Research In Ophthalmology Research Articles

Protective Effects of Trimetazidine in Retarding Selenite-Induced Lens Opacification

ABSTRACTPurpose: Cataracts are the leading cause of vision loss worldwide, and the over-production of reactive oxygen species (ROS) is the foremost underlying cause of cataracts. Reducing ROS levels can efficiently prevent lens opacification, as evidenced by many studies. Here, we inhibited ROS overproduction with trimetazidine (TMZ), which is an antioxidant, to explore the therapeutic effects of TMZ and the mechanism of lens opacification.Materials and methods: Sodium selenite-induced cataract formation resulted in a significant loss of lens transparency. This effect could be efficiently rescued by TMZ, which was further found to be an inhibitor of ROS production, as determined by assaying oxidative stress-related parameters (SOD activity, MDA, ·OH and H2O2 levels) during cataract formation. The experimental protocols involving animal research were approved by the Animal Care and Ethics Committee of Wenzhou Medical University and conducted according to the Association for Research in Vision and Ophthalmology under the guidelines of the Animal Welfare Act (SYXK 2015–0009).Results: Our study found that TMZ can retard the onset and progression of lens opacification in vivo in experiments using Sprague-Dawley (SD) suckling rats and can rescue the morphology of HLEB3 cells in vitro. The flow cytometry and DNA fragmentation assays showed that TMZ could prevent sodium selenite-induced apoptosis. The western blot analysing showed that the levels of apoptosis-associated Bcl-2 and Nrf2 were dramatically decreased following the sodium selenite treatment. In addition, the bisulfate DNA sequencing revealed that the demethylation of CpGs in the promoter region of Keap1 was stimulated, and that this demethylation could be inhibited by TMZ by rescuing the Nrf2 expression level.Conclusions: Our findings indicate that the antioxidant TMZ strongly reduces ROS production, which ultimately delays the progression of cataract formation, suggesting that treatment with TMZ represents a novel, promising antioxidant protection to retard cataract formation.

Artificial intelligence, robotics and cyborgs: The future of research and technological development in ophthalmology

Artificial intelligence, robotics and cyborgs: The future of research and technological development in ophthalmology

Blind Source Separation of Different Retinal Pulsatile Patterns from Simultaneous Long-term Binocular Ophthalmoscopic Video-records.

Optical imaging of retinal hemodynamic function is an important part of ophthalmologic research. Development and inventing of imaging devices and data analysis methods are both just in progress. The current study innovatively implements two blind source separation (BSS) techniques (i.e. spatial Principal Component Analysis - sPCA; and spatial Independent Component Analysis - sICA) in application of an automatic detection and segmentation of a distinct Optic Disc (OD) areas with different hemodynamic properties from a simultaneous binocular video-ophthalmoscopic records. Both methods detected 3 different spatial patterns mostly symmetric over both eyes stable and reproducible over investigated participants, i.e. central Spontaneous Vessel Pulsations (SVPs), inner OD intensity pulsations and other OD pulsations. Dynamics of all mentioned patterns has a periodic character with similar main frequency (possibly corresponding to subject-specific heart rate) but shifted phase decreasing patterns' mutual high cross-correlations. The sICA estimates a higher rate of phase shifts than sPCA.

Cell-Based Gene Therapy Using the Sleeping Beauty Transposon System Reduces Neovascularisation in Rats

Background: Age-related macular degeneration (AMD) is a progressive retinal disorder, characterised by imbalanced pro- and anti-angiogenic signals, leading vision loss. The aim of this study was to evaluate the effect of ex vivo cell-based gene therapy on primary cells with stable expression of human pigment epithelium derived factor (PEDF) release using the non-viral Sleeping Beauty (SB100X) transposon system delivered by miniplasmids free of antibiotic resistance markers (pFAR4). Methods: Rat retinal pigment epithelial cells (RPEs) and iris pigment epithelial cells (IPEs) were co-transfected with pFAR4-ITRs CMV PEDF BGH and pFAR4-CMV-SB100X-SV40 plasmids. Laser-induced choroidal neovascularization (CNV) was performed in rats and transfected primary cells (tRPE and tIPE) were injected into the subretinal space. The leakage and CNV areas, vascular endothelial growth factor (VEGF), PEDF protein expression, metalloproteinase 2 and 9 (MMP-2/9) and microglial/macrophage markers were measured and evaluated. Findings: The animals injected with tRPE/IPE cells significantly showed a reduction in the leakage area at 14 days while at 7 days only tIPE cells showed a significant reduction. The CNV area at 7 days was reduced with tRPE/IPE cells. There was a significant increase in PEDF and PEDF/VEGF ratio with tRPE cells along with a reduction in the MMP-2 activity. Activated microglial fluorescence intensity increased in all groups analyzed. Interpretation: Our data demonstrate that a single administration of SB100X-engineered RPE/IPE cells release enough hPEDF to favour an anti-angiogenic environment that ultimately reduces CNV suggest that ex vivo non-viral gene therapy could be an effective and safe therapeutic option for angiogenic retinal diseases. Funding: This work was supported by the European Union’s Seventh Framework Programme for research, technological development and demonstration, grant agreement no. 305134 and Fundacion Jesus Gangoiti Barrera. LGG received a predoctoral grant from the Asociacion de Amigos de la Universidad de Navarra. Declaration of Interest: A. Garcia-Layana is consultant in Thea, Allergan, Bayer, Novartis and Roche Laboratories. Z. Izsvak and Z. Ivics are co-inventors on several patents on Sleeping Beauty transposon technology. Ethical Approval: The study was performed according to the Association for Research in Vision and Ophthalmology (ARVO) Resolution on the Use of Animals in Ophthalmic and Vision Research and approved by the Ethics Committee for Animal Research of the University of Navarra (protocol approval number 023-13).

The progress and prospect of ophthalmological research on cerebral visual impairment in children

With the rapid development of global perinatal medicine and neonatal medicine, the survival rate of high-risk neonates (premature, and those who suffer neurologic lesion during or shortly after birth, et al.) improved significantly, however the incidence of cerebral visual impairment (CVI) also rose, which has become the most common cause of visual impairment in children in developed countries. Studies found that visual abnormalities of patients with CVI can be various. Since children's cognition and motor development are inseparable from visual functions, children with CVI are usually characterized by abnormalities in sensory perception, cognition and even movement, other than visual impairment itself. Due to the characteristics of CVI, such as early onset, complex etiology, difficulty in diagnosis and treatment, and involvement with ophthalmology, pediatrics, rehabilitation medicine, genetic epidemiology and other multi-disciplinary content, current domestic research on CVI is limited. From the perspective of ophthalmologist, this paper reviews the progress of ophthalmology diagnosis and treatment in children with CVI in recent years, aiming to have better early recognition and individualized intervention, so as to help pediatrician and rehabilitation physicians to improve survival skills for CVI children and their quality of life. (Chin J Ophthalmol, 2019, 55:469-474).

Dietary Supplement Crocetin Has a Suppressive Effect Against Myopia Progression: A Randomized Clinical Trial

Background: The natural carotenoid crocetin has been reported to suppress experimental myopia in mice. The purpose of this study is to investigate the minimum effective dosage and the preventive efficacy of crocetin with a murine model and human subjects, respectively. Methods: Three-week-old male mice (C57B6/J) were equipped with a -30 diopter (D) lens. Changes of refractive errors and axial lengths (AL) were evaluated to determine the minimum effective dosage. A multicenter randomized double-blind placebo-controlled clinical trial was performed with 69 participants aged 6 to 12 years, whose cycloplegic spherical equivalent refractions (SER) were between -1.5 and -4.5 D. We evaluated AL elongation and change of SER for 24 weeks. A mixed effect model was used for analysis using both eyes. Findings: As the minimum dose, 0.001% of crocetin containing extract chow showed a significant (P<0.001) suppressive effect against both refractive and AL changes in the murine model. 7.5 mg/day of crocetin, which is the equivalent dosage to the animal experiment, was administered in the clinical trial. Two participants dropped out and 67 children completed this trial. The change of SER (D) in the placebo group, -0.41±0.05 (mean±standard deviation), was significantly greater than that in the crocetin group, -0.33±0.05 (P=0.049). The AL elongation (mm) in the placebo group, 0.21±0.02, was significantly greater than that in the placebo group, 0.18±0.02 (P=0.046). Interpretation: Dietary crocetin showed a suppressive effect of myopia progression in children. Trial Registration Number: This trial was also registered by Japic Clinical Trials Information with the registration number JapicCTI-173777. Funding: This study was supported by ROHTO Pharmaceutical Co., Tsubota Laboratory Inc., and Specified contribution from Keio University. Declaration of Interest: The current study was financially supported from ROHTO Pharmaceutical Co.,Ltd., Tsubota Laboratory, Inc., and the specified contribution from Keio University. Patents have been registered for the therapeutic effects of crocetin (patent application no. 2017-210596 by Tsubota Laboratory, Inc. and Rohto Pharmaceutical Co., Ltd.) and applied for the design of the mouse eyeglass by Tsubota Laboratory, Inc. (patent application no. 2017-41349). Ethical Approval: This trial was approved by the institutional review board of Keio University School of Medicine (approval no. 20180079) and Medical Corporation Heishinkai OPHAC Hospital Ethical Review Committee (approval no. 1011PC). All procedures were performed in accordance with the National Institutes of Health (NIH) guidelines for work with laboratory animals and the Association for Research in Vision and Ophthalmology (ARVO) statement for the Use of Animals in Ophthalmic and Vision Research, and were approved by the Institutional Animal Care and Use Committee at Keio University (registration no.3930).

Automated classification of dry eye type analyzing interference fringe color images of tear film using machine learning techniques

The unstable balance in secretions of lipids and aqueous fluid to tear film is a significant cause of dry eye disease (DED). Arita et al. demonstrated a simple but very effective method that classifies dry eye types to the aqueous deficient dry eye (ADDE) and the evaporative dry eye (EDE) by focusing on the dry eye type-unique appearances of interference fringe colors and patterns of tear films. We thought this simple classification is very helpful for diagnoses and treatments. However, diagnostic bias by unskilled observers remains an issue to be solved.&#x0D; The artificial intelligence (AI)-based support for diagnosis is one of the hottest topics in the field of ophthalmology research. We expected that the AI-based model would reduce bias in DED-type diagnoses. Many studies have been reported targeting retinal diseases like age-related macular degeneration and/or diabetic retinopathy. Most of the works established AI-based predicting models using images taken by fundus cameras and/or optical coherence tomography (OCT) devices to capture disease-related structural disorders. In contrast, the interference fringes dynamically change the colors and patterns spatiotemporally. To the best of our knowledge, there is no AI-based model studied for distinguishing ADDE and EDE using interference fringe images. However, an AI-based study classifying the condition of the tear lipid layer by analyzing the textures of interference fringes compared to the device-unique grades has been reported. This suggested the possibility of using the unstructured characteristics, such as colors and/or complexities of interference fringes, as the numerical image features when building AI-based prediction models. In this study, we first examined several types of image characteristics extracted from the colors and patterns of fringes to obtain effective image features for the DED-type classification. We then evaluated whether the AI-based models would have sufficient abilities for this type of prediction by comparing their diagnoses with those made by an ophthalmologist skilled in this classification (the founder of this type classification).

This Issue of ACTA

This Issue of ACTA

Inhibitory effect of bromfenac sodium hydrate ophthalmic solution on alkali burn induced-corneal neovascularization in rats

Objective To investigate the inhibitory effect of bromfenac sodium hydrate ophthalmic solution on corneal neovascularization (CNV) induced by alkali burn. Methods A total of 192 specific pathogen free (SPF) degree adult male Sprague-Dawley (SD) rats were used in this study.One hundred and seventy-two rats were chosen to establish CNV model with alkali burn in the right eyes.Following alkali burn, rats were randomly divided into CNV group, model control group, bromfenac sodium group and fluorometholone group, with 43 rats (43 eyes) in each group.Another 20 rats (40 eyes) served as normal control group.One day after modeling, the model control group, bromfenac sodium group and fluorometholone group received phosphate buffer saline (PBS), bromfenac sodium hydrate ophthalmic solution and 0.1% fluorometholone eye drops, respectively.The state of cornea and anterior chamber and the growth of CNV of rats in each group were observed by slit-lamp microscope every day after modeling.At 1, 3, 7, 14, 21 and 28 days after modeling, the anterior segment photos of the experimental eyes were captured, and the percent of cornea areas covered by CNV was calculated.At 7, 14 and 28 days after modeling, the eye tissue sections were stained with hematoxylin and eosin staining and immunohistochemistry staining to evaluate the expressions of CD45 and VEGF-A.Real-time quantitative PCR and enzyme-linked immunosorbent assay (ELISA) were used to detect the expression of COX-2 and VEGF mRNA and protein level.The use and care of the animals complied with the Statement of the Association for Research in Vision and Ophthalmology(ARVO). Results Each model group showed corneal edema and opacification 1 day after modeling.The corneal edema was aggravated 7 days after modeling.On the 14th day after modeling, the degree of corneal opacity and edema decreased gradually.On the 28th day after modeling, leucoma was observed in CNV group and model control group, and nebula was observed in bromfenac sodium group and fluorometholone group.At 7, 14, 21 and 28 days after modeling, the percentages of CNV areas in bromfenac sodium group and fluorometholone group were significantly lower than those in CNV group and model control group (all at P 0.05). On the 7th day after modeling, the thinning of corneal epithelial layer, edema and arrangement disorder of stroma layer were observed, and the expression of VEGF-A was positive in all model groups; a small amount of CD45 positive inflammatory cell infiltrations were observed in CNV group and model control group.On the 14th and 28th day after modeling, CNV was seen in the center of cornea in CNV group and model control group; the epithelial keratosis and reduction of corneal edema were seen in each group, and no inflammatory cell infiltration was observed in each group.On the 7th day after modeling, the expressions of COX-2 and VEGF mRNA in CNV group and model control group were significantly higher than those in normal control group, bromfenac sodium group and fluorometholone group (all at P<0.05), the expressions of COX-2 and VEGF protein in bromfenac sodium group were significantly lower than those in CNV group (all at P<0.05). The corneal perforation rate in model control group and bromfenac sodium group was 10% (1 case in 10 rats). The corneal perforation rate in fluorometholone group was 30% (3 cases in 10 rats). In each model group, 10% to 30% rats had hyphema. Conclusions Bromfenac sodium hydrate ophthalmic solution can inhibit the formation and growth of CNV after alkali burn in rats.This effect may be mediated by regulating COX-2 expression, reducing inflammation and inhibiting VEGF production. Key words: Corneal neovascularization; Alkali burn; Bromfenac sodium; Cyclooxygenase-2

Retinal Organ Cultures as Alternative Research Models.

Ex vivo organ cultures represent unique research models, as they combine the advantages of cell cultures with those of animal models. Being able to mimic in vivo situations through the use of organ cultures provides an excellent opportunity to investigate cellular processes, molecular pathways and cell-cell interactions, as well as structural and synaptic organisation. Human and animal organ cultures are now well established and comprise sensitive, easy-to-manipulate experimental systems that raise minimal ethical concerns. The eye, in particular, is a very complex organ that is not easy to reproduce in vitro. However, a lot of research has been dedicated to the development of suitable ocular organ cultures. This review covers the various ex vivo retinal organ culture systems available for use in ophthalmology research and compares them with commonly used animal models. In particular, bovine and porcine retinal organ culture systems are described, because the size, anatomy, physiology and vessel morphology of bovine and porcine eyes are similar to the human eye in an undisputed way, thus making them good models. In addition, these animals are widely used by the food industry and the eyes are considered surplus material. A short overview of murine, rat, rabbit, cat, canine and simian retinal organ cultures is also provided.

Technology for detection and prevention of consequences of hybrid war syndrome

The work is devoted to the development and implementation of detection technology, complex analysis, treatment, rehabilitation and prevention of hybrid war syndrome (as a characteristic syndrome of crisis situations). For the first time, the "Hybrid War Syndrome", as a characteristic syndrome of crisis situations (wars, catastrophes, emergencies) was systematically investigated and described, and the system of differential diagnostics was developed. For the first time were developed and described the mechanisms of development and models of the formation of PTSD in hybrid warfare, as part of the hybrid war syndrome. The peculiarities of information and cognitive traumatism PTSD etiology during hybrid war were investigated. Ophthalmic pathologies characteristic to the hybrid war syndrome and the oculomotor changes characteristic to the persons with PTSD have been identified and studied. Methods and means of hardware (instrumental) objective detection and diagnostics of PTSD were developed. For the first time the technology of diagnostics, complex analysis, innovative treatment, rehabilitation and prophylaxis of formed in conditions of hybrid war PTSD and hybrid war syndrome in general was developed with the use of instrumental techniques, which makes the process of detection, diagnosis and treatment significantly more objective. Developed and implemented. On the basis of the developed technology of objective instrumental detection, diagnosis, treatment and rehabilitation of the hybrid war syndrome was created a system of diagnostics, treatment and rehabilitation of formed under conditions of hybrid war PTSD and hybrid war syndrome in general, in the National Military Medical Clinical Center "Chief Military Clinical Hospital". A complex system for the prevention of crisis syndromes has been created, with the development of techniques for "escorting" the members of the armed forces at all stages (before, during, after) of a crisis situation, which is based on objective ophthalmological instrumental research methods.

1H NMR Spectroscopy Characterization of Porcine Vitreous Humor in Physiological and Photoreceptor Degeneration Conditions.

Qualitative and quantitative analysis of vitreous humor (VH) is important to discriminate between physiological and pathological conditions and may be particularly helpful when using animal models for ophthalmologic research. The aim of the present study was to investigate the physiological qualitative/quantitative composition of the VH of the standard pig using a metabolomics approach based on 1H nuclear magnetic resonance (NMR) spectroscopy. A secondary aim was the characterization of the VH of the porcine model of photoreceptor degeneration induced with iodoacetic acid (IAA), widely used in the biomedical field, and comparison with the physiological one. VH samples were collected from 30 pigs (17 in the physiological condition and 13 treated with IAA) upon vitrectomy and analyzed by means of 1H NMR spectroscopy for characterization. On all analyzed samples, 40 molecules could be identified and quantified, with lactate being the most abundant in both physiological and photoreceptor degeneration conditions. Upon comparison, only 17 molecules showed statistical differences: In the IAA group, glucose and glutamine increased, while lactate, 4-amynobutyrate, hypoxanthine, dicarboxylic acids (succinate and fumarate), amino acids with their derivatives (creatine, alanine, valine, lysine, leucine, glycine, taurine, and isoleucine), and choline with its precursor sn-glycero-3-phosphocholine decreased. The results validate the metabolic impairment determined by glycolysis inhibition upon systemic IAA administration. In conclusion, this work represents the first characterization of the porcine VH metabolome in physiological conditions and provides additional information for the characterization and refinement of the IAA-induced photoreceptor degeneration model.

A technical protocol for an experimental ex vivo model using arterially perfused porcine eyes

Ex vivo ocular perfused models have been described in the past and were applied in different mammalian species as platforms to test drug delivery systems and surgical techniques. However, reproduction of those methods is challenging because extensive and precise description of the protocols used is lacking. In this technical paper we provide a detailed description of all the steps to be followed from the enucleation of porcine eyes to cannulation of the ophthalmic artery and perfusion. This model can contribute to the reduction of use of living animals in ophthalmology research, whereas as opposed to in vitro models, it preserves tissue complexity and integrity.

Proceedings of the Association for Research in Vision and Ophthalmology and Champalimaud Foundation Ocular Oncogenesis and Oncology Conference.

The 2018 Ocular Oncogenesis and Oncology Conference was held through a partnership of the Association for Research in Vision and Ophthalmology (ARVO) and the Champalimaud Foundation. Twenty-one experts from international ocular oncology centers, from the Champalimaud Clinical Centre and the Champalimaud Foundation Cancer Research Program, and from patient advocacy organizations, delivered lectures on subjects that ranged from global ocular oncology, to basic research in mechanisms of ocular malignancy, to clinical research in ocular cancers, and to anticipated future developments in the area. The scientific program of the conference covered a broad range of ocular tumors—including uveal melanoma, retinoblastoma, ocular surface tumors, and adnexal and intraocular lymphomas—and pathogenesis and management were deliberated in the context of the broader systemic cancer discipline. In considering the latest basic and clinical research developments in ocular oncogenesis and oncology, and providing the opportunity for cross-talk between ocular cancer biologists, systemic cancer biologists, ocular oncologists, systemic oncologists, patients, and patient advocates, the forum generated new knowledge and novel insights for the field. This report summarizes the content of the invited talks at the 2018 ARVO-Champalimaud Foundation Ocular Oncogenesis and Oncology Conference.

RNA-sequencing in ophthalmology research: considerations for experimental design and analysis.

High-throughput, massively parallel sequence analysis has revolutionized the way that researchers design and execute scientific investigations. Vast amounts of sequence data can be generated in short periods of time. Regarding ophthalmology and vision research, extensive interrogation of patient samples for underlying causative DNA mutations has resulted in the discovery of many new genes relevant to eye disease. However, such analysis remains functionally limited. RNA-sequencing accurately snapshots thousands of genes, capturing many subtypes of RNA molecules, and has become the gold standard for transcriptome gene expression quantification. RNA-sequencing has the potential to advance our understanding of eye development and disease; it can reveal new candidates to improve our molecular diagnosis rates and highlight therapeutic targets for intervention. But with a wide range of applications, the design of such experiments can be problematic, no single optimal pipeline exists, and therefore, several considerations must be undertaken for optimal study design. We review the key steps involved in RNA-sequencing experimental design and the downstream bioinformatic pipelines used for differential gene expression. We provide guidance on the application of RNA-sequencing to ophthalmology and sources of open-access eye-related data sets.

The use of patient-reported outcome research in modern ophthalmology: impact on clinical trials and routine clinical practice.

This review article considers the rising demand for patient-reported outcome measures (PROMs) in modern ophthalmic research and clinical practice. We review what PROMs are, how they are developed and chosen for use, and how their quality can be critically appraised. We outline the progress made to develop PROMs in each clinical subspecialty. We highlight recent examples of the use of PROMs as secondary outcome measures in randomized controlled clinical trials and consider the impact they have had. With increasing interest in using PROMs as primary outcome measures, particularly where interventions have been found to be of equivalent efficacy by traditional outcome metrics, we highlight the importance of instrument precision in permitting smaller sample sizes to be recruited. Our review finds that while there has been considerable progress in PROM development, particularly in cataract, glaucoma, medical retina, and low vision, there is a paucity of useful tools for less common ophthalmic conditions. Development and validation of item banks, administered using computer adaptive testing, has been proposed as a solution to overcome many of the traditional limitations of PROMs, but further work will be needed to examine their acceptability to patients, clinicians, and investigators.

Ophthalmology research in the UK's National Health Service: the structure and performance of the NIHR's Ophthalmology research portfolio.

To report on the composition and performance of the portfolio of Ophthalmology research studies in the United Kingdom's National Institute for Health Research (NIHR) Clinical Research Network (UK CRN). Ophthalmology studies open to recruitment between 1 April 2010 and 31 March 2018 were classified by: sub-specialty, participant age, gender of Chief Investigator, involvement of genetic investigations, commercial/ non-commercial, interventional/observational design. Frequency distributions for each covariate and temporal variation in recruitment to time and target were analysed. Over 8 years, 137,377 participants were recruited (average of 15,457 participants/year; range: 5485-32,573) with growth by year in proportion of commercial studies and hospital participation in England (76% in 2017/18). Fourteen percent of studies had a genetic component and most studies (82%) included only adults. The majority of studies (41%) enrolled patients with retinal diseases, followed by glaucoma (17%), anterior segment and cataract (13%), and ocular inflammation (6%). Overall, 68% of non-commercial studies and 55% of commercial studies recruited within the anticipated time set by the study and also recruited to or exceeded the target number of participants. High levels of clinical research activity, growth and improved performance have been observed in Ophthalmology in UK over the past 8 years. Some sub-specialties that carry substantial morbidity and a very high burden on NHS services are underrepresented and deserve more patient-centred research. Yet the NIHR and its CRN Ophthalmology National Specialty Group has enabled key steps in achieving the goal of embedding research into every day clinical care.

Retinal Cryo-sections, Whole-Mounts, and Hypotonic Isolated Vasculature Preparations for Immunohistochemical Visualization of Microvascular Pericytes.

Retinal pericytes play an important role in many diseases of the eye. Immunohistochemical staining techniques of retinal vessels and microvascular pericytes are central to ophthalmological research. It is vital to choose an appropriate method of visualizing the microvascular pericytes. We describe retinal microvascular pericyte immunohistochemical staining in cryo-sections, whole-mounts, and hypotonic isolated vasculature using antibodies for platelet-derived growth factor receptor β (PDGFRβ) and nerve/glial antigen 2 (NG2). This allows us to highlight advantages and shortcomings of each of the three tissue preparations for the visualization of the retinal microvascular pericytes. Cryo-sections provide transsectional visualization of all retinal layers but contain only a few occasional transverse cuts of the microvasculature. Whole-mount provides an overview of the entire retinal vasculature, but visualization of the microvasculature can be troublesome. Hypotonic isolation provides a method to visualize the entire retinal vasculature by the removal of neuronal cells, but this makes the tissue very fragile.

The fate of abstracts presented at international ophthalmology meetings: 2- and 5-year publication rates.

To investigate the 2- and 5-year publication rates of abstracts presented at major international ophthalmology meetings. We analyzed a random selection of 20% of free papers and posters presented at the 2010 meeting of the Association for Research in Vision and Ophthalmology, the American Academy of Ophthalmology, the European Association for Vision and Eye Research, the Asia-Pacific Academy of Ophthalmology, and the 2009 European Society of Ophthalmology meeting. The PubMed (MEDLINE) database was searched to identify matching journal articles. Data collection included: topic, geographic origin, presentation type, publication status, and impact factor. A multivariate logistic regression model was used to assess odds of publication and impact factor. Our analysis included 1742 research abstracts. The overall 2- and 5-year publication rates were 33.3% (n = 579) and 47.2% (n = 823), respectively. The highest publication rates were found for Association for Research in Vision and Ophthalmology (36.1% and 51.9%, p < 0.0001), paper presentations (44.5% and 60.5%, p < 0.0001), researches from Oceania (35.8% and 57.1%, p < 0.05) and North America (36.2% and 50.5%, p < 0.05), and Basic science studies (44% and 60.3%, p < 0.01). After adjustments, higher odds of publication were shown by the Association for Research in Vision and Ophthalmology and the American Academy of Ophthalmology meetings (p < 0.0001), papers (p < 0.0001), and Basic science (p < 0.05). The median impact factor was 3.20 (interquartile range = 1.90-3.40). Less than half of abstracts presented at the major ophthalmology meetings reach publication within 5 years of their initial presentation. Professionals attending meetings may consider adopting a more critical approach to the preliminary results reported in presented abstracts. Increasing publication rates and reducing potential publication bias is of interest.

Behavioral Assessment of Vision in Pigs.

Swine (Sus scrofa) are often the 'gold standard' laboratory animal for ophthalmology research due to the anatomic and physiologic similarities between the porcine and human eye and retina. Despite the importance of this model, few tools for behavioral vision assessment in pigs are available. The aim of this study was to identify and validate a feasible and reproducible behavioral test to assess vision in a pig model of photoreceptor degeneration. In addition, a robust behavioral test will reduce stress and enhance enrichment by allowing animals opportunities for environmental exploration and by reducing the number of invasive experimental procedures. Two distinct behavioral approaches were tested: the obstacle-course test and temperament test. In the obstacle-course test, pigs were challenged (after an initial training period) to navigate a 10-object obstacle course; time and the number of collisions with the objects were recorded. In the temperament test, the time needed for pigs to complete 3 different tasks (human-approach, novel-object, and open-door tests) was recorded. The obstacle-course test revealed significant differences in time and number of collisions between swine with vision impairment and control animals, and the training period proved to be pivotal to avoid bias due to individual animal characteristics. In contrast, the temperament test was not altered by vision impairment but was validated to measure stress and behavioral alterations in laboratory pigs undergoing experimental procedures, thus achieving marked refinement of the study.