Fabrication of Plane Optical Mosaics Imitating Human Corneal Endothelium

International audienc

Fabrication of optical mosaics mimicking human corneal endothelium for the training and assessment of eye bank technicians

International audienceThe determination of endothelial cell density (ECD) is a crucial activity in eye banks for the assessment of corneal tissue quality. These cells are responsible for corneal transparency, and ECD correlates with graft survival. ECD is mainly assessed with a manual "naked-eye" procedure under a transmitted light microscope in Europe and using a specular microscope in the United States. Interbank and intrabank variability has been previously demonstrated. In order to facilitate training and continuing education of technicians and reliability assessment of eye banks' ECD determination, we use micro-optics technologies to fabricate test mosaics that exactly reproduce the image of human corneal endothelium. The description of the fabrication process is detailed, and comparisons are made between amplitude and phase mosaics

Florilège des indications d antiVEGF en ophtalmologie (de la rétine à la cornée. Illustration de deux complications sévères des injections intravitréennes et implication médico-légale)

Depuis quelques années, l utilisation des antiVEGF a augmenté de manière considérable. Après avoir démontré leur efficacité dans la dégénérescence maculaire liée à l âge, ils ont révolutionné la pratique de l ophtalmologie. Après avoir rappelé l origine pharmacologique de ces thérapeutiques, nous décrivons dans une deuxième partie les grandes études à fort niveau de preuve ayant mené à l obtention de l AMM dans diverses indications concernant le segment postérieur. Dans une troisième partie, nous détaillons les possibilités d utilisation de ces antiVEGF dans les indications de néovascularisation irienne. A l heure actuelle, les autres indications du segment antérieur n ont fait l objet que d études à faibles niveaux de preuve, mais ouvrent la voie à de futurs essais comparatifs randomisés. Enfin, nous illustrons par la description de deux cas cliniques issus de notre CHU deux complications sévères des injections intravitréennes et leur implication médico-légale. L essor considérable de ces nouveaux traitements a contribué à améliorer la prise en charge et la qualité de vie des patients dans ces pathologies aux évolutions classiquement péjoratives. Cependant, il existe des limites à ne pas négliger : leur durée d action limitée induit des réinjections fréquentes coûteuses pour la santé publique et risquées pour les patients. Il semble donc nécessaire de poursuivre les efforts de recherche dans la thérapeutique de ces pathologies.ST ETIENNE-BU Médecine (422182102) / SudocSudocFranceF

Baseline factors predictive of visual prognosis in acute postoperative bacterial endophthalmitis in patients undergoing cataract surger

IMPORTANCE Although rare, postoperative endophthalmitis in patients undergoing cataract surgery can lead to anatomical or functional loss of the eye. Therapeutic strategies such as antibiotic prophylaxis and microbiological diagnosis are more effective with a target patient population. New prospective data are needed to identify prognostic factors. OBJECTIVE To identify baseline factors of visual prognosis in patients with acute bacterial endophthalmitis after cataract surgery. DESIGN Prospective study of consecutive patients undergoing cataract surgery, enrolled from March 1, 2004, through December 31, 2005. We analyzed outcomes to determine the effect on the final visual outcome, defined as poor (visual acuity [VA] worse than 20/100) or good (VA 20/40 or better) using univariate and multivariate analysis. SETTING Four academic hospitals. PARTICIPANTS Ninety-nine consecutive patients with cataract. INTERVENTION Corneal phacoemulsification. MAIN OUTCOMES AND MEASURES Factors related to the cataract surgery (complications), initial clinical presentation, and microbiological diagnosis and the final VA. RESULTS The significant baseline factors (at presentation) for good visual outcome (45% of the series) were the winter season, absence of complications during cataract surgery, initial VA, microbiological investigations revealing no microorganism or a coagulase-negative Staphylococcus species (CNSP), and fundus visibility. Quantitative factors associated with a good clinical prognosis were shorter duration of cataract surgery, younger age, and a hypopyon no greater than 1.5 mm. Significant factors associated with poor visual outcome were infection of the right eye, initial VA, corneal edema, a hypopyon larger than 1.5 mm, detection of bacterial species other than a CNSP, and the absence of fundus visibility. Multiple logistic regression analysis showed that high bacterial virulence was the only independent factor (odds ratio, 14.0 [95% CI, 2.7-71.0]; P = .001) for poor visual outcome. On the other hand, low bacterial virulence (odds ratio, 0.2 [95% CI, 0.03-0.6]; P = .01) and the absence of complications during cataract surgery (0.1 [0.01-0.4]; P = .003) were independent factors for good VA. CONCLUSIONS AND RELEVANCE Most clinical outcome factors in acute postoperative endophthalmitis can be identified at presentation. The bacterial virulence level is the main factor predictive of the final visual prognosis

Delivery of molecules into corneal endothelium using nanoparticles activated by femtosecond laser pulses: proof of concept

International audiencePurpose NanoFemtoTransfection (NFT) is an innovative and promising non-viral technique to transfer molecules into cells (Chakravarty. Nature Nanotechnology 2010;5:607). It consists in temporarily permeabilizing cell membrane by a photoacoustic effect obtained by nanoparticles of black carbon activated by Ti-Saphir femtosecond laser (fsL) pulses. Calcein (622 Da), tagged bovine serum albumine (70 kDa) and one eGFP plasmid (5 MDa) were transfected into two non-adherent cell lines (DU145 prostate-cancer and GS-9L rat gliosarcoma). Our aim was to adapt the NFT to adherent human corneal endothelial cells (HCEC

Corneal perforation: another side effect of nicorandil

8siCONTEXT: Nicorandil is an antianginal drug used for 20 years in Japan and introduced in France in 1994. Since 1997, side effects such as mucocutaneous ulcerations have regularly been reported. OBJECTIVE: To describe the first case of a patient with a spontaneous corneal perforation associated with mucocutaneous ulcerations while taking Nicorandil. MATERIALS AND METHODS: A 81-year-old patient, with no past history of ocular disease but a long past history of cardiovascular disease, presented with a spontaneous paracentral corneal perforation. This was consecutive to 5 months of recurrent keratoconjunctivitis and mucocutaneous ulcerations resistant to conventional therapy. (He was taking nicorandil for 5 years.) A penetrating keratoplasty was performed in emergency. RESULTS: Inflammatory and infectious causes of spontaneous corneal perforation were ruled out. After initial uneventful post-operative wound healing, an epithelial ulcer appeared on the graft. Dermatologists suggested the iatrogenic role of nicorandil and the drug was discontinued. Both mucocutaneous and corneal ulcerations resolved rapidly. DISCUSSION: Although mucocutaneous ulcerations have been attributed several times to nicorandil, this is, to our knowledge, the first major corneal damage due to this antianginal drug. Timing, pattern of illness, absence of other aetiology, recurrence of epithelial ulceration on the corneal graft and its spontaneous healing after nicorandil discontinuation make it highly apparent probable that nicorandil was directly involved in this corneal perforation. CONCLUSION: Ophthalmologists and dermatologists should be aware of the risk of severe but reversible corneal ulcerations in patients treated with nicorandil. A pharmacovigilance warning statement should be compulsory.nonenoneCampolmi, Nelly; Guy, Claire; Cinotti, Elisa; Forest, Fabien; Gain, Philippe; Philippe-Zech, Camille; Gauthier, Anne Sophie; Thuret, GillesCampolmi, Nelly; Guy, Claire; Cinotti, Elisa; Forest, Fabien; Gain, Philippe; Philippe Zech, Camille; Gauthier, Anne Sophie; Thuret, Gille

Baseline predictive factors of visual prognosis in acute bacterial postcataract endophthalmitis

National audienceAbstract: Purpose To identify baseline clinical factors of visual prognosis in patients with acute endophthalmitis following cataract surgery. Methods: 99 patients of four academic hospitals (FRIENDS group). Factors were analyzed based on the final visual outcome, defined as poor (<20/100) or good (≥20/40) using univariate and multivariate analysis Results: Multiple logistic regression analysis showed that high bacterial virulence was the only independent factor (odds ratio [OR]= 14, 95% confidence interval [CI]: 2.7–71, p=0.001) for poor visual outcome. On the other hand, low bacterial virulence (OR=0.1 95%CI: 0.03–0.6, p=0.01) and the absence of complications (OR=0.07, 95%CI: 0.01–0.4, p=0.003) during cataract surgery were independent factors for good VA. Conclusion: Visual outcome factors in acute postcataract endophthalmitis identified in this prospective study (2004–2007) were similar to those reported by the EVS 10 years ago. The bacterial virulence level was the main predictive factor of final visual prognosis. This emphasizes the need for rapid bacterial identification and characterization using new biomolecular tools

Improvement of delivery of molecules into corneal endothelium using nanoparticles activated by femtosecond laser pulses

International audiencePurpose NanoFemtoTransfection (NFT) is an innovative and promising technique of gene transfer (Nature nanotechnology 2011). It consists in permeabilizing cell membrane with nanoparticles (NP) of black carbon activated by Ti-Sapphire femtosecond laser (FsL) in order to safely introduce molecule of interest. Initially described for cell suspension, we adapted during last year NFT to human corneal endothelial cells (EC) Aim: to further optimize NFT of EC in vitroMethods The model of NFT of calcein (a small molecule) in an EC line (B4G12, DMSZ, Germany) was used to optimize exposition times, fluence and Ti-Saphir FsL beam movements in order to determine the best efficiency/toxicity ratio. Calcein transfer was observed with fluorescent microscopy (IX81, Olympus) and quantified by flow cytometry (FACSCalibur, BD, CA). Viability of EC was assessed by propidium iodide staining. Staining of actine with phalloidin and immunostaining of ZO-1 was performed to study cell alteration caused by NFTResults With a static laser beam increasing FsL fluence and exposure time increased transfection efficiency but also EC mortality. The use of mobile FsL beam (with a XY micrometric stage, cheaper than a scanner), permitted an irradiation of the entire area of EC culture resulting in a noticeably increased efficiency that reached 38% of transfected EC and a limited toxicity (3%). Calcein positive EC presented the same phalloidin and ZO-1 patterns as control ECConclusion Optimized NFT parameters are currently being tested in our laboratory to transfect plasmids. Grants: Fondation pour la Recherche Médicale, Fondation des Aveugles de Franc