Maher Saleh

Endophthalmitis After Intravitreal Injections: Incidence, Presentation, Management, and Visual Outcome

PURPOSE To report the incidence and characteristics of endophthalmitis after intravitreal injections of anti-vascular endothelial growth factor agents or corticosteroids and to describe the clinical and bacteriologic characteristics, management, and outcome of these eyes with acute endophthalmitis in France. DESIGN Retrospective, nationwide multicenter case series. METHODS From January 2, 2008 to June 30, 2013, a total of 316,576 intravitreal injections from 25 French ophthalmic centers were included. For each center, the number of intravitreal injections was determined using billing codes and the injection protocol was recorded. A registry and hospital records were reviewed to identify patients treated for endophthalmitis after injection during the same time period. The main outcome measures were the incidence of clinical endophthalmitis and visual acuity of endophthalmitis cases. RESULTS During the study period, 65 cases of presumed endophthalmitis were found, giving an overall incidence of 0.021% (2.1 in 10,000 injections) (95% confidence interval [CI], 0.016%-0.026%). The median number of days from injection to presentation was 4 [1-26] days. The most common symptom was vision loss. Bacterial identification was achieved in 43.4%. The most frequent pathogens were gram-positive bacteria (91.3%), including coagulase-negative Staphylococcus in 78.3%. Neither the interval between injection and presentation for endophthalmitis nor the clinical signs differentiated culture-positive from culture-negative cases. In multivariate analysis, the use of a disposable conjunctival mould assist device and the use of prophylaxis with an antibiotic or antiseptic were significantly associated with an increased incidence of endophthalmitis (P = .001). The majority of patients had worse visual acuity after 3 months of follow-up when compared with acuity before endophthalmitis. CONCLUSIONS The incidence of presumed endophthalmitis after intravitreal injections of anti-vascular endothelial growth factors or corticosteroids was low and the prognosis poor. Prevention and management remain challenging. It remains to be determined whether the findings of this study are relevant for other countries using different techniques for intravitreal injections.

Heavy chain-only antibodies and tetravalent bispecific antibody neutralizing Staphylococcus aureus leukotoxins

Panton–Valentine leukocidin (PVL) is a pore-forming toxin associated with current outbreaks of community-associated methicillin-resistant strains and implicated directly in the pathophysiology of Staphylococcus aureus-related diseases. Humanized heavy chain-only antibodies (HCAb) were generated against S. aureus PVL from immunized transgenic mice to neutralize toxin activity. The active form of PVL consists of the two components, LukS-PV and LukF-PV, which induce osmotic lysis following pore formation in host defense cells. One anti–LukS-PV HCAb, three anti–LukF-PV HCAbs with affinities in the nanomolar range, and one engineered tetravalent bispecific HCAb were tested in vitro and in vivo, and all prevented toxin binding and pore formation. Anti–LukS-PV HCAb also binds to γ-hemolysin C (HlgC) and inhibits HlgC/HlgB pore formation. Experiments in vivo in a toxin-induced rabbit endophthalmitis model showed that these HCAbs inhibit inflammatory reactions and tissue destruction, with the tetravalent bispecific HCAb performing best. Our findings show the therapeutic potential of HCAbs, and in particular, bispecific antibodies.

Choroidal thickness measurement in children using optical coherence tomography.

Purpose: To measure choroidal thickness (CT) in children of various ages by using spectral optical coherence tomography with enhanced depth imaging and to investigate the association between subfoveal CT and ocular axial length, age, gender, weight, and height in children. Methods: Healthy children were prospectively included between May and August 2012. Optical coherence tomography with the enhanced depth imaging system (Spectralis, Heidelberg, Germany) was used for choroidal imaging at nine defined points of the macula of both eyes. Axial length was measured using IOLMaster (Carl Zeiss Meditec, Dublin, CA). Height, weight, and refraction were recorded. Interobserver agreement in readings was also assessed by the Bland–Altman Method. Results: Three hundred and forty-eight eyes from 174 children aged 3.5 years to 14.9 years were imaged. The mean subfoveal CT in right eyes was 341.96 ± 74.7 µm. Choroidal thickness increased with age (r = 0.24, P = 0.017), height, and weight but not with gender (P > 0.05). It was also inversely correlated to the axial length (r = 0.24, P = 0.001). The nasal choroid appeared thinner than in the temporal area (analysis of variance, P < 0.0001). Conclusion: In children, CT increases with age and is inversely correlated to axial length. There is a significant variation of CT between children of the same age.

Long-term outcomes of acute traumatic maculopathy.

Purpose: To report immediate and long-term outcomes of acute traumatic maculopathy. Methods: Retrospective case series. Acute traumatic maculopathy was defined as a macular opacification after blunt trauma. Patients were examined at presentation, 1 week, and 6 months. Retinography and time-domain and spectral-domain optical coherence tomographies were performed in all patients. Central macular thickness, the qualitative aspect of the macular profile, and retinal nerve fiber layer thickness were assessed. Multifocal electroretinography was performed at presentation and after 6 months. Results: Twenty patients (20 eyes) were studied. Their mean age was 20.8 years, and the initial visual acuity was 20/100. In all cases, initial optical coherence tomographies revealed an increase in reflectivity of the inner and outer segment junction, with an apposition of the latter to the retinal pigment epithelium. Optical coherence tomography profiles were back to normal at the 1-week visit. Initial multifocal electroretinography performed in six patients showed a decrease in amplitudes in the central area but not in the periphery. There was no delay in latency. Similar electroretinal dysfunction persisted after 6 months. Conclusion: Macular opacification observed in acute traumatic maculopathy is associated with an increase in reflectivity of the inner and outer segment photoreceptor junction on optical coherence tomography. Although visual recovery is excellent, reduction in the electroretinal activity observed 6 months after the trauma suggests that the retina does not fully recover from the initial disorganization of its external layers.

Use of digital camera imaging of eye fundus for telemedicine in children suspected of abusive head injury

Aim: Pilot study of the role of RetCam imaging for telemedicine in lieu of availability of ophthalmologist examination for cases of suspected abusive head injury. Design: Cross-sectional observational study. Participants: 21 children admitted in the paediatric units of the University Hospital of Strasbourg (France) with suspicion of abusive head trauma were included. Methods: Children were examined by standard ophthalmoscopy. Photographs were taken using the RetCam-120 Digital Retinal Camera. Eye fundus images were stored and remotely read by an ophthalmologist. Patients also had radiographic skeletal series to look for bone fractures, and CT scan and/or MRI of the head to look for intracranial haemorrhages. Main outcome measures: The absence or presence of retinal haemorrhages was assessed by both methods. Feasability, sensitivity and specificity of the digital camera procedure were determined. Results: 85.7% of the children presented cerebral bleeding, and 14 out of the 21 (66.7%) had retinal haemorrhages on ophthalmoscopy. The digital camera detected the retinal abnormalities in all cases. One false-positive case was also reported. The sensitivity of the digital camera detection method was 100% with a specificity of 85.7%. 14 patients were eventually diagnosed as suffering from abusive trauma. RetCam helped establishing the diagnosis of abuse in 92.8% of these cases. Conclusions: Digital photography compared with ophthalmoscopy has a good sensitivity and specificity in detecting retinal haemorrhages. Remote reading of RetCam-120 photographs could be a promising strategy in detecting children with abusive head trauma.

p-Sulfonato-calix(n)arenes inhibit staphylococcal bicomponent leukotoxins by supramolecular interactions

PVL (Panton-Valentine leukocidin) and other Staphylococcus aureus β-stranded pore-forming toxins are important virulence factors involved in various pathologies that are often necrotizing. The present study characterized leukotoxin inhibition by selected SCns (p-sulfonato-calix[n]arenes): SC4, SC6 and SC8. These chemicals have no toxic effects on human erythrocytes or neutrophils, and some are able to inhibit both the activity of and the cell lysis by leukotoxins in a dose-dependent manner. Depending on the type of leukotoxins and SCns, flow cytometry revealed IC50 values of 6-22 μM for Ca2+ activation and of 2-50 μM for cell lysis. SCns were observed to affect membrane binding of class S proteins responsible for cell specificity. Electrospray MS and surface plasmon resonance established supramolecular interactions (1:1 stoichiometry) between SCns and class S proteins in solution, but not class F proteins. The membrane-binding affinity of S proteins was Kd=0.07-6.2 nM. The binding ability was completely abolished by SCns at different concentrations according to the number of benzenes (30-300 μM; SC8>SC6≫SC4). The inhibitory properties of SCns were also observed in vivo in a rabbit model of PVL-induced endophthalmitis. These calixarenes may represent new therapeutic avenues aimed at minimizing inflammatory reactions and necrosis due to certain virulence factors.

Repeated IL-10 measurement in aqueous humor and OCT imaging are valuable tools to monitor intraocular lymphoma treated with intravitreal injections of methotrexate

IntroductionPrimary intraocular lymphoma (PIOL) is a rare disease(1/100,000) whose incidence has been increasing in the past2decades[1]. The survival prognosis of PIOL remainsreserved due to frequent disease extension to the CNS within3years[2]. Systemic chemotherapies such as intravenousmethotrexate (MTX) are the classical first-line treatment [3].However, the systemic route of administration is related toserious haematological side-effects, especially because highdoses are necessary to reach efficient vitreous concentrations(>0.5 μmol/l) [4]. In order to overcome these drawbacks,intravitreal MTX injections have been proposed in cases ofisolated PIOL with successful outcomes and acceptabletolerance [5]. Nevertheless, the optimal follow-up schemefor this treatment option remains to be defined [6]. In thepresent study, we report the cases of two patients treated withintravitreal injections of MTX with a 1-year follow-up.Pharmacokinetics of ocular MTX were assessed by MTXmeasurements in aqueous humor. Long-term efficacy wasmonitored by monthly IL-10 measurements and opticalcoherence tomography (OCT) examinations. Serial IL-10measurements combined with OCTexaminations enabled theearly detection of a PIOL recurrence.MethodsPatient 1An 82-year-old woman was diagnosed with an ocularnon-Hodgkin lymphoma in the right eye. The initialvisual acuity (VA) was counting fingers (CF). OCTdisplayed multiple detachments of the retinal pigmentepithelium (PED). A vitreal biopsy established thediagnosis of B-cell PIOL. Staging was negative. Locore-gional radiotherapy (30 Gy), combined with six chemo-therapeutic treatments (rituximab, cyclophosphamide,vincristine, and prednisolone) were performed. However,PIOL recurred at the end of the treatment. An episode offever and severe confusion contraindicated anotherchemotherapy cycle.Patient 2A 75-year-old woman presented with an unilateral PIOL inthe right eye, with no extra-ocular involvement. VA wasdecreased to 20/400. Vitrectomy revealed B-cell lymphomawith clonal Ig kappa rearrangement.In both cases, MTX injections were proposed ac-cording to the same therapeutic regimen [7]. Briefly,400 μg/0.1 ml of MTX were injected into the vitreoustwice per week for 1 month, followed by weeklyinjections for 1 month, and then by monthly maintenanceinjections.Before each injection, 200 μl of aqueous humor werewithdrawn, of which half was used to determine the

Ocular penetration of topically applied linezolid in a rabbit model.

PURPOSE: To evaluate ocular penetration of topically applied linezolid, a new antibiotic agent targeted against gram‐positive organisms. SETTING: Laboratory of Pharmacology, University Hospital of Strasbourg, Strasbourg, France. METHODS: New Zealand White rabbits were divided into 3 equal groups. One drop of 50 μL (2 mg/mL) linezolid was administrated in Group 1. In Group 2, eyes were dosed in accordance with a keratitis protocol (1 drop of 2 mg/mL every 15 minutes for 1 hour). Aqueous humor was sampled 6 times from immediately after to 3 hours after drop delivery. In Group 3, a keratitis protocol was implemented before the animals were humanely killed. Conjunctiva, cornea, vitreous, and blood samples were collected 1 hour and 2 hours after the last drop. Linezolid concentrations were measured by high‐performance liquid chromatography. RESULTS: Each group comprised 8 rabbits. In Group 1 and Group 2, the peak linezolid concentration in the aqueous humor (mean 0.87 mg/L ± 0.16 [SD] and 2.17 ± 0.4 mg/L, respectively) was 45 minutes after the last drop delivery. In Group 3, the concentrations 1 hour and 2 hours after the last drop were higher than 3 μg/g in the conjunctiva samples and higher than 4 μg/g in the cornea samples. The linezolid concentration in the vitreous and serum was negligible. CONCLUSIONS: Linezolid levels in the aqueous humor, conjunctiva, and cornea exceeded the minimum inhibitory concentration of most gram‐positive organisms that cause bacterial keratitis and endophthalmitis. Linezolid could be a valuable alternative in cases of increased resistance to vancomycin. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Bilateral macular ischemia and severe visual loss following trastuzumab therapy

Fo r pe rs on al u se o nl y. Trastuzumab (Herceptin, Genentech Inc) is a monoclonal antibody interfering with human epidermal growth factor receptor 2, which is currently used for the treatment of breast cancer [1] and metastatic gastric cancer [2]. We report a case of bilateral ischemic maculopathy following intravenous therapy of trastuzumab in a 50-year-old woman. She had breast cancer with cerebral and pulmonary metastases and had been treated with combined cerebral radiotherapy and docetaxel therapy without visual side effects, as confi rmed by a normal ophthalmologic examination performed at the time. Trastuzumab (2 mg/kg) was introduced six months after this fi rst-line radiochemotherapy regimen. Three months later, she presented with severe bilateral visual loss: visual acuity (VA) was 20/100 and 20/200 (right eye and left eye, respectively). On funduscopy, macular edema, hemorrhages, and hard exudates were noted in both eyes (Figure 1A), while the retinae beyond the vascular arcades were normal. On fl uorescein angiography (FA), the foveal avascular zone was enlarged in both eyes (Figure 1B). Leakage from the unperfused foveolar capillaries and cystoid macular edema were also present (Figure 1B). Optical coherence tomography (OCT) examination showed bilateral cystic changes and shallow central serous retinal detachment (Figure 1C). Central macular thickness (CMT) was measured at 546 μ m and 332 μ m in the right and left eyes, respectively. VA worsened and CMT increased under trastuzumab treatment. As a consequence, trastuzumab was discontinued for three months. No progression was observed. One month after its reintroduction, vision decreased again (20/300, 20/400),

Les facteurs de virulence de Staphylococcus aureus

Resume La bacterie Staphylococcus aureus est responsable de nombreux types d’infections chez l’homme et compte parmi les agents pathogenes les plus souvent isoles des infections hospitalieres et communautaires. Outre les nombreuses resistances que cette bacterie peut presenter vis-a-vis des antibiotiques et des antiseptiques, il peut etre etonnant de constater combien cette derniere est egalement armee pour annihiler bon nombre des defenses que son hote pourrait lui opposer. C’est en fait une veritable ingenierie dont dispose S. aureus pour repondre aux perils d’un hote hostile qui lui oppose anticorps, phagocytose ou cytotoxicite. L’emergence de souches particulierement virulentes dans la communaute illustre le brassage genetique de ces dernieres via l’homme et ses activites. Ces parades se distribuent en plusieurs groupes de toxines distinctes aux activites cytolytiques, proteolytiques, superantigeniques ou ADP-ribosylantes. Le plus souvent, chaque groupe de toxines contient plusieurs serotypes, ce qui pourrait permettre a la bacterie d’echapper aux premieres lignes de defense de l’hote. Cette revue propose une description des toxines secretees par S. aureus et tente d’illustrer leur complementarite.