A light-sensitive, externally powered microchip was surgically implanted subretinally near the macular region of volunteers blind from hereditary retinal dystrophy. The implant contains an array of 1500 active microphotodiodes (‘chip’), each with its own amplifier and local stimulation electrode. At the implant's tip, another array of 16 wire-connected electrodes allows light-independent direct stimulation and testing of the neuron–electrode interface. Visual scenes are projected naturally through the eye's lens onto the chip under the transparent retina. The chip generates a corresponding pattern of 38 × 40 pixels, each releasing light-intensity-dependent electric stimulation pulses. Subsequently, three previously blind persons could locate bright objects on a dark table, two of whom could discern grating patterns. One of these patients was able to correctly describe and name objects like a fork or knife on a table, geometric patterns, different kinds of fruit and discern shades of grey with only 15 per cent contrast. Without a training period, the regained visual functions enabled him to localize and approach persons in a room freely and to read large letters as complete words after several years of blindness. These results demonstrate for the first time that subretinal micro-electrode arrays with 1500 photodiodes can create detailed meaningful visual perception in previously blind individuals.

Vitreoretinal diffuse large B-cell lymphoma is a rare disorder, occurring as primary ocular disease or as secondary involvement by primary central nervous system lymphoma. It is usually diagnosed by cytologic, immunocytochemical, and molecular examination of vitreous aspirates. However, distinguishing vitreoretinal diffuse large B-cell lymphoma from uveitis remains difficult, and clonality analysis may be either unsuccessful or misleading. Diffuse large B-cell lymphoma arising in immune-privileged sites (eg, the central nervous system) shows a high frequency of MYD88 mutations. Therefore, we retrospectively assessed the frequency of MYD88 mutations in vitreoretinal lymphoma (VRL) and their diagnostic potential in 75 vitrectomy samples of 69 patients, and validated our results in a separate cohort (n = 21). MYD88 mutations were identified in 20 of 29 (69%) clinically, histologically, and molecularly confirmed VRL, including 6 cases of the test cohort initially diagnosed as reactive (3/6) or suspicious (3/6) for lymphoma. MYD88 mutations, especially L265P, are very frequent in VRL and their detection significantly improves the diagnostic yield of vitrectomy specimens.

Subretinal electric stimulation can yield reliable, predictable percepts. Patterned perception is feasible, enabling blind persons to recognize shapes and discriminate different letters. Stimulation paradigms must be optimized, to further increase spatial resolution, demanding a better understanding of physical and biological effects of single versus repetitive stimulation (ClinicalTrials.gov number, NCT00515814).

Purpose: That vascular endothelial growth factor (VEGF) plays a major role in inflammatory angiogenesis has been well established. This pilot study was designed to evaluate experimental treatment with bevacizumab eyedrops in corneal neovas-cularization induced by alkali burn. The feasibility of topical administration, cor-neal cell viability and corneal penetration were investigated in an animal model. Methods: Eighteen chinchilla bastard rabbit corneas injured with 1 m NaOH were divided into three groups: untreated, early and late treatment groups. Eyedrops of bevacizumab solution (25 mg ⁄ ml) were administered five times daily. Clinical examination under stereoscopic microscope was performed to evaluate corneal opacity, neovascularization, vessel size and oedema. Histopathology was analysed for vessel density and apoptotic reaction. Additionally, intracameral bevacizumab concentration was measured with enzyme-linked immunosorbent assay (ELISA) after repeated topical applications. Results: A fast increase in aqueous bevacizumab concentration was achieved when the solution was instilled every minute onto a healthy eye surface. As well as clear anti-angiogenic effects, anti-fibrotic effects were also seen after corneal burn, maintaining corneal transparency. Early treatment of actively growing vessels showed a significantly better outcome, although apoptosis of pre-existing vessels could also be induced by the late treatment. No specific toxicity was seen regarding epithelium, keratocytes or endothelium. Conclusions: The data from this pilot study suggest that bevacizumab eyedrops can sufficiently penetrate the corneal stroma and anterior chamber. When administered soon after alkali burn, bevacizumab seems to significantly reduce corneal damage. Combinations of established treatment regimens with topical bevacizumab might be considered in severe injuries with otherwise devastating prognoses.

The presented Z-suture is a simple, rapid and safe knotless technique that facilitates transscleral suture fixation of various intraocular implants in the ciliary sulcus like sutured intraocular lenses, artificial iris prostheses, and iris diaphragms. As the knotless approach reliably avoids suture erosion, external fixation can be performed without any protecting scleral flaps or lamellar grooves. The needle is simply passed through the sulcus, and the emerging polypropylene suture is secured in the sclera using a zigzag shaped intrascleral suture (Zsuture). Each pass starts directly adjacent to the exiting site. Five passes are sufficient to reliably fix the suture resisting even maximum tractive forces. Once this procedure is done, the suture can be cut without any knot. By avoiding suture knots, and hence the necessity for intrascleral flaps, this knotless approach may help to reduce suture-related complications such as scleral atrophy, suture erosion and infections.

Aim: To evaluate the antiproliferative and cytotoxic properties of bevacizumab, a monoclonal antibody against vascular endothelial growth factor (VEGF), on human retinal pigment epithelium (ARPE19) cells, rat retinal ganglion cells (RGC5), and pig choroidal endothelial cells (CEC). Methods: Monolayer cultures of ARPE19, RGC5, and CEC were used. Bevacizumab (0.008-2.5 mg/ml), diluted in culture medium, was added to cells that were growing on cell culture dishes. Cellular proliferative activity was monitored by 59-bromo-29-deoxyuridine (BrdU) incorporation into cellular DNA and the morphology assessed microscopically. For cytotoxicity assays ARPE19, RGC5, and CEC cells were grown to confluence and then cultured in a serum depleted medium to ensure a static milieu. The MTT test was performed after 1 day. The ''Live/Dead'' viability/cytotoxicity assay was performed and analysed by fluorescence microscopy after 6,12,18,24, 30, 36, and 48 hours of incubation. Expression of VEGF, VEGF receptors (VEGFR1 and VEGFR2) and von Willebrand factor was analysed by immunohistochemistry. Results: No cytotoxicity of bevacizumab on RGC5, CEC, and ARPE19 cells could be observed after 1 day. However, after 2 days at a bevacizumab concentration of 2.5 mg/ml a moderate decrease in ARPE19 cell numbers and cell viability was observed. Bevacizumab caused a dose dependent suppression of DNA synthesis in CEC as a result of a moderate antiproliferative activity (maximum reduction 36.8%). No relevant antiproliferative effect of bevacizumab on RGC5 and ARPE19 cells could be observed when used at a concentration of 0.8 mg/ml or lower. CEC and ARPE 19 cells stained positively for VEGF, VEGFR1, and VEGFR2. More than 95% of the CEC were positive for von Willebrand factor. Conclusions: These experimental findings support the safety of intravitreal bevacizumab when used at the currently applied concentration of about 0.25 mg/ml. Bevacizumab exerts a moderate growth inhibition on CEC when used in concentrations of at least 0.025 mg/ml. However, at higher doses (2.5 mg/ml) bevacizumab may be harmful to the retinal pigment epithelium.

. Purpose:  To evaluate the potential use of decellularized porcine corneas (DPCs) as a carrier matrix for cultivating human corneal cells in tissue engineering. Methods:  Corneal cells were isolated from human corneoscleral rims. Porcine corneas were decellularized using hypotonic tris buffer, ethylene diamine tetra‐acetic acid (EDTA, 0.1%), aprotinin (10 KIU/ml) and 0.3% sodium dodecyl sulphate. Haematoxylin–eosin (HE) and 4,6‐diamidino‐2‐phenylindole (DAPI) staining were performed to confirm removal of the corneal cells. Quantitative analysis was performed to determine levels of desoxyribonucleic acid (DNA) using DNA Purification Kit (Fermentas, St. Leon‐Rot, Germany). Alcian blue staining was carried out to analyse the structure of the extracellular matrix (ECM). Corneal stromal cells were injected into the DPCs; limbal corneal epithelial cells and corneal endothelial cells were seeded onto the anterior and posterior surfaces of the DPCs, respectively. Evaluation was undertaken at days 14 and 30. The phenotypical properties of the cultivated corneal cells were investigated using Immunolocalization of type I collagen, keratocan, lumican, cytokeratin 3 (AE5) and type VIII collagen. Results:  Haematoxylin–eosin and DAPI staining showed efficient elimination of porcine corneal cells, whereas alcian blue confirmed gross preservation of the ECM. The quantitative analysis of the DNA content showed a significant reduction (mean before decellularization: 75.45 ± 13.71 ng/mg; mean after decellularization: 9.87 ± 2.04 ng/mg, p < 0.001). All three types of corneal cells were efficiently cultured and expanded on the DPCs. Conclusions:  Decellularized porcine corneas might serve as a potential scaffold for tissue engineering of the cornea, possibly providing xenogenic substrate for corneal transplantation.

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