electrochemotherapy-3d-ocular-melanoma-spheroids-using-customized

Electrochemotherapy in 3D Ocular Melanoma Spheroids using a Customized Electrode

Electrochemotherapy (ECT) is the combination of transient pore formation following electric pulse application with the administration of cytotoxic drugs, ...

Martin-Luther University Halle-Wittenberg

Ocular trauma can lead to severe visual impairment and morbidity, depending on the anatomical structures affected. The main causes of ocular trauma include foreign bodies, impact by an object, falls, and chemicals. Most ocular traumas occur in children or young male adults. A meticulous slit lamp examination is crucial for assessing all anatomical structures. Trauma to the crystalline lens can result in dislocation, an intralenticular foreign body, cataract, fragmentation, and capsular breach. An intraocular lens (IOL) can endure subluxation or luxation under the conjunctiva, into the anterior chamber or the vitreous, or can be extruded. The surgical approach depends on the condition and morphology of the lens and the anatomical structures surrounding it. If there is capsular bag support, a secondary IOL can be placed in the sulcus using remnants of the damaged capsule. If there is no capsular bag support, a secondary IOL can be fixated to the anterior chamber angle, to the iris, or to the sclera. A detailed history of injury cannot always be obtained in trauma settings. Proper education, supervision, and certified safety eye protectors could prevent up to 90% of ocular injuries. Lens trauma can be treated with various surgical procedures and fixation techniques, which nevertheless require advanced surgical skills owing to the fine anatomical structure of the anterior segment. A careful surgical strategy should be established for a globe reconstruction after trauma with secondary lens implantation. Clin. Anat. 31:6-15, 2018. © 2017 Wiley Periodicals, Inc.

Methods of fixation of intraocular lenses according to the anatomical structures in trauma eyes.

Corneal burn grade IV usually leads to blindness. Several different surgical techniques remain challenging owing to the extensive tissue damage. Here, we introduce a novel technique with a 15 mm corneoscleral and limbal homologous graft combined with sequential autologous corneal removal ab interno, with a vitrectomy probe to save the anterior chamber angle. In vivo anatomy with optical coherence tomography is the surgical key. A large 15 mm sclerocorneal graft is sutured on top of the remainder of the destroyed cornea and sclera after removal of the epithelium and conjunctiva, with anterior synechiolysis if necessary, peripheral iridectomy and conjunctivoplasty. The recipient central corneal stroma is not removed, primarily to protect the anterior chamber angle. After three weeks, the collagenolytic central recipient corneal stroma can be removed with a small 23 g vitrectomy probe, respecting the lens and scleral spur. The corneoscleral graft remains clear under systemic and local immunosuppression. Intraocular pressure is well controlled because the anterior chamber angle is respected. Recurrent corneal erosions need close follow-up. Therapeutic soft contact lenses can support topical therapy. In cases of sclercorneal graft decompensation or rejection after 3-5 years, a new sclerocorneal graft (with limbal donation) seems to be superior to perforating keratoplasty without limbal stem cell transplantation. Repeated sclerocorneal grafts after severe corneal burn with limbal transplantation and maintenance of the complete anterior angle structure are a successful option for preventing blindness and achieving good visual acuity. Clin. Anat. 31:39-42, 2018. © 2017 Wiley Periodicals, Inc.

Sclerocorneal graft and sequential removal of melted cornea after severe corneal burn with perforation.

Acanthameoba keratitis is a serious ophthalmological condition with a potentially vision-threatening prognosis. Early diagnosis and recognition of relapse, and the detection of persistent Acanthamoeba cysts, are essential for informing the prognosis and managing the condition. We suggest the use of in vivo confocal microscopy not only to identify the early signs of relapse after keratoplasty in patients with Acanthamoeba keratitis, but also as an additional follow-up tool after antimicrobial crosslinking. This study shows that in vivo confocal microscopy is, in experienced hands, a quick and reliable diagnostic tool. Clin. Anat. 31:60-63, 2018. © 2017 Wiley Periodicals, Inc.

Confocal microscopy as an early relapse marker for acanthamoeba keratitis.

A traumatic wound dehiscence can occur many years after surgery in 2-6% of all keratoplasties. Intraocular tissue prolapse can lead to severe visual loss. Deep anterior lamellar keratoplasty (DALK) leads to higher wound stability because of the intact Descemet membrane. We report a case of a novel management of wound dehiscence following DALK. A 59-year-old patient underwent uncomplicated DALK for advanced keratoconus. Eighteen months later he experienced a traumatic wound dehiscence (globe rupture) after a fall. Visual acuity decreased to light perception on the affected eye, the iris and prolapsed vitreous were incarcerated, and no retinal details were recognizable. The corneal graft was dehiscent over eight clock hours, the Descemet membrane was ruptured, and the stroma dissolved over 30% of its surface in a bell shape. Primary wound closure was performed with nylon 10-0 single interrupted corneal sutures. One day after emergency treatment, a 23-gauge pars-plana-vitrectomy for vitreous hemorrhage was conducted and a retinal tear was treated with laser photocoagulation. The Descemet membrane was repositioned using a 23 g vitrectomy probe under air and the globe was filled with SF gas. Postoperatively, visual acuity increased to 6/15 and the cornea cleared up. Corneal graft and Descemet membrane repositioning after trauma can avoid a further keratoplasty and the risk of immunological rejection of donor endothelial cells. Clin. Anat. 31:56-59, 2018. © 2017 Wiley Periodicals, Inc.

Traumatic globe rupture after deep anterior lamellar keratoplasty-A novel management technique.

To provide insight into the clinical anatomy of Tenon's capsule and to describe a technique to manage sclerocorneal defects using autologous Tenon's tissue. A thin layer of Tenon's capsule harvested from the patient's own eye is used to seal the defect and act as a scaffold. The Tenon's flap is spread over the defect and held in place by Vicryl sutures. A bandage contact lens is then placed on the eye. Tenon's capsule is composed of thick fibrous tissue with smooth muscle fibers and a thin posterior capsule of orbital fat. It is rich in fibroblasts, which can accelerate wound healing and eventually lead to robust scarring without risk of immunogenicity and without cost. Tenonplasty uses easily-available autologous Tenon's tissue in patients with sclerocorneal defects to preserve globe morphology. The technique is a feasible alternative not limited by the availability of graft tissue. Clin. Anat. 31:72-76, 2018. © 2017 Wiley Periodicals, Inc.

Tenonplasty for closing defects during sclerocorneal surgery-A brief review of its anatomy and clinical applications.

Epithelial invasion after open globe injury is a rare complication. Wrong treatment (laser opening of the cyst) or no treatment can lead to painful blindness. Forty percent (25/62) of patients with block excision with epithelial downgrowth had a history of open globe injury. Four of them were female. Their mean age was 45 ±21 years. A tectonic keratoplasty with block excision was performed on 25 patients. Seven of them had simultaneously undergone cataract surgery. The mean extension of epithelial invasion was 3.0 ± 1.3 clock hours. Laser cystotomy was contraindicated. The diameter of the block excision was 8.2 ± 1.5 mm. Histological examination revealed diffuse epithelial invasion in three eyes and cystic epithelial downgrowth in 22 eyes. Mean pre- and post-operative visual acuity (20/60) did not differ significantly. The intraocular pressure was 16 ± 7 mm Hg before and 14 ± 7 mm Hg after the surgery. Only one eye (4%) developed ocular hypotony after block excision. Epithelial invasion can become manifest many years after an open globe injury. En block excision for cystic epithelial downgrowth with an extension less than 150 degrees is the therapy of choice. Opening of the cyst by laser or surgically is not recommended: It can induce transformation of cystic into diffuse epithelial invasion, and the succeeding secondary glaucoma can be refractory to therapy and lead to blindness. Clin. Anat. 31:68-71, 2018. © 2017 Wiley Periodicals, Inc.

Epithelial invasion after open globe injury.

Intraocular pressure lowering surgery in congenital aniridia glaucoma (CAG) can be complicated by dysgenesis of the limbal region, anterior chamber angle, iris, and lens. The anterior segments of 23 eyes (17 patients) with congenital aniridia were investigated under general anesthesia using ultrasound biomicroscopy (UBM). The structures of the anterior segment were examined: distance of ciliary body processes from the anterior chamber angle and positioning of Schlemm's canal. A surgical plan was created on the basis of these data. Schlemm's canal was detected in 21 of the 23 examined eyes. The mean distance from the anterior chamber angle was 1.3 ± 0.4 mm (range: 0.5-to 2.1 mm). The mean distance between the anterior chamber angle and the ciliary body was 561 ± 301 µm (range: 270-1,300 µm). The mean prominence of the ciliary body towards the lens was 799 ± 352 µm (range: 210-1,660 µm). This resulted in a precise UBM-based trabeculotomy. In addition, the ciliary body was detected and coagulated ab externo with a diode laser probe (810 nm) using diaphanoscopy and UBM. An initial UBM examination of the anterior segment is essential in eyes with CAG scheduled for trabeculotomy or cyclophotocoagulation. Clin. Anat. 31:64-67, 2018. © 2017 Wiley Periodicals, Inc.

Clinical anatomy of the anterior chamber angle in congenital aniridia and consequences for trabeculotomy/cyclophotocoagulation.

The aim of this observational study is to evaluate the effectiveness of an adjuvant intracameral corticosteroid injection (ICI) in cases of severe endothelial immune reaction (SEIR) (anterior chamber cells and flare, retrocorneal precipitates, Descemet's folds, and corneal edema) after penetrating keratoplasty and posterior lamellar keratoplasty.

Intracameral Dexamethasone Injection as Adjuvant Therapy in Endothelial Immune Reaction After Penetrating and Posterior Lamellar Keratoplasty: A Retrospective Clinical Observation.

PAX6 is a master gene of ocular development and postnatal ocular equilibrium. Congenital aniridia is the hallmark of PAX6 gene haploinsufficiency (Chr. 11 p. 13), but PAX6-associated aniridia is a profound, progressive pan-ocular developmental disorder often leading to blindness. There is congenital visual impairment with advancing loss of vision mainly due to secondary glaucoma and to corneal blindness caused by limbal stem cell insufficiency (LSCI). LSCI leads to ARK (aniridia-related keratopathy), which typically develops in four stages. Incipient LSCI with vessels starting to grow into the cornea can be imaged by fluorescein anterior segment angiography, which enables fine vessels to be more easily detected than by routine slit lamp examination, especially in patients with nystagmus. Thus, clinical stage 1 ARK is often diagnosed at stage 2 by angiography. Corneal neovascularizations often start at the 12 and 6 positions and subsequently progress circumferentially, not at the 3 and 9 positions as previously believed. Anterior segment angiography can provide an easily standardizable tool for monitoring progress, treatment-induced regress or stabilization of ARK. Especially in children, angiography could be used to monitor new treatment regimens for reducing LSCI. Angiography could enable treatment to begin earlier to preserve corneal hemostasis. In addition, the fact that vascularization often starts at the subpalpebral 6 and 12 positions as opposed to the 3 and 9 positions raises more questions concerning factors that promote LSCI and related corneal injuries. Clin. Anat. 31:392-397, 2018. © 2018 Wiley Periodicals, Inc.

Diagnostic impact of anterior segment angiography of limbal stem cell insufficiency in PAX6-related aniridia.

This study aimed to investigate the influence of three muscle relaxants on intraocular pressure (IOP), ocular pulse amplitude (OPA), and vis-à-tergo (VAT) in patients undergoing penetrating keratoplasty (PKP) under general anesthesia.

Muscle Relaxants as a Risk Factor for Vis-à-tergo During Penetrating Keratoplasty: A Prospective Interventional Study.

To investigate the cytotoxic effect of bleomycin, mitomycin C (MMC) and Fluorouracil (5-FU) in combination with electroporation (EP) on human conjunctival melanoma (CM) and normal conjunctival cell lines using 2D and 3D cell culture systems in vitro.

Conjunctival melanoma and electrochemotherapy: preliminary results using 2D and 3D cell culture models in vitro.

Uveal melanoma (UM) is the most common primary intraocular tumor that arises from neoplastic melanocytes in the choroid, iris, and ciliary body. Electrochemotherapy (ECT) has been successfully established for the treatment of skin and soft tissue metastatic lesions, deep-seated tumors of the liver, bone metastases, and unresectable pancreas lesions. The aim of this study was to evaluate the effect of ECT in vitro in 3D spheroid culture systems in primary and metastatic UM cell lines. We also investigated the chick embryo chorioallantoic membrane (CAM) as an in vivo model system for the growth and treatment of UM tumors using ECT. The cytotoxic effect of ECT in 3D spheroids was analyzed seven days following treatment by assessment of the size and MTT [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium reduction] assay. The cytotoxicity of ECT after intratumoral or intraarterial administration was evaluated histologically. In vitro and in vivo ECT caused a significant reduction in tumor size and viability compared to electroporation or chemotherapy in both sections of our study. The current results underline the effectiveness of ECT in the treatment of UM and prepare the way for further investigation of its potential application in UM.

The Potential Use of Electrochemotherapy in the Treatment of Uveal Melanoma: In Vitro Results in 3D Tumor Cultures and In Vivo Results in a Chick Embryo Model.

A serious problem of the treatment of eye diseases is the very short residence time of the drug. The majority of the drug is cleared within few seconds due to the poor capability of the eye to accommodate additional liquids. We developed a new ocular drug delivery system, which is applied in dry form and forms immediately a gel after administration. The system is based on gellan gum/pullulan electrospun nanofibers. The rheological behavior of the spinning solution was investigated followed by further characterization of the in situ formed gel. Three-dimensional X-ray imaging with nanometric resolution (nano-CT) and electron scanning microscopy were used for a detailed characterization of the diameter and alignment of the fibers. A high porosity (87.5 ± 0.5%) and pore interconnectivity (99%) was found. To ensure a good fit to the eye anatomy, the prepared fibers were shaped into curved geometries. Additionally, a new innovative moistening chamber for the in vitro determination of the ocular residence time in porcine eyes was developed which mimics the tear turnover. A clear prolongation of the fluorescein residence time compared to conventional eye drops was achieved with the application of the curved nanofiber in situ gelling mat. In summary, the developed in situ gelling system with adapted geometry is a promising alternative system for ocular drug delivery.

Article	Year
Methods of fixation of intraocular lenses according to the anatomical structures in trauma eyes. Clinical anatomy (New York, N.Y.)\| PubMed ID: 28509425	2018
Sclerocorneal graft and sequential removal of melted cornea after severe corneal burn with perforation. Clinical anatomy (New York, N.Y.)\| PubMed ID: 28544131	2018
Confocal microscopy as an early relapse marker for acanthamoeba keratitis. Clinical anatomy (New York, N.Y.)\| PubMed ID: 28556202	2018
Traumatic globe rupture after deep anterior lamellar keratoplasty-A novel management technique. Clinical anatomy (New York, N.Y.)\| PubMed ID: 28556252	2018
Tenonplasty for closing defects during sclerocorneal surgery-A brief review of its anatomy and clinical applications. Clinical anatomy (New York, N.Y.)\| PubMed ID: 28612422	2018
Epithelial invasion after open globe injury. Clinical anatomy (New York, N.Y.)\| PubMed ID: 28612462	2018
Clinical anatomy of the anterior chamber angle in congenital aniridia and consequences for trabeculotomy/cyclophotocoagulation. Clinical anatomy (New York, N.Y.)\| PubMed ID: 28613427	2018
Intracameral Dexamethasone Injection as Adjuvant Therapy in Endothelial Immune Reaction After Penetrating and Posterior Lamellar Keratoplasty: A Retrospective Clinical Observation. Advances in therapy\| PubMed ID: 28667581	2017
Diagnostic impact of anterior segment angiography of limbal stem cell insufficiency in PAX6-related aniridia. Clinical anatomy (New York, N.Y.)\| PubMed ID: 28906020	2018
Muscle Relaxants as a Risk Factor for Vis-à-tergo During Penetrating Keratoplasty: A Prospective Interventional Study. Advances in therapy\| PubMed ID: 29101713	2017
Conjunctival melanoma and electrochemotherapy: preliminary results using 2D and 3D cell culture models in vitro. Acta ophthalmologica\| PubMed ID: 30548215	2019
The Potential Use of Electrochemotherapy in the Treatment of Uveal Melanoma: In Vitro Results in 3D Tumor Cultures and In Vivo Results in a Chick Embryo Model. Cancers\| PubMed ID: 31514412	2019
Electrospun nanofibers - A promising solid in-situ gelling alternative for ocular drug delivery. European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V\| PubMed ID: 31816391	2020

Arne Viestenz

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