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Purpose: Bilateral progressive, symmetrical loss of central retinal thickness (CRT) has been described in neuronal ceroid lipofuscinosis type 2 (CLN2) disease. This study details the pattern of morphological changes underlying CRT loss and disease progression in patients receiving intracerebroventricular (ICV) enzyme replacement therapy (ERT) with cerliponase alfa. Methods: Spectral-domain optical coherence tomography macular cube scans were collected from 16 patients with classic CLN2 disease receiving ICV ERT. Detailed retinal structure analyses were performed on manually segmented horizontal B-scans through the fovea to determine the thickness of six retinal parameters and the extent of ellipsoid zone (EZ) loss. Results: Anatomical changes primarily occurred in photoreceptor (PR)-related retinal parameters and correlated with ocular disease severity. Retinal degeneration began with initial focal parafoveal EZ discontinuities signaling the onset of rapid PR degeneration in a predictable pattern: parafoveal PR involvement with foveal sparing followed by profound parafoveal and foveal PR loss with additional thinning beyond the central retina. PR degeneration began with outer segment loss and progressed to outer nuclear layer (ONL) involvement. Longitudinal analyses confirmed these observations. The rate of PR loss was fastest at the fovea at â¼58 mm per year and became slower at locations farther away from the fovea. Conclusions: Retinal degeneration in CLN2 disease is primarily associated with PR loss in a predictable pattern, with EZ disruption signaling early PR stress. CRT, ONL thickness, and PR layer thickness are useful anatomical biomarkers for understanding disease progression and treatment efficacy in CLN2. Studies using en face images will further clarify CLN2-related retinal degeneration.
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Biomarcadores , Terapia de Reemplazo Enzimático , Lipofuscinosis Ceroideas Neuronales , Tomografía de Coherencia Óptica , Humanos , Tomografía de Coherencia Óptica/métodos , Terapia de Reemplazo Enzimático/métodos , Lipofuscinosis Ceroideas Neuronales/tratamiento farmacológico , Masculino , Femenino , Niño , Adolescente , Biomarcadores/metabolismo , Adulto , Adulto Joven , Retina/diagnóstico por imagen , Retina/patología , Agudeza Visual/fisiología , Progresión de la Enfermedad , Preescolar , Dipeptidil-Peptidasas y Tripeptidil-Peptidasas , Proteínas RecombinantesRESUMEN
PURPOSE: Traction exerted on the vitreous base during vitrectomy poses a risk for retinal tears. We aimed to quantify core vitreous traction during vitrectomy using spring return and pneumatic cutters. METHODS: Juvenile porcine vitreous was vacuum held in a vitreous bath while traction was measured using precision force gauge during vitrectomy. The parameters included were aspiration rate, cut-rate, cutter size, and machine types. RESULTS: An empirical probabilistic model was developed. The traction was proportional to the aspiration rate but insignificantly dependent on the cut-rate. The traction probability was inversely proportional to the exponential function of the traction (p < 0.05). The traction was < 0.003 N for 99% of the time using either 23- or 25-gauge cutters. CONCLUSION: The tractions measured were considered similar to the causative forces of an iatrogenic retinal tear during a pars plana vitrectomy. The results provide a safety reference matrix of instrumental parameters during vitrectomy.
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Vitrectomía , Cuerpo Vítreo , Animales , Humanos , Microcirugia , Modelos Estadísticos , Porcinos , Tracción , Cuerpo Vítreo/cirugíaRESUMEN
PURPOSE: To characterize histologic changes in the optic nerve and the retina of an end-stage retinitis pigmentosa (RP) patient after long-term implantation with the Argus II retinal prosthesis system. METHODS: Serial cross sections from the patient's both eyes were collected postmortem 6 years after implantation. Optic nerve from both eyes were morphometrically analyzed and compared. Retina underneath and outside the array was analyzed and compared with corresponding regions in the fellow eye. RESULTS: Although the optic nerve of the implant eye demonstrated significantly more overall atrophy than the fellow eye (P < 0.01), the temporal quadrant that retinotopically corresponded to the location of the array did not show additional damage. The total neuron count of the macular area was not significantly different between the two eyes, but the tack locations and their adjacent areas showed significantly fewer neurons than other perimacular areas. There was an increased expression of glial fibrillary acidic protein (GFAP) throughout the retina in the implant eye versus the fellow eye, but there was no significant difference in the cellular retinaldehyde-binding protein (CRALBP) expression. Except for the revision tack site, no significant increase of inflammatory reaction was detected in the implant eye. CONCLUSION: Long-term implantation and electrical stimulation with an Argus II retinal prosthesis system did not result in significant tissue damage that could be detected by a morphometric analysis. TRANSLATIONAL RELEVANCE: This study supports the long-term safety of the Argus II device and encourages further development of bioelectronics devices at the retina-machine interface.
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Open globe injuries are full-thickness injuries sustained to the eye wall (cornea or sclera), which cause immediate drops in intraocular pressure that may lead to retinal detachment and permanent vision loss if not treated rapidly after injury. The current standard of care for open globe injuries consists of suturing the margins closed, but the technique can be time-consuming, requires specialized training and equipment, and can lead to patient discomfort, abrasion, and infection from eye rubbing. We engineered an injectable, thermoresponsive sealant (TRS) and a custom tool to occlude open globe injuries. The smart hydrogel sealant consists of physically cross-linked N-isopropylacrylamide copolymerized with butylacrylate. At low temperatures, it can be injected as a liquid, and when raised to body temperature, a heat-induced gelation converts the hydrogel into a solidified occlusion. The sealant can be repositioned or removed without causing additional trauma via exposure to cold water. In vitro and ex vivo assessments of mechanical adhesion to eye tissue revealed maintenance of intraocular pressure that is five times greater than the physiological range with reversible seal strength comparable to cyanoacrylate (super glue). In vivo assessment in a rabbit model of ocular trauma demonstrated ease of use for TRS deployment, statistically significant improvement in wound sealing, and no evidence of neurotoxicity, retinal tissue degradation, or significant chronic inflammatory response after 30 days of exposure. Given the advantages of body heat-induced gelation, rapid reversible occlusion, and in vivo safety and efficacy, shape-adaptable TRSs have translational potential as smart wound sealants for temporary occlusion of surgical incisions or traumatic injuries.
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Inflamación/cirugía , Retina/patología , Animales , Córnea/inmunología , Córnea/patología , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Conejos , Retina/inmunología , Agudeza Visual/fisiologíaRESUMEN
BACKGROUND: Subretinal cell transplantation is a challenging surgical maneuver. This paper describes the preliminary findings of a new tissue injector for subretinal implantation of an ultrathin non-absorbable substrate seeded with human embryonic stem cell-derived retinal pigment epithelium (hESC-RPE). METHODS: Ultrathin Parylene-C substrates measuring 3.5 mm × 6.0 mm seeded with hESC-RPE (implant referred to as CPCB-RPE1) were implanted into the subretinal space of 12 Yucatan minipigs. Animals were euthanized immediately after the procedure and underwent spectral domain optical coherence tomography (SD-OCT) and histological analysis to assess the subretinal placement of the implant. Evaluation of the hESC-RPE cells seeded on the substrate was carried out before and after implantation using standard cell counting techniques. RESULTS: The tissue injector delivered the CPCB-RPE1 implant through a 1.5 mm sclerotomy and a 1.0-1.5 mm retinectomy. SD-OCT scans and histological examination revealed that substrates were precisely placed in the subretinal space, and that the hESC-RPE cell monolayer continued to cover the surface of the substrate after the surgical procedure. CONCLUSION: This innovative tissue injector was able to efficiently deliver the implant in the subretinal space of Yucatan minipigs, preventing significant hESC-RPE cell loss, minimizing tissue trauma, surgical complications and postoperative inflammation.
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Dysfunction and death of retinal pigment epithelium (RPE) and or photoreceptors can lead to irreversible vision loss. The eye represents an ideal microenvironment for stem cell-based therapy. It is considered an "immune privileged" site, and the number of cells needed for therapy is relatively low for the area of focused vision (macula). Further, surgical placement of stem cell-derived grafts (RPE, retinal progenitors, and photoreceptor precursors) into the vitreous cavity or subretinal space has been well established. For preclinical tests, assessments of stem cell-derived graft survival and functionality are conducted in animal models by various noninvasive approaches and imaging modalities. In vivo experiments conducted in animal models based on replacing photoreceptors and/or RPE cells have shown survival and functionality of the transplanted cells, rescue of the host retina, and improvement of visual function. Based on the positive results obtained from these animal experiments, human clinical trials are being initiated. Despite such progress in stem cell research, ethical, regulatory, safety, and technical difficulties still remain a challenge for the transformation of this technique into a standard clinical approach. In this review, the current status of preclinical safety and efficacy studies for retinal cell replacement therapies conducted in animal models will be discussed.
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PURPOSE: A subretinal implant termed CPCB-RPE1 is currently being developed to surgically replace dystrophic RPE in patients with dry age-related macular degeneration (AMD) and severe vision loss. CPCB-RPE1 is composed of a terminally differentiated, polarized human embryonic stem cell-derived RPE (hESC-RPE) monolayer pre-grown on a biocompatible, mesh-supported submicron parylene C membrane. The objective of the present delivery study was to assess the feasibility and 1-month safety of CPCB-RPE1 implantation in Yucatán minipigs, whose eyes are similar to human eyes in size and gross retinal anatomy. METHODS: This was a prospective, partially blinded, randomized study in 14 normal-sighted female Yucatán minipigs (aged 2 months, weighing 24-35 kg). Surgeons were blinded to the randomization codes and postoperative and post-mortem assessments were performed in a blinded manner. Eleven minipigs received CPCB-RPE1 while three control minipigs underwent sham surgery that generated subretinal blebs. All animals except two sham controls received combined local (Ozurdex™ dexamethasone intravitreal implant) and systemic (tacrolimus) immunosuppression or local immunosuppression alone. Correct placement of the CPCB-RPE1 implant was assessed by in vivo optical coherence tomography and post-mortem histology. hESC-RPE cells were identified using immunohistochemistry staining for TRA-1-85 (a human marker) and RPE65 (an RPE marker). As the study results of primary interest were nonnumerical no statistical analysis or tests were conducted. RESULTS: CPCB-RPE1 implants were reliably placed, without implant breakage, in the subretinal space of the minipig eye using surgical techniques similar to those that would be used in humans. Histologically, hESC-RPE cells were found to survive as an intact monolayer for 1 month based on immunohistochemistry staining for TRA-1-85 and RPE65. CONCLUSIONS: Although inconclusive regarding the necessity or benefit of systemic or local immunosuppression, our study demonstrates the feasibility and safety of CPCB-RPE1 subretinal implantation in a comparable animal model and provides an encouraging starting point for human studies.
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Células Madre Embrionarias Humanas/trasplante , Degeneración Macular/cirugía , Epitelio Pigmentado de la Retina/trasplante , Trasplante de Células Madre/métodos , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Estudios de Factibilidad , Femenino , Humanos , Degeneración Macular/diagnóstico , Estudios Prospectivos , Epitelio Pigmentado de la Retina/citología , Porcinos , Porcinos Enanos , Tomografía de Coherencia Óptica , Resultado del TratamientoRESUMEN
PURPOSE: To determine the safety, survival, and functionality of human embryonic stem cell-derived RPE (hESC-RPE) cells seeded on a polymeric substrate (rCPCB-RPE1 implant) and implanted into the subretinal (SR) space of Royal College of Surgeons (RCS) rats. METHODS: Monolayers of hESC-RPE cells cultured on parylene membrane were transplanted into the SR space of 4-week-old RCS rats. Group 1 (n = 46) received vitronectin-coated parylene membrane without cells (rMSPM+VN), group 2 (n = 59) received rCPCB-RPE1 implants, and group 3 (n = 13) served as the control group. Animals that are selected based on optical coherence tomography screening were subjected to visual function assays using optokinetic (OKN) testing and superior colliculus (SC) electrophysiology. At approximately 25 weeks of age (21 weeks after surgery), the eyes were examined histologically for cell survival, phagocytosis, and local toxicity. RESULTS: Eighty-seven percent of the rCPCB-RPE1-implanted animals showed hESC-RPE survivability. Significant numbers of outer nuclear layer cells were rescued in both group 1 (rMSPM+VN) and group 2 (rCPCB-RPE1) animals. A significantly higher ratio of rod photoreceptor cells to cone photoreceptor cells was found in the rCPCB-RPE1-implanted group. Animals with rCPCB-RPE1 implant showed hESC-RPE cells containing rhodopsin-positive particles in immunohistochemistry, suggesting phagocytic function. Superior colliculus mapping data demonstrated that a significantly higher number of SC sites responded to light stimulus at a lower luminance threshold level in the rCPCB-RPE1-implanted group. Optokinetic data suggested both implantation groups showed improved visual acuity. CONCLUSIONS: These results demonstrate the safety, survival, and functionality of the hESC-RPE monolayer transplantation in an RPE dysfunction rat model.
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Células Madre Embrionarias/citología , Polímeros , Degeneración Retiniana/patología , Epitelio Pigmentado de la Retina/patología , Trasplante de Células Madre , Animales , Recuento de Células , Supervivencia Celular , Células Cultivadas , Modelos Animales de Enfermedad , Humanos , Ratas , Ratas Mutantes , Degeneración Retiniana/cirugía , Epitelio Pigmentado de la Retina/fisiopatología , Tomografía de Coherencia ÓpticaRESUMEN
BACKGROUND AND OBJECTIVE: To develop a safe and efficient surgical procedure for subretinal implantation into porcine eyes of a human embryonic stem cell-derived retinal pigmented epithelium (hESC-RPE) monolayer seeded onto a Parylene-C scaffold. This implant is referred to as CPCB-RPE1. MATERIALS AND METHODS: Ultrathin Parylene-C scaffolds were seeded with hESC-RPE and surgically implanted into the subretinal space of Yucatan mini pigs (n = 8). The surgery consisted of pars plana vitrectomy, induction of a limited retinal detachment, and peripheral retinotomy for insertion of the monolayer using a novel tissue injector, followed by silicone oil tamponade injection, laser photocoagulation around the retinotomy site, and inferior iridectomy. Oral cyclosporine was administered from day 1 and during the entire follow-up period. Three months later, the animals were euthanized and the eyes and major organs were submitted for histological analysis. Adjacent sections underwent immunohistochemical analysis to detect human cells using anti-TRA-1-85 (human blood group antigen) antibody and DAPI antibodies. RESULTS: The cell monolayer was immunopositive for TRA-1-85 3 months after implantation and migration from the Parylene-C scaffold was not detected. One eye had a mild inflammatory reaction around the implant that was negative for human biomarkers. No intraocular or systemic tumors were detected. CONCLUSION: The hESC-RPE cells survived for 3 months in this animal model. The surgical procedure for subretinal implantation of CPCB-RPE1 is feasible and safe, without cell migration off the scaffold or development of ocular or systemic tumors.
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Células Madre Embrionarias Humanas/trasplante , Procedimientos Quirúrgicos Oftalmológicos , Retina/cirugía , Epitelio Pigmentado de la Retina/citología , Trasplante de Células Madre , Animales , Células Cultivadas , Angiografía con Fluoresceína , Humanos , Polímeros , Retina/diagnóstico por imagen , Porcinos , Porcinos Enanos , Andamios del Tejido , Tomografía de Coherencia Óptica , Trasplante Heterólogo , XilenosRESUMEN
PURPOSE: To evaluate intraocular pressure (IOP) changes during experimental vitrectomy and the efficacy of Constellation Vision System's IOP control (IOPc) feature in reestablishing baseline pressure. METHODS: Using a pressure transducer in freshly enucleated porcine eyes, a broad range of parameters (baseline pressures, aspiration levels, and cut rates) were tested with 23- and 25-gauge probes and IOPc turned ON versus OFF. RESULTS: IOPc turned ON was significantly more effective than IOPc turned OFF in controlling IOP drop and stabilizing pressure during vitrectomy using a wide range of baseline pressures (20-70 mmHg). The 23-gauge system consistently presented a reduced drop from baseline compared with the 25-gauge system. The overall average drop for the 23- and 25-gauge systems was 12.79 mmHg and 21.17 mmHg, respectively. Both gauge sizes reestablished baseline pressure approximately 1.6 seconds after the initial pressure drop generated at the beginning of aspiration. A peak of IOP (overshooting) was observed when the pressure was returning to baseline using both 23- and 25-gauge systems. CONCLUSION: Using IOPc feature turned ON, 23- and 25-gauge probes were effective in reestablishing and sustaining baseline infusion pressures, although 23-gauge probes showed less IOP fluctuation than did 25-gauge probes.
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Presión Intraocular/fisiología , Vitrectomía , Animales , Esclerostomía , Porcinos , Tonometría Ocular , Transductores de PresiónRESUMEN
PURPOSE: Magnetic resonance imaging (MRI) can measure the effects of vision loss and recovery on brain function and structure. In this case study, we sought to determine the feasibility of acquiring anatomical and functional MRI data in recipients of the Argus II epiretinal prosthesis system. METHODS: Following successful implantation with the Argus II device, two retinitis pigmentosa (RP) patients completed MRI scans with their implant unpowered to measure primary visual cortex (V1) functional responses to a tactile task, whole-brain morphometry, V1 cortical thickness, and diffusion properties of the optic tract and optic radiation. Measurements in the subjects with the Argus II implant were compared to measurements obtained previously from RP patients and sighted individuals. RESULTS: The presence of the Argus II implant resulted in artifacts that were localized around the patient's implanted eye and did not extend into cortical regions or white matter tracts associated with the visual system. Structural data on V1 cortical thickness and the retinofugal tract obtained from the two Argus II subjects fell within the ranges of sighted and RP groups. When compared to the RP and sighted subjects, Argus II patients' tactile-evoked cross-modal functional MRI (fMRI) blood oxygen level-dependent (BOLD) responses in V1 also fell within the range of either sighted or RP groups, apparently depending on time since implantation. CONCLUSIONS: This study demonstrates that successful acquisition and quantification of structural and functional MR images are feasible in the presence of the inactive implant and provides preliminary information on functional changes in the brain that may follow sight restoration treatments. TRANSITIONAL RELEVANCE: Successful MRI and fMRI acquisition in Argus II recipients demonstrates feasibility of using MRI to study the effect of retinal prosthesis use on brain structure and function.
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PURPOSE: The Argus I implant is the first-generation epiretinal prosthesis approved for an investigational clinical trial by the United States Food and Drug Administration. Herein we report testing results obtained from a 10-year follow-up to study the physiologic effects of the bioelectronic visual implant after prolonged chronic electrical stimulation. DESIGN: Case report. PARTICIPANT: One man, 55 years of age when enrolled in the study, underwent surgical implantation of the Argus I in June 2004, followed by periodic tests from July 2004 through June 2014, spanning a total of 10 years. METHODS: The decade-long follow-up consisted of implant system performance tests, subject visual function evaluation, and implant-retina interface analysis. MAIN OUTCOME MEASURES: Changes in electrode impedance and perceptual threshold over the time course; subject's performance on visual function task, orientation, and mobility tests; and optical coherence tomography data, fundus imaging, and fluorescein angiography results for the assessment of subject's implant-retina physical interface. RESULTS: Electrically elicited phosphenes were present 10 years after implantation of an epiretinal stimulator. The test subject not only was able to perceive phosphenes, but also could perform visual tasks at rates well above chance. CONCLUSIONS: This decade-long follow-up report provides further support for the use of retinal prostheses as a long-lasting treatment for some types of blindness.
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Ceguera/rehabilitación , Fosfenos/fisiología , Retina/fisiopatología , Percepción Visual/fisiología , Prótesis Visuales , Ceguera/fisiopatología , Impedancia Eléctrica , Electrodos Implantados , Angiografía con Fluoresceína , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Implantación de Prótesis , Umbral Sensorial , Terapias en Investigación , Tomografía de Coherencia ÓpticaRESUMEN
Descrevemos um caso de perda visual irreversível bilateral em uma paciente de 64 anos após uso prolongado de paclitaxel. Ao exame oftalmológico paciente apresentou acuidade visual (AV) de 20/400 em ambos os olhos (AO) na primeira consulta. À tomografia de coerência óptica (TCO) evidenciou espessamento macular AO. Após seis meses da suspensão do paclitaxel, a paciente apresentava melhora discreta da AV atingindo 20/200 com correção em AO, além da TCO demonstrando resolução do espessamento retiniano.
We describe a case of bilateral irreversible visual loss of a 64 year-old patient after prolonged use of paclitaxel. Patient presented best corrected visual acuity of 20/400 in both eyes at first visit and optical coherence tomography showed increased macular in both eyes.After six months of the interruption of -paclitaxel therapy, the patient showed slight improvement of visual acuity reaching 20/200 in both eyes, while OCT demonstrated resolution of macular edema.
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Humanos , Femenino , Persona de Mediana Edad , Agudeza Visual , Antineoplásicos Fitogénicos/efectos adversos , Antineoplásicos Fitogénicos/toxicidad , Edema Macular/inducido químicamente , Paclitaxel/efectos adversos , Paclitaxel/toxicidadRESUMEN
Age-related macular degeneration (AMD) is the leading cause of blindness among the elderly in developed countries. AMD is classified as either neovascular (NV-AMD) or non-neovascular (NNV-AMD). Cumulative damage to the retinal pigment epithelium, Bruch's membrane, and choriocapillaris leads to dysfunction and loss of RPE cells. This causes degeneration of the overlying photoreceptors and consequential vision loss in advanced NNV-AMD (Geographic Atrophy). In NV-AMD, abnormal growth of capillaries under the retina and RPE, which leads to hemorrhage and fluid leakage, is the main cause of photoreceptor damage. Although a number of drugs (e.g., anti-VEGF) are in use for NV-AMD, there is currently no treatment for advanced NNV-AMD. However, replacing dead or dysfunctional RPE with healthy RPE has been shown to rescue dying photoreceptors and improve vision in animal models of retinal degeneration and possibly in AMD patients. Differentiation of RPE from human embryonic stem cells (hESC-RPE) and from induced pluripotent stem cells (iPSC-RPE) has created a potentially unlimited source for replacing dead or dying RPE. Such cells have been shown to incorporate into the degenerating retina and result in anatomic and functional improvement. However, major ethical, regulatory, safety, and technical challenges have yet to be overcome before stem cell-based therapies can be used in standard treatments. This review outlines the current knowledge surrounding the application of hESC-RPE and iPSC-RPE in AMD. Following an introduction on the pathogenesis and available treatments of AMD, methods to generate stem cell-derived RPE, immune reaction against such cells, and approaches to deliver desired cells into the eye will be explored along with broader issues of efficacy and safety. Lastly, strategies to improve these stem cell-based treatments will be discussed.
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Células Madre Embrionarias/citología , Degeneración Macular/terapia , Epitelio Pigmentado de la Retina , Trasplante de Células Madre/métodos , Técnicas de Cultivo de Célula , Humanos , Células Madre Pluripotentes/citología , Neovascularización Retiniana/terapia , Epitelio Pigmentado de la Retina/citología , Epitelio Pigmentado de la Retina/trasplanteRESUMEN
BACKGROUND AND OBJECTIVE: To compare the water and vitreous flow rates and duty cycle (DC) between two ultrahigh-speed vitrectomy systems: pneumatic with spring return (SR) and dual pneumatic (DP) probes. MATERIALS AND METHODS: The flow rate was calculated using a high-sampling precision balance that measured the mass of water and vitreous removed from a vial by a vitreous cutter. Frame-by-frame analysis of a high-speed video of the cutter was used to determine the DC. Three cutters of each gauge (20, 23, and 25 G) were tested with an SR and a DP system using the standard DC setting (biased open) at 0 (water only), 1,000, 2,000, 3,000, 4,000, and 5,000 cuts per minute (CPM) with aspiration levels of 100, 200, 300, 400, 500, and 600 mm Hg. RESULTS: The DC was slightly higher with the SR system using most parameters and gauges although without statistical significance. The water flow rate was somewhat higher with the SR system, except for 25 G with 4,000 and 5,000 CPM. The vitreous flow rate was similar using most parameters, with the SR system showing higher flows at lower cut rates (1,000-3,000 CPM). CONCLUSIONS: SR and DP systems produced similar water and vitreous flow rates. Additional studies in human eyes are necessary to confirm these findings.
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Hidrodinámica , Microcirugia/instrumentación , Vitrectomía/instrumentación , Cuerpo Vítreo/cirugía , Animales , Succión , Porcinos , Grabación en Video , Agua/fisiologíaRESUMEN
PURPOSE: We hypothesized that reaction times (RTs) for a switch release are faster for hand-controlled than for foot-controlled switches for physiological and anatomical reasons (e.g., nerve conduction speed). The risk of accidental trauma could be reduced if the surgeon reacted quicker and therefore improve the surgical outcome. METHOD: We included 47 medical professionals at USC. Demographics and handedness were recorded. Under a microscope, a simple reaction time test was performed, testing all extremities multiple times in a random order. Additionally, a subjective questionnaire was administered. RESULTS: The mean RTs for hands are 318.24 ms ± 51.13 and feet 328.69 ± 48.70. The comparison of hand versus foot showed significant shorter RTs for the hand (P = 0.025). Partially significant differences between and within the experience level groups could be demonstrated by level of education (LE) and microscopic surgeries/week (MSW) (P = 0.57-0.02). In the subjective questionnaire, 91.5% (n = 43/47) of test subjects prefer to use hand controls. CONCLUSION: Our data show that the RT for hands is faster than feet. Similarly the subjective questionnaire showed a greater preference for hand actuation. This data suggest a hand-controlled ophthalmic instrument might have distinct advantages; however, clinical correlation is required.
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Procedimientos Quirúrgicos Oftalmológicos/normas , Tiempo de Reacción/fisiología , Estudiantes de Medicina , Cirujanos , Adulto , Femenino , Pie/fisiología , Mano/fisiología , Humanos , Masculino , Encuestas y CuestionariosRESUMEN
The recent approval by the US Food and Drug Administration of ocriplasmin for the treatment of symptomatic vitreomacular adhesion (VMA), often associated with vitreomacular traction (VMT) and macular hole (MH), has brought new attention to the field of pharmacologic vitreolysis. The need for an enzyme to split the vitreomacular interface, which is formed by a strong adhesive interaction between the posterior vitreous cortex and the internal limiting membrane, historically stems from pediatric eye surgery. This review summarizes the different anatomic classifications of posterior vitreous detachment or anomalous posterior vitreous detachment and puts these in the context of clinical pathologies commonly observed in clinical practice of the vitreoretinal specialist, such as MH, VMT, age-related macular degeneration, and diabetic macular edema. We revisit the outcome of the Phase II studies that indicated ocriplasmin was a safe and effective treatment for selected cases of symptomatic VMA and MH. Release of VMA at day 28 was achieved by 26.5% of patients in the ocriplasmin group versus 10.1% in the placebo group (P<0.001). Interestingly, for MHs, the numbers were more remarkable. Predictive factors for successful ocriplasmin treatment were identified for VMT (VMA diameter smaller than 1,500 µm) and MH (smaller than 250 µm). In comparison with the highly predictable outcome after vitrectomy, the general success rate of ocriplasmin not under clinical trial conditions has not fully met expectations and needs to be proven in real-world clinical settings. The ocriplasmin data will be compared in the future with observational data on spontaneous VMA release, will help retina specialists make more accurate predictions, and will improve outcome rates.
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Diabetic retinopathy (DR) is an important cause of vision loss around the world, being the leading cause in the population between 20 and 60 years old. Among patients with DR, diabetic macular edema (DME) is the most frequent cause of vision impairment and represents a significant public health issue. Macular photocoagulation has been the standard treatment for this condition reducing the risk of moderate visual loss by approximately 50%. The role of vascular endothelial growth factor (VEGF) in DR and DME pathogenesis has been demonstrated in recent studies. This review addresses and summarizes data from the clinical trials that investigated anti-VEGF for the management of DME and evaluates their impact on clinical practice. The literature searches were conducted between August and October 2013 in PubMed and Cochrane Library with no date restrictions and went through the most relevant studies on pegaptanib, ranibizumab, bevacizumab, and aflibercept for the management of DME. The efficacy and safety of intravitreal anti-VEGF as therapy for DME have recently been proved by various clinical trials providing significantly positive visual and anatomical results. Regarding clinical practice, those outcomes have placed intravitreal injection of anti-VEGF as an option that must be considered for the treatment of DME.
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Anticuerpos Monoclonales Humanizados/uso terapéutico , Aptámeros de Nucleótidos/uso terapéutico , Retinopatía Diabética/terapia , Edema Macular/terapia , Receptores de Factores de Crecimiento Endotelial Vascular/uso terapéutico , Proteínas Recombinantes de Fusión/uso terapéutico , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Bevacizumab , Ensayos Clínicos como Asunto , Retinopatía Diabética/complicaciones , Retinopatía Diabética/inmunología , Retinopatía Diabética/patología , Expresión Génica , Humanos , Inyecciones Intravítreas , Fotocoagulación , Edema Macular/complicaciones , Edema Macular/inmunología , Edema Macular/patología , Ranibizumab , Factor A de Crecimiento Endotelial Vascular/genéticaRESUMEN
O objetivo deste relato de caso é descrever uma nova técnica de refixação escleral, unilateral, de uma háptica cuja sutura escleral prévia rompeu-se, levando ao deslocamento da lente intraocular para o vítreo. Trata-se de um olho submetido anteriormente a dois transplantes de córnea, em que se buscou minimizar a manipulação intraocular e o trauma cirúrgico. Esta técnica consiste em realizar o procedimento em olho fechado, utilizando a mesma lente de fixação, sem a necessidade de externalizar as hápticas ou do uso de instrumentos cirúrgicos especiais. A perda de células endoteliais após o procedimento foi similar à observada após a facoemulsificação em pacientes com ceratoplastia penetrante. A técnica mostrou-se simples, segura, e, portanto, reprodutível, além de ser menos invasiva do que os métodos já descritos, permitindo a reabilitação visual precoce do paciente.
The purpose of this case report is to describe a new technique to re-establish a scleral fixation of one luxated haptic, which previous suture ruptured, causing the fall of the intraocular lens into the vitreous cavity. Considering that the patient underwent two penetrant keratoplasty surgeries, there was a major concern to cause minimal intraocular manipulation and less surgical trauma. This technique consists in a closed eye procedure using the fixation lens, without exposing the haptics or using special surgical instruments. The endothelial cell loss after the surgery was similar to that observed after phacoemulsification in eyes with penetrating keratoplasty. The technique proved to be simple, safe, and therefore reproducible, less invasive than the previously published methods and promoted the patient's early visual rehabilitation.