatability and reproducibility in healthy participants.

IMPACT study: Impact of adherence to anti-VEGF intravitreal injections for macular disease during COVID 19-related confinement in France

PURPOSE

The aim of this study was to evaluate the impact of adherence to French coronavirus disease 2019 (COVID 19)-related guidelines for intravitreal injection (IVI) practice on the visual outcomes of patients treated with anti-vascular endothelial growth factor (VEGF) agents for macular diseases during the first lockdown period.

METHODS

Observational multicentre study including all patients from 18 centres with an IVI initially planned during the lockdown. Visual acuity (VA, ETDRS) was recorded at 1 and 4 months after lockdown. French COVID 19-related guidelines recommended maintaining IVI practice. We defined three groups of patients: A, adherent to guidelines; NA+, non-adherent with delayed IVIs; and NA-, non-adherent without IVIs performed during the lockdown. Risk factors for non-adherence and visual loss were studied.

RESULTS

A total of 3020 eyes of 3020 patients, aged 77.8 ± 11.6 years, 59.8% women, were included. 59.3% were non-adherent(46.7% NA+, 12.6% NA-). A smaller decrease in VA at 4 months was observed in the A group than the NA+ and NA- group (-0.2 ± 6.7, -0.3 ± 6.9 and -1.5 ± 6.9, respectively [p < 0.001]). Factors associated with non-adherence were in multivariable analysis, older age, hospital practice, low-density population areas, high viral incidence areas, longer intervals between injection and treat and extent protocol. Factors associated with visual loss at 4 months in multivariable analysis were, being in the NA- group, older age, T&E and fixed regimens.

CONCLUSION

Strict adherence to guidelines was associated with better visual outcome, although most of our patients did not attend as planned. Identification of patients at risk could help in the future in case of a new pandemic lockdown.

Epidemiology of Acute Endophthalmitis after Intraocular Procedures: A National Database Study

OBJECTIVE

To describe the causes of postoperative acute endophthalmitis at the national level longitudinally.

DESIGN

Cohort study from 2009 to 2018 in France.

PARTICIPANTS

Patients diagnosed with acute endophthalmitis after intraocular procedures.

METHODS

The French medical-administrative database was used. Endophthalmitis cases and intraocular procedures were identified based on billing codes in all French hospitals and private practices.

MAIN OUTCOME MEASURES

The incidence of acute endophthalmitis within 42 days of the procedure.

RESULTS

From January 1, 2009, to October 31, 2018, 7522 cases of acute endophthalmitis occurred after 14 438 854 intraocular procedures. Most cases occurred after standalone cataract surgery (4808 cases for 7 316 077 procedures; 63.92%), followed by after intravitreal (IVT) injections (1296 cases for 5 455 631 IVT injections; 17.23%), vitreoretinal surgery (698 for 442 263 procedures; 9.28%), anterior segment surgery (245 cases; 3.26%), combined cataract and vitreoretinal surgery (191 cases; 2.54%), cornea surgery (142 cases; 1.89%), and glaucoma surgery (80 cases; 1.06%). The overall incidence of acute endophthalmitis was 1 per 1920 procedures (0.0521%; 95% confidence interval [CI], 0.0520-0.0522). The surgery with the highest incidence of endophthalmitis was scleral and globe surgery, with an incidence of 0.1827% (95% CI, 0.1757-0.1898), followed by vitreoretinal surgery combined with cataract surgery, with an incidence of 0.1685% (95% CI, 0.1663-0.1706). The incidence of endophthalmitis after IVT injections was stable over the study period, and patients receiving IVT injections were the oldest, aged 75.4 years (standard deviation, 12.0 years; P < 0.001). The onset of endophthalmitis after IVT procedures, i.e, after receiving IVT injections or undergoing vitreoretinal surgery, was earlier than that after the other procedures (P < 0.001).

CONCLUSIONS

The profile of patients referred for acute endophthalmitis has been evolving over the past decade, with a decrease in the raw number of endophthalmitis cases after cataract surgery as opposed to an increase in the number of patients presenting with endophthalmitis after IVT injections.

Precipitation of greigite and pyrite induced by Thermococcales: an advantage to live in Fe- and S-rich environments?

Thermococcales, a major order of archaea inhabiting the iron- and sulfur-rich anaerobic parts of hydrothermal deep-sea vents, have been shown to rapidly produce abundant quantities of pyrite FeS₂ in iron-sulfur-rich fluids at 85°C, suggesting that they may contribute to the formation of 'low temperature' FeS₂ in their ecosystem. We show that this process operates in Thermococcus kodakarensis only when zero-valent sulfur is directly available as intracellular sulfur vesicles. Whether in the presence or absence of zero-valent sulfur, significant amounts of Fe₃ S₄ greigite nanocrystals are formed extracellularly. We also show that mineralization of iron sulfides induces massive cell mortality but that concomitantly with the formation of greigite and/or pyrite, a new generation of cells can grow. This phenomenon is observed for Fe concentrations of 5 mM but not higher suggesting that above a threshold in the iron pulse all cells are lysed. We hypothesize that iron sulfides precipitation on former cell materials might induce the release of nutrients in the mineralization medium further used by a fraction of surviving non-mineralized cells allowing production of new alive cells. This suggests that biologically induced mineralization of iron-sulfides could be part of a survival strategy employed by Thermococcales to cope with mineralizing high-temperature hydrothermal environments.

Bilateral acute macular neuroretinopathy in a young woman after the first dose of Oxford-AstraZeneca COVID-19 vaccine

Purpose

To report a case of bilateral acute macular neuroretinopathy following the first dose of Oxford-AstraZeneca COVID-19 (coronavirus disease 2019) vaccine in a young, Caucasian, and healthy woman.

Observations

A 25-year-old Caucasian female patient presented to the ophthalmology department of Dijon University Hospital with a 3-week history of black spots and paracentral scotoma in both eyes. She had no past medical history and was using the combined estrogen-progestin oral contraceptive (COC). These symptoms occurred 24 h after receiving the first Oxford-AstraZeneca COVID-19 vaccination dose. The ophthalmologic signs were preceded a few hours earlier by fever and flu-like symptoms. Ophthalmologic examination revealed a preserved visual acuity with a quiet anterior segment and normal fundus in both eyes. Findings on multimodal retinal imaging, particularly near-infrared reflectance (NIR) and optical coherence tomography (OCT) imaging, were classical of an acute macular neuroretinopathy in both eyes.

Conclusions and importance

COVID-19 vaccination is justified as an essential public health measure. Acute macular neuroretinopathy may occur in patient receiving a COVID-19 vaccination dose. Further reports are needed to confirm this association. Physicians should be aware of this complication and request an eye examination with at least OCT or NIR imaging in the case of any visual symptoms after vaccination, notably in young women using COC.

Prediction of Cardiovascular Parameters With Supervised Machine Learning From Singapore "I" Vessel Assessment and OCT-Angiography: A Pilot Study

Purpose

Assessment of cardiovascular risk is the keystone of prevention in cardiovascular disease. The objective of this pilot study was to estimate the cardiovascular risk score (American Hospital Association [AHA] risk score, Syntax risk, and SCORE risk score) with machine learning (ML) model based on retinal vascular quantitative parameters.

Methods

We proposed supervised ML algorithm to predict cardiovascular parameters in patients with cardiovascular diseases treated in Dijon University Hospital using quantitative retinal vascular characteristics measured with fundus photography and optical coherence tomography – angiography (OCT-A) scans (alone and combined). To describe retinal microvascular network, we used the Singapore “I” Vessel Assessment (SIVA), which extracts vessel parameters from fundus photography and quantitative OCT-A retinal metrics of superficial retinal capillary plexus.

Results

The retinal and cardiovascular data of 144 patients were included. This paper presented a high prediction rate of the cardiovascular risk score. By means of the Naïve Bayes algorithm and SIVA + OCT-A data, the AHA risk score was predicted with 81.25% accuracy, the SCORE risk with 75.64% accuracy, and the Syntax score with 96.53% of accuracy.

Conclusions

Performance of these algorithms demonstrated in this preliminary study that ML algorithms applied to quantitative retinal vascular parameters with SIVA software and OCT-A were able to predict cardiovascular scores with a robust rate. Quantitative retinal vascular biomarkers with the ML strategy might provide valuable data to implement predictive model for cardiovascular parameters.

Translational Relevance

Small data set of quantitative retinal vascular parameters with fundus and with OCT-A can be used with ML learning to predict cardiovascular parameters.

Functional and anatomical outcomes after successful repair of macula-off retinal detachment: a 12-month follow-up of the DOREFA study

PURPOSE

To report visual and anatomical outcomes and determine predictors of good visual acuity (VA) recovery after macula-off rhegmatogenous retinal detachment (RD).

METHODS

Prospective multicentre study including 115 eyes from 115 patients successfully operated on for RD, with assessment of VA and spectral-domain optical coherence tomography (SD-OCT) macular images at 1, 3, 6 and 12 months after surgery.

RESULTS

Over the follow-up period, VA significantly improved from median [IQR] 62 [46; 72] ETDRS letters at 1 month to 75 [67; 80] ETDRS letters at 12 months (p < 0.001) with a concomitant decreased number of eyes with any SD-OCT lesions (p < 0.001). The presence of subretinal fluid (SRF) significantly decreased (p < 0.001), as did the number of photoreceptor (PR) layer lesions (p = 0.04). At 12 months, lesions in the PR layer and poor VA recovery were significantly associated with a longer time to surgery (p = 0.007 and p < 0.001, respectively). The rate of patients without PR lesions increased from 40.9% at 1 month to 60.0% at 6 months and 73.9% at 12 months (p < 0.001). The incidence of epiretinal membrane (ERM) significantly increased (p < 0.001), while cystoid macular oedema (CME) remained stable over time. Visual acuity (VA) at 3 months postoperatively was a good reflection of final VA recovery (p < 0.001).

CONCLUSION

Visual acuity (VA) improved in parallel with the decreasing number of eyes with SD-OCT lesions after macula-off rhegmatogenous RD. A long time to surgery was the only preoperative factor associated with poor VA recovery after retinal detachment surgery.

Quality-of-Life Improvement After Scleral Lens Fitting in Patients With Keratoconus

OBJECTIVES

To assess the quality-of-life improvement after scleral lens fitting in patients with keratoconus.

METHODS

We conducted a prospective observational study of all consecutive patients with keratoconus starting scleral lens fitting in 2019, from January 2 to December 27, at the Dijon University Hospital, France. Quality of life was assessed before and after wearing scleral lenses for 3 months through the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ 25) questionnaire. We investigated factors potentially influencing quality of life: final visual acuity, keratoconus stage, and maximum keratometry reading.

RESULTS

In total, 41 eyes of 24 patients were successfully fitted with scleral lenses, 92.9% were 18 mm in diameter and 7.1% were 17 mm. The visual acuity improved by -0.4±0.3 logarithm of the minimum angle of resolution (P<0.001) after scleral lens fitting. Visual gain increased with keratometry and keratoconus severity (P<0.001; P<0.01). The NEI-VFQ 25 score increased by 19.5±19.1 points on average (P<0.001). No association was found between the factors under study and improvement in quality of life.

CONCLUSION

Our study confirms the functional improvement in patients with keratoconus fitted with scleral lenses, especially in patients with more advanced disease. Moreover, it suggests a major role of these lenses in improving quality of life, independently of the severity of the disease and the visual gain.

ASSOCIATION BETWEEN ANATOMICAL AND CLINICAL OUTCOMES OF NEOVASCULAR AGE-RELATED MACULAR DEGENERATION TREATED WITH ANTIVASCULAR ENDOTHELIAL GROWTH FACTOR

PURPOSE

Assess the relationship between subretinal fluid (SRFL), intraretinal fluid, and visual outcomes of neovascular age-related degeneration in routine clinical practice.

METHODS

Treatment-naive eyes enrolled in the Fight Retinal Blindness! registry after January 2017 were identified. Lesion activity was graded at each visit as inactive, active not SRFL only (A-NSRFL only), or active SRFL only (A-SRFL only). Eyes were grouped based on initial activity as follows: 1) initially A-NSRFL only or 2) initially A-SRFL only, and their predominant activity status over 12 months was as follows: 1) mostly inactive, 2) mostly A-NSRFL only, or 3) mostly A-SRFL only.

RESULTS

Seven hundred and three eyes were eligible for analysis. Initially A-NSRFL only had a similar adjusted mean 12-month visual acuity change to initially A-SRFL eyes (5.7 vs. 6.9 letters; P = 0.165), but their final visual acuity was worse (62.5 vs. 67.5 letters at 12 months; P = 0.003). The adjusted mean 12-month visual acuity change between the predominant activity groups was significantly different (P = 0.005), with mostly inactive (7.6 letters) and mostly A-SRFL only (7.5 letters) eyes gaining more than mostly A-NSRFL only eyes (3.6 letters).

CONCLUSION

Eyes with SRFL only had similar outcomes at 1 year to eyes that were mostly inactive. Intraretinal fluid was associated with worse visual outcomes, highlighting the importance of distinguishing between intraretinal fluid and SRFL when managing neovascular age-related degeneration.

Incidence of rhegmatogenous retinal detachment in France from 2010 to 2016: seasonal and geographical variations

AIMS

To investigate the annual and monthly hospital incidence rate of rhegmatogenous retinal detachments (RRDs) from 2010 to 2016 in France at the national and regional levels.

METHODS

In this nationwide database study, we identified hospital and clinic admissions of French residents for a first episode of RRD in France during 2010-2016 from the national administrative database. The annual and monthly hospital incidence rates of RRD per 100 000 population were calculated for the whole country and for each region.

RESULTS

The average annual national hospital incidence rate of RRD was 21.97±1.04 per 100 000 population. The annual national hospital incidence rate of RRD was the lowest in 2010 (20.91 per 100 000 population) after which it increased until 2015 (23.55 per 100 000 population). The average monthly national RRD hospital incidence rate was the highest in June (2.03±0.12 per 100 000 population) and the lowest in August (1.60±0.09). The average annual age-standardised and sex-standardised regional hospital incidence rate was the highest in Guadeloupe and Pays de la Loire (28.30±2.74 and 26.13±0.84 per 100 000 population, respectively) and the lowest in French Guiana and Martinique (15.51±3.50 and 17.29±2.12 per 100 000 population, respectively).

CONCLUSIONS

The average annual national hospital incidence rate of RRD increased from 2010 to 2015. The hospital incidence rate of RRD seemed to vary according to season and geographical location.

Subcapularis tendon tear: A structure-based arthroscopic description

INTRODUCTION

Subscapularis (SSC) tendons differ from supraspinatus tendons, although both have similar histologic structure comprising two layers with distinct collagen fiber organization.

HYPOTHESIS

The partial/full-thickness tear classification for the supraspinatus based on tendon structure can be applied to the subscapularis tendon on objective criteria.

MATERIAL AND METHODS

The present study used 100 films of arthroscopic rotator cuff repair involving SSC lesion. Lesions were reported on 3 objective criteria: horizontal superior tendon edge visibility, lesser tuberosity bone exposure, and lateral tendon edge visibility. Combining the three distinguishes deep, superficial or interstitial partial tear versus full-thickness tear. Degree of retraction was also noted.

RESULTS

Forty-six of the 73 partial lesions involved the deep articular layer, which was often retracted, but conserving the horizontal superior tendon edge and thus misleadingly suggesting SSC integrity; 23 were interstitial, without detachment from the lesser tuberosity; 4 involved only the superficial layer. Full-thickness tears were always retracted, with loss of horizontal superior tendon edge, visibility of the lateral tendon edge and presence of comma sign. Inter- and intra-observer reproducibility was satisfactory.

DISCUSSION - CONCLUSION

Like in superior cuff tear, a structure-based classification can be made of SSC lesions on objective criteria.

LEVEL OF EVIDENCE

IV.

Impact of flow and temperature on non-dyspnoeic dogs' tolerance undergoing high-flow oxygen therapy

OBJECTIVES

To prospectively describe the impact of gas flow rate and temperature on dog's tolerance of high-flow nasal oxygen therapy during recovery from anaesthesia, hypothesizing that higher flow rates and temperatures will decrease tolerance.

MATERIALS AND METHODS

Twelve non-dyspnoeic client-owned dogs recovering from general anaesthesia were included in this study. After extubation, a nasal cannula was positioned and high-flow nasal oxygen therapy was initiated. Two flow rates (two or four time the theoretical minute ventilation: HF2 and HF4), each of them combined with two temperatures (31 and 37°C: T31 and T37), were randomly applied (four conditions per dog). For each condition, cardiovascular and respiratory parameters (heart rate, respiratory rate, systolic arterial blood pressure and pulse oximeter oxygen saturation), sedation score and tolerance score were recorded at initiation (T₀ ) and after 10 minutes of accommodation (T₁₀ ).

RESULTS

Sedation scores were not significantly different between the four conditions. Cardiovascular and respiratory parameters were not significantly different between any condition at both T₀ and T₁₀ . Tolerance scores were good and not significantly different between any flow rate or temperature (HF2-T31: 4 (2-4), HF4-T31: 4 (2-4), HF2-T37: 4 (2-4), HF4-T37: 4 (1-4)).

CLINICAL SIGNIFICANCE

The gas flow rates and temperatures studied have no impact on tolerance during the recovery period of non-dyspnoeic dogs, and high-flow nasal cannula is well tolerated. Further studies are required to confirm these results in dyspnoeic dogs.

The Invisible MGHL Test: Diagnostic Value and Benefits for the Repair of Retracted Subscapularis Tears

BACKGROUND

Some full-thickness subscapularis tendon tears and partial tears of the deep layer are difficult to characterize, leading to misdiagnosis.

PURPOSE

To evaluate the association between displacement of the middle glenohumeral ligament (MGHL) and retracted tears of the subscapularis tendon as a possible test to improve diagnosis.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Videos (N = 100) recorded during arthroscopic rotator cuff repair involving a torn subscapularis tendon were analyzed retrospectively to assess the association between the MGHL test (nonvisibility of the MGHL) and other objective anatomic criteria. The invisible MGHL test was defined as positive if the MGHL was initially nonvisible in the beach-chair position and appeared only when the subscapularis tendon was pulled back into position by using a 30° arthroscope from the standard posterior portal. The parameters considered during the initial exploration were (1) visibility of the horizontal part of the subscapularis tendon; (2) visibility of the MGHL in its usual position, crossing the superior border of the subscapularis tendon; (3) exposure of the lateral border of the subscapularis tendon (full-thickness retracted tear); and (4) complete or partial exposure of the lesser tuberosity of the humerus. Tendon retraction was evaluated in 3 stages according to the Patte classification.

RESULTS

The invisible MGHL test result was positive in 45% of cases. It was positive in 6% of cases (2 of 31) when there was no subscapularis tendon retraction and in 62% of cases (43 of 69) when there was partial or complete retraction (P < .001). The invisible MGHL test was significantly associated with the width of the tear (P < .001) and exposure of the lateral border of the subscapularis tendon (full-thickness retracted tear, P = .0002). After repair, the MGHL was visible in its anatomic position in 96% of cases.

CONCLUSION

A positive invisible MGHL test is an alternative indication of subscapularis tendon retraction, and the relocation of the MGHL can also be used after repair to assess the proper anatomic repositioning of the subscapularis tendon.

Incidence of acute postoperative endophthalmitis following macular surgery in France between 2006 and 2016

PURPOSE

To report the incidence of acute postoperative endophthalmitis (POE) after macular surgery in France between 2006 and 2016 and to identify associated factors.

METHODS

This retrospective database study included all hospital discharge records involving a surgical procedure for an epiretinal membrane or a macular hole in France from January 2006 to October 2016. Acute POE was identified by two codes in the tenth edition of the International Classification of Diseases within 42 days of a macular surgical procedure in the French national administrative database.

RESULTS

In France, 152 034 macular surgical procedures for epiretinal membranes or macular holes were recorded from 1 January 2006 to 31 October 2016. Suspected acute POE was reported in 381 cases. The incidence of POE was 0.25% overall, 0.30% for epiretinal membrane surgery and 0.14% for macular hole surgery. In multivariable Poisson regression analysis, epiretinal membrane surgery was associated with POE [incidence rate ratio (IRR), 2.24; 95% CI, 1.62-3.11; p < 0.001]. For epiretinal membrane surgery, the 2010-2011 period was significantly associated with a higher risk of POE (IRR, 1.66; 95% CI, 1.13-2.42; p = 0.03).

CONCLUSION

The incidence of POE after macular surgery was 0.25% overall in France between 2006 and 2016 and twice higher for epiretinal membrane surgery than for macular hole surgery. For epiretinal surgery only, the incidence of POE was higher in 2010-2011 (period of the switch to transconjunctival vitrectomy) than in the rest of the study period.

Influence of cardiac hemodynamic variables on retinal vessel density measurement on optical coherence tomography angiography in patients with myocardial infarction

INTRODUCTION

Quantitative measurements of retinal microvasculature by optical coherence tomography angiography (OCT-A) have been used to assess cardiovascular risk profile. However, to date, there are no studies focusing on OCT-A imaging in the setting of the altered hemodynamic status found in high-risk cardiovascular patients.

METHODS

To determine the potential association between retinal vascular density on OCT-A and a comprehensive battery of hemodynamic variables in patients with myocardial infarction (MI) using data from the acute phase and at 3 months follow-up after cardiac rehabilitation. This prospective longitudinal study included patients who presented with MI in the cardiology intensive care unit at Dijon University Hospital. Main outcomes and measurements were retinal vessel density on OCT-A, hemodynamic status based on left ventricular ejection fraction (LVEF), and indexed cardiac output during the acute phase of myocardial infarction and at 3 months follow-up.

RESULTS

Overall, 30 patients were included in this pilot study. The median (IQR) age was 64 years (55-71) with 87% men. At admission, the mean (SD) LVEF was 53% (11), and the mean indexed cardiac output was 2.70 (0.83) L/min/m². On OCT-A, the mean inner retinal vascular density was 19.09 (2.80) mm^-1. No significant association was found between retinal vascular density and hemodynamic variables.

CONCLUSION

We found no significant association between retinal vascular density on OCT-A and hemodynamic variables in the acute phase of a myocardial infarction or after 3 months of cardiac rehabilitation. Therefore, OCT-A findings do not seem to be influenced by the hemodynamic changes associated with myocardial infarction.

Accuracy of the ISNT rule and its variants for differentiating glaucomatous from normal eyes in a population-based study

AIMS

To evaluate the accuracy of the ISNT rule (I=inferior, S=superior, N=nasal, T=temporal) and its variants with neuroretinal rim width and retinal nerve fibre layer (RNFL) thickness measurements differentiating normal from glaucomatous eyes.

METHODS

The diagnosis accuracy of the ISNT rule and its variants was evaluated in a population-based study. Neuroretinal rim widths were measured on monoscopic optic disc photographs with an image-processing program. RNFL thickness measurements were obtained with spectral-domain optical coherence tomography (SD-OCT).

RESULTS

In this study including 940 normal subjects and 93 patients with glaucoma, the sensitivity of the ISNT rule with optic disc photographs was 94.1% (95% CI 90.2 to 98.1), whereas its specificity was 49.2% (46.9 to 51.6). When using the IST rule, the sensitivity decreased to 69.9% (62.1 to 77.6) with a higher specificity, 87.0% (85.3 to 88.6). All the diagnosis indicators were somewhat lower for the different rules using RNFL thickness: the sensitivity of the ISNT rule was 79.4% (72.6 to 86.2) and its specificity was 34.1% (31.9 to 36.4). With the IST rule, the sensitivity decreased to 50.0% (41.6 to 58.4) while the specificity increased to 64.9% (62.7 to 67.2).

CONCLUSIONS

The ISNT and IST rules applied to neuroretinal rim width measurement by optic disc photographs are useful and simple tools for differentiating normal from glaucomatous eyes. The translation of these rules to RNFL thickness by SD-OCT is of limited value.

Subretinal Drusenoid Deposits in the Elderly in a Population-Based Study (the Montrachet Study)

Purpose

The aim of this study was to investigate the prevalence of subretinal drusenoid deposits (SDD) and to identify associated factors in an elderly population.

Methods

The participants of the population-based Montrachet study underwent an exhaustive ophthalmologic examination, including color fundus photography and macular spectral domain-optical coherence tomography (SD-OCT), coupled with infrared reflectance imaging. The presence of SDD and other age-related macular degeneration lesions, according to the European Eye Epidemiology SD-OCT classification of macular diseases, and subfoveal choroidal thickness were recorded. Moreover, the association of SDD and both clinical and demographic factors as well as plasma levels of vitamin E and lutein/zeaxanthin (L/Z) were analyzed.

Results

The mean age of patients was 82.3 ± 3.8 years and 62.7% were female. The prevalence of SDD was 18.1% (n = 205) in the subjects with at least one eye interpretable (n = 1135). In multivariate analysis, SDD was positively associated with increasing age (OR, 4.6; 95% CI, 2.8-7.7; P < 0.001 for subjects aged >85 years), female sex (OR, 1.7; 95% CI, 1.2-2.4; P = 0.005), and plasma L/Z level (OR, 1.2; 95% CI, 1.0-1.5; P = 0.039), and negatively associated with lipid-lowering drugs use (OR, 0.5; 95% CI, 0.3-0.9; P = 0.014 for statin medications) and subfoveal choroidal thickness (OR, 0.8; 95% CI, 0.7-0.9; P = 0.002).

Conclusions

The prevalence of SDD was high in subjects older than 75 years, more frequent in women, and was associated with a thinner choroid. The association with lipid-lowering drugs deserves further investigation.

Association of Acute Endophthalmitis With Intravitreal Injections of Corticosteroids or Anti-Vascular Growth Factor Agents in a Nationwide Study in France

Importance

The number of patients affected by retinal diseases treated with intravitreal injections (IVTs) has resulted in a rapidly growing number of procedures. One of the worst complications after these injections is endophthalmitis.

Objective

To evaluate the incidence of acute endophthalmitis after IVTs of corticosteroids or anti-vascular endothelial growth factor (anti-VEGF) agents.

Design, Setting, and Participants

This population-based cohort study included patients undergoing IVTs from January 1, 2012, through December 31, 2015, in France. Data were acquired from the French medical-administrative database (Système National d'Information Inter-Régime de l'Assurance Maladie), which collects hospitalization discharge abstracts and out-of-hospital care information for the whole country. Data were analyzed from March through July 2017.

Exposures

Intravitreal injections of corticosteroid or anti-VEGF agents.

Main Outcomes and Measures

Incidence of acute endophthalmitis within 6 weeks after IVT by means of billing codes from a national database.

Results

During the study period, 1 811 977 IVTs of corticosteroids or anti-VEGF agents performed on 254 927 patients (60.4% female; median age, 79 years [interquartile range, 70-85 years]) were analyzed. A total of 444 acute endophthalmitis cases (crude incidence, 0.0245%) were recorded. In multivariable analysis, which did not include adjustment for when the endophthalmitis occurred during the study period, the risk of endophthalmitis was lower in male patients (incidence rate ratio [IRR], 0.78; 95% CI, 0.63-0.96; P = .02), higher for corticosteroids than for anti-VEGF agents (IRR, 3.21; 95% CI, 2.33-4.44; P < .001), and higher for nonprefilled syringes of anti-VEGF medications than prefilled syringes for ranibizumab (IRR, 1.63; 95% CI, 1.15-2.30) and aflibercept (IRR, 1.82; 95% CI, 1.25-2.66; P < .001).

Conclusions and Relevance

The findings from this study of a nationwide database appear to have confirmed the low incidence rate of acute endophthalmitis after IVTs of corticosteroids or anti-VEGF agents. Although an association may not necessarily indicate a cause and effect, the risk for acute endophthalmitis after IVTs appeared to be higher for corticosteroids compared with anti-VEGF agents, while a lower risk of endophthalmitis appeared to be found with prefilled syringes of anti-VEGF medications.

Diagnostic accuracy of a calibrated abdominal compression to predict fluid responsiveness in children

BACKGROUND

Fluid administration to increase stroke volume index (SVi) is a cornerstone of haemodynamic resuscitation. We assessed the accuracy of SVi variation during a calibrated abdominal compression manoeuvre (ΔSVi-CAC) to predict fluid responsiveness in children.

METHODS

Patients younger than 8 yr with acute circulatory failure, regardless of their ventilation status, were selected. SVi, calculated as the average of five velocity-time integrals multiplied by the left ventricular outflow tract surface area, was recorded at four different steps: baseline, after an abdominal compression with a calibrated pressure of 25 mm Hg, after return to baseline, and then after a volume expansion (VE) of 10 ml kg^-1 lactated Ringer solution over 10 min. Patients were classified as responders if SVi variation after volume expansion (ΔSVi-VE) increased by at least 15%.

RESULTS

The 39 children included had a median [inter-quartile range (IQR)] age of 9 [5-31] months. Twenty patients were fluid responders and 19 were non-responders. ΔSVi-CAC correlated with ΔSVi-VE (r=0.829; P<0.001). The area under the receiver operating characteristic curve (ROC_AUC) was 0.94 [95% confidence interval (CI), 0.85-0.99]. The best threshold for ΔSVi-CAC was 11% with a specificity of 95% [95% CI, 84-100] and a sensitivity of 75% [95% CI, 55-95]. ROC_AUC of respiratory variation of IVC diameter (ΔIVC) was 0.53 [95% CI, 0.32-0.72].

CONCLUSION

ΔSVi-CAC during abdominal compression was a reliable method to predict fluid responsiveness in children with acute circulatory failure regardless of their ventilation status.

CLINICAL TRIALS REGISTRATION

CPP Lyon sud est II: n° ANSM 2015-A00388-41 Clinicaltrial.gov: NCT02505646.

Effect of In-Bed Leg Cycling and Electrical Stimulation of the Quadriceps on Global Muscle Strength in Critically Ill Adults: A Randomized Clinical Trial

IMPORTANCE

Early in-bed cycling and electrical muscle stimulation may improve the benefits of rehabilitation in patients in the intensive care unit (ICU).

OBJECTIVE

To investigate whether early in-bed leg cycling plus electrical stimulation of the quadriceps muscles added to standardized early rehabilitation would result in greater muscle strength at discharge from the ICU.

DESIGN, SETTING, AND PARTICIPANTS

Single-center, randomized clinical trial enrolling critically ill adult patients at 1 ICU within an 1100-bed hospital in France. Enrollment lasted from July 2014 to June 2016 and there was a 6-month follow-up, which ended on November 24, 2016.

INTERVENTIONS

Patients were randomized to early in-bed leg cycling plus electrical stimulation of the quadriceps muscles added to standardized early rehabilitation (n = 159) or standardized early rehabilitation alone (usual care) (n = 155).

MAIN OUTCOMES AND MEASURES

The primary outcome was muscle strength at discharge from the ICU assessed by physiotherapists blinded to treatment group using the Medical Research Council grading system (score range, 0-60 points; a higher score reflects better muscle strength; minimal clinically important difference of 4 points). Secondary outcomes at ICU discharge included the number of ventilator-free days and ICU Mobility Scale score (range, 0-10; a higher score reflects better walking capability). Functional autonomy and health-related quality of life were assessed at 6 months.

RESULTS

Among 314 randomized patients, 312 (mean age, 66 years; women, 36%; receiving mechanical ventilation at study inclusion, 78%) completed the study and were included in the analysis. The median global Medical Research Council score at ICU discharge was 48 (interquartile range [IQR], 29 to 58) in the intervention group and 51 (IQR, 37 to 58) in the usual care group (median difference, -3.0 [95% CI, -7.0 to 2.8]; P = .28). The ICU Mobility Scale score at ICU discharge was 6 (IQR, 3 to 9) in both groups (median difference, 0 [95% CI, -1 to 2]; P = .52). The median number of ventilator-free days at day 28 was 21 (IQR, 6 to 25) in the intervention group and 22 (IQR, 10 to 25) in the usual care group (median difference, 1 [95% CI, -2 to 3]; P = .24). Clinically significant events occurred during mobilization sessions in 7 patients (4.4%) in the intervention group and in 9 patients (5.8%) in the usual care group. There were no significant between-group differences in the outcomes assessed at 6 months.

CONCLUSIONS AND RELEVANCE

In this single-center randomized clinical trial involving patients admitted to the ICU, adding early in-bed leg cycling exercises and electrical stimulation of the quadriceps muscles to a standardized early rehabilitation program did not improve global muscle strength at discharge from the ICU.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02185989.

[Effectiveness of management of children with severe trauma in a pediatric trauma center and in an adult trauma center: A before-after study]

OBJECTIVE

To compare management of injured children in an adult trauma center (TC) with competencies in pediatric trauma care (2005-2007) and in a pediatric-only trauma center (2010-2012).

STUDY DESIGN

A before-after retrospective study.

PATIENTS AND METHODS

Fifty-nine children between 1 and 15 years of age admitted to the adult TC (2005-2007) were compared to 56 children admitted to the pediatric TC (2010-2012). Epidemiological data, severity scores, early outcome, and care duration in trauma resuscitation before whole-body CT were collected and compared between the two periods.

RESULTS

This study found no significant differences between the two periods in terms of care duration before the whole-body CT scan (28 min [18-40] vs 26.5 min [21-36], P=0.89) and early mortality (eight children [13.5%] vs ten children [17.8%], P=0.35).

CONCLUSION

With no differences in early management of injured children demonstrated, this study validates the organization within our pediatric trauma center. The effectiveness of management of children between 1 and 15 years of age with severe trauma seems to be similar in the two contexts.

Functional determinants of the Epstein-Barr virus protease

Herpesvirus proteases are essential for the production of progeny virus. They cleave the assembly protein that fills the immature capsid in order to make place for the viral DNA. The recombinant protease of the human gamma-herpesvirus Epstein-Barr virus (EBV) was expressed in Escherichia coli and purified. Circular dichroism indicated that the protein was properly folded with a secondary structure content similar to that of other herpesvirus proteases. Gel filtration and sedimentation analysis indicated a fast monomer-dimer equilibrium of the protease with a K(d) of about 60 microM. This value was not influenced by glycerol but was lowered to 1.7 microM in the presence of 0.5 M sodium citrate. We also developed an HPLC-based enzymatic assay using a 20 amino acid residue synthetic peptide substrate derived from one of the viral target sequences for the protease. We found that conditions that stabilised the dimer also led to a higher enzymatic activity. Through sequential deletion of amino acid residues from either side of the cleavage site, the minimal peptide substrate for the protease was determined as P5-P2'. This minimal sequence is shorter than that for other herpesvirus proteases. The implications of our findings are discussed with reference to the viral life-cycle. These results are the first ever published on the EBV protease and represent a first step towards the development of protease inhibitors.

In vitro dissection of the membrane and RNP binding activities of influenza virus M1 protein

Spontaneous proteolysis of influenza virus M1 protein during crystallisation has defined an N-terminal domain of amino acids 1--164. Full-length M1, the N-terminal domain, and the C-terminal part of M1 (residues 165--252) were produced in Escherichia coli. In vitro tests showed that only full-length M1 and its N-terminal domain bind to negatively charged liposomes and that only full-length M1 and its C-terminal part bind to RNP. However, only full-length M1 had transcription inhibition activity. Several independent experimental approaches indicate that in vitro transcription inhibition occurs through polymerisation/aggregation of M1 onto RNP, or of M1 onto M1 already bound to RNP, rather than by binding to a specific active site on the nucleoprotein or the polymerase. The structure/function of influenza virus M1 will be compared with that of the Ebola virus matrix protein, VP40.

Multidrug-resistant bacteria infection control: study of compliance with isolation precautions in a Paris university hospital

Isolation practices in a university hospital were analyzed for 137 patients with multidrug-resistant bacteria. Isolation was ordered in writing by physicians for 40% and instituted by nurses for 60%; 74% were isolated. Compliance depended on physician ordering in writing (odds ratio, 36.3; 95% confidence interval, 4.8-274.9). Nurses complied best with hand washing.

Combined results from solution studies on intact influenza virus M1 protein and from a new crystal form of its N-terminal domain show that M1 is an elongated monomer

The amino-terminal domain of influenza A virus matrix protein (residues 1-164) was crystallized at pH 7 into a new crystal form in space group P1. This packing of the protein implies that M1(1-164) was monomeric in solution when it crystallized. Otherwise, the structure of the M1 fragment in the pH 7 crystals was the same as the monomers in crystals formed at pH 4 where crystal packing resulted in dimer formation [B. Sha and M. Luo, 1997, Nature Struct. Biol. 4, 239-244]. Analysis of intact M1 protein, the N-terminal domain, and the remaining C-terminal fragment (residues 165-252) in solution also showed that the N-terminal domain was monomeric with the same dimensions as determined from the crystal structure. Intact M1 protein was also monomeric but with an elongated shape due to the presence of the C-terminal part. Circular dichroism showed that the C-terminal part of M1 contained helical structure. A model for soluble M1 is presented, based on the assumption that the C-terminal domain is spherical, in which the N- and C-terminal domains are connected by a linker sequence which is available for proteolytic attack.

Structure of the RNA inside the vesicular stomatitis virus nucleocapsid

The structure of the viral RNA (vRNA) inside intact nucleocapsids of vesicular stomatitis virus was studied by chemical probing experiments. Most of the Watson-Crick positions of the nucleotide bases of vRNA in intact virus and in nucleoprotein (N)-RNA template were accessible to the chemical probes and the phosphates were protected. This suggests that the nucleoprotein binds to the sugar-phosphate backbone of the RNA and leaves the Watson-Crick positions free for the transcription and replication activities of the viral RNA-dependent RNA polymerase. The same architecture has been proposed for the influenza virus nucleocapsids. However, about 5% of the nucleotide bases were found to be relatively nonreactive towards the chemical probes and some bases were hyperreactive. The pattern of reactivities was the same for RNA inside virus and for RNA in N-RNA template that was purified over a CsCl gradient and which had more than 94% of the polymerase and phosphoprotein molecules removed. All reactivities were more or less equal on naked vRNA. This suggests that the variations in reactivity towards the chemical probes are caused by the presence of the nucleoprotein.