bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of intra‐cellular metabolism by time‐resolved autofluorescence
Authors: SCHWEITZER D 
Published: August 2012

AbstractPurpose Changes in metabolism are first signs of pathological processes. The extra‐cellular metabolism can be estimated by parameters of microcirculation. The fluorescence of endogenous fluorophores characterizes the intracellular metabolism. Besides of NADH and FAD which act as electron transporter in the respiratory chain, several other fluorophores like lipofuscin and advanced glycation end products, or collagen and elastin form the autofluorescence of the fundus.Methods The influence of single fluorophores can be determined combining measurements of fluorescence decay after pulse excitation with spectral measurements. Based on fluorescence and lifetime measurements on isolated fluorophores and separated anatomical structures of porcine eyes, a laser scanner ophthalmoscope was modified for Fluorescence Lifetime Imaging Ophthalmoscopy (FLIO). The eye‐ground of human eyes is excited at 448 nm (70 ps FWHM, 80 MHz) and the fluorescence is detected in 2 spectral channels (490‐560 nm and 560‐700 nm) in TCSPC in 1024 time channels.Results A certain relation was found between exponents of triple‐exponential fit and anatomical structures. The lifetime tau 1 (about 70 ps) corresponds to the fluorescence in retinal pigment epithelium. The lifetime tau 2 (about 400 ps) originates from layers in the neuronal retina (receptors, bi‐polares, ganglion cells). The lifetime tau 3 (about 3ns) is determined by connective tissue in the nerve fiber layer and to a certain degree by the fluorescence of the crystalline lens, too.Conclusion The changes of tau 2 in the short wavelength spectral range which were found in the neuronal retina for diabetic patients having no signs of diabetic retinopathy,are interpretable as a loss of free NADH and a shift to protein‐bound NADH.
Commercial interest
Retinal oximetry technology
Authors: HARDARSON S 
Published: August 2012

AbstractPurpose Disturbances in retinal oxygenation are believed to be involved in several eye diseases, among them retinal vessel occlusions, diabetic retinopathy and possibly glaucoma and age‐related macular degeneration. The technology to reliably and non‐invasively measure retinal oxygenation is emerging after decades of development.Methods Non‐invasive retinal oximetry utilises the fact that the colour of blood changes as oxygen saturation changes. The most reliable measurements can be obtained from the larger retinal vessels, while measurements of retinal capillaries need further development. Several instruments have been built for non‐invasive oximetry. They measure light absorbance of retinal blood vessels at two or more wavelengths and use the result to calculate retinal vessel oxygen saturation.Results Several research groups have shown that their instruments are sensitive to changes in retinal vessel oxygen saturation and that the measurements are reproducible. Oximetry has successfully been used to detect differences in retinal oxygenation in many diseases as well as responses to treatment or provocation tests. Accurate calibration is, however, difficult.Conclusion The current retinal oximetry technology can reliably be used to measure changes in retinal vessel oxygen saturation in the same eye with time. Oximetry can also easily measure differences in means between groups. Further development is needed to increase the accuracy of single measurements.
Commercial interest
New developments in optical coherence tomography
Authors: SCHMETTERER L 
Published: August 2012

AbstractPurpose Optical coherence tomography (OCT) has become a standard tool in imaging the retina, the optic nerve head and the anterior segment of the eye. In the recent years much effort was directed towards improving the acquisition speed and the resolution of the technique. In addition, functional extensions of the technique were presented.Methods Ultrahigh‐speed swept sources can be used to improve A‐scan rate in OCT, a technique also called optical frequency domain imaging. Increasing the bandwidth can improve longitudinal resolution in OCT and longer wavelengths in the near infrared improve penetration depth. Adaptive optics OCT improves transversal resolution. Functional extensions include measurement of blood flow and oxygenation.Results High‐speed imaging allows for three‐dimensional imaging of the posterior and anterior segment of the eye. Using adaptive optics volumetric cellular resolution imaging becomes possible. 1050 nm OCT allows for visualization of the sclera and therefore measurement of choroidal thickness. Functional OCT provides insight into retinal metabolism.Conclusion Improvements and extensions of OCT have been reported that will find its way into clinical routine. This is expected to result in improved understanding of retinal and optic nerve head disease.
Expression of lysophosphatidic acid, autotaxin and acylglycerol kinase
Authors: ABU EL ASRAR A , MOHAMMAD G , NAWAZ MI , SIDDIQUEI M , KANGAVE D , OPDENAKKER G 
Published: August 2012

AbstractPurpose To measure the levels of LPA and LPA‐producing enzymes, autotaxin (ATX) and acylglycerol kinase (AGK) in the vitreous fluid from patients with proliferative diabetic retinopathy (PDR) and to correlate their levels with clinical disease activity and the level of vascular endothelial growth factor (VEGF). In addition, we examined the expression of ATX, AGK and VEGFR‐2 in the retinas of diabetic rats.Methods Vitreous samples from 42 PDR and 35 nondiabetic patients were studied by enzyme‐linked immunosorbent assay. Vitreous samples and retinas of rats were examined by Western blot analysis.Results VEGF, LPA and AGK levels in vitreous samples from PDR patients were significantly higher than those in control patients without diabetes (p<0.001 for all comparisons). ATX levels in PDR with active neovascularization and inactive PDR were significantly lower than those in nondiabetic patients (p=0.045). Mean VEGF and AGK levels in PDR with active neovascularization were significantly higher than those in inactive PDR and nondiabetic patients (p<0.001 for both comparisons). A significant correlation was observed between levels of VEGF and levels of AGK in PDR patients (r=0.954, p<0.001). Western blot analysis revealed a significant increase in the expression of AGK and VEGFR‐2 in vitreous samples and the retinas of diabetic rats compared to nondiabetic controls, whereas ATX was significantly downregulated.Conclusion ATX‐AGK‐LPA signaling axis might be an important player in the development and progression of diabetic retinopathy.
Retinal pathways involved in the control of eye growth and myopia
Authors: MORGAN IAN 
Published: August 2012

AbstractPurpose To integrate information from studies on gene expression in animal mpdels and from genetic studies on human myopia to define the pathways which are involved in the development of myopiaMethods A literature search of studies on gene expression in animal models of myopia and human genetic studies was carried out using the Medline databaseResults Human genetic studies identify two clusters of mutations which are involved in human high myopia. One involves genes which affect photoreceptor and ON‐bipolar cell function in the outer retina. These mutations are associated with congenital stationary night blindness. A second cluster involves genes involved in extracellular matrix structure and function, which may be important in the sclera, which changes markedly during the development of myopia. ON‐bipolar cells play a major role in the control of dopamine release in the retina. Other evidence supports a role for dopamine in the control of eye growth, which suggests a plausible pathway linking the genes involved in the outer retina to control of eye growth. However, the down‐stream effects of changes in dpoamine release are not well‐characterised studies. However, animal studies have suggested that changes in the expression of the early intermediate gene ZENK and changes in glucagon release within the retina may play a roleConclusion Huamn genetic studies and studies of changes in gene expression in animal models of myopia provide a consistent but still incomplete picture of the pathways involved in the control of eye growth. Further studies on these pathways are of particular importance given that they implicate retinal dopamine release , which links them to the epidemiological evidence that bright light‐ induced dopamine release can prevent the development of myopia in humans
Retinal ganglion cell differentiation and protection using neuronally differentiated human dental pulp stem cells
Authors: HONG S 
Published: August 2012

AbstractPurpose To investigate whether the neuronally differentiated human dental pulp stem cells (NDhDPSCs) can differentiate into retinal ganglion cells (RGCs) and whether the NDhDPSCs can protect primary mouse RGCs against oxidative stress injury.Methods Human dental pulp stem cells were harvested and neuronally differentiated using various conditioned media. By immunohistochemistry, western immunoblots, and real‐time RT‐PCR, their cellular characteristics were evaluated and the best culture condition was determined for differentiation into RGC/glia‐like NDhDPSCs. Regarding glial‐like NDhDPSCs, they were cocultured with primary mouse RGCs under oxidative stress injury.Results In specialized conditioned media, human dental pulp stem cells were differentiated into RGC/glia‐like NDhDPSCs. They expressed RGC/glia‐specfic markers as well as neuronal stem cell markers. When the glia‐like NDhDPSCs were indirectly cocultured with primary mouse RGCs, they protect the RGCs against oxidative stress injury as determined by TUNEL assay.Conclusion The human dental pulp stem cells may differentiate into RGC‐like NDhDPSCs in a suitable culture condition. And the glia‐like NDhDPSCs can protect primary mouse RGCs against oxidative stress injury in vitro.
Intermembranaceous spaces of human optic nerve intracanal part
Authors: HUSEVA YA , DENISOV SD 
Published: August 2012

AbstractPurpose Purpose of research ‐ to reveal laws of structure and distribution of intermembranaceous spaces of optic nerve intracanal part.Methods 43 bone blocks including optic canal with located in them membranes (dura, arachnoidea, pia), ophthalmic artery of people aged from 26 weeks of prenatal development till 75 years were histologically studied. The structure of optic nerve membranes and intermembranaceous spaces in the cranial, transitive and orbital compartments of optic canal were established. The received data were compared to optic canal MRI results of 27 patients (54 optic canals) aged from 2 months till 75 years on the "VISTA" МР‐tomograph 1 T intensity of magnetic field.Results Wide, uniform, continuous intermembranaceous spaces are characteristic for optic canal cranial compartment, medially and laterally of optic nerve they are more expressed. In optic canal orbital compartment subdural space is the narrowest, non‐uniform on MRI and bone blocks research. The subarahnoidal space is most expressed in cranial compartment of canal laterally of optic nerve above of it, and on MRI medially of nerve it is absent or narrow, non‐uniform, faltering crack (the similar data is received on histologic research). In transitive optic canal compartment there are separate fragments of subarahnoidal space or its absence in different directions from optic nerve (according to histologic research ‐ above of nerve). In orbital compartment this space in the most cases is closed above and below of optic nerve (by results of research of bone blocks ‐ on all circle of optic nerve).Conclusion The laws of intermembranaceous space structure and their distributions in optic canal were revealed. MRI was effective method in study of intermembranaceous spaces of optic nerve intracanal part.
3D blood vessels segmentation from optical coherence tomography
Authors: GUIMARAES P , RODRIGUES P , BERNARDES R , SERRANHO P 
Published: August 2012

AbstractPurpose To compute the 3D retinal vascular network, from standard high‐definition optical coherence tomography (HD‐OCT) data.Methods Abnormal retinal vascular patterns were shown to be related to retinal and cardiac diseases. Studies have been performed using 2D fundus images. However, the obtained measurements may suffer from missing depth information for improved quantitative accuracy. In this work we resorted to Cirrus HD‐OCT data (Carl Zeiss Meditec, Inc., Dublin, CA, USA) to scan the human macula. Our approach to obtain vessel positioning (depth‐wise) takes advantage of the 2D automatic vessel segmentation of an OCT fundus image. To locate vessels in depth, we compare A‐scans where in the fundus image no vessels were detected to neighbor A‐scans containing vessels. Hence, we are able to identify the location of particular landmarks that characterize the presence of a vessel, such as, the hyper‐reflectivity and the shadowing effect (due to the light absorption by blood).Results Our algorithm is able to locate both above‐mentioned vessel markers (hyper‐reflective region and shadow). Preliminary data shows promising results. Both markers present good robustness and coherence, as demonstrated by the smoothness of vessels across different B‐scans and the possibility to discriminate between different depth paths of crossing vessels.Conclusion The findings suggest the possibility to compute the 3D vascular network, noninvasively, using a standard high‐definition OCT. Additionally, accounting for vessel depth will lead to improved measurements of retinal vascular network properties and therefore to possible better correlations between its shape, location, and disease status.
Follow‐up study of MEWDS using adaptive optics retinal imaging
Authors: GOCHO‐NAKASHIMA K , AUDO I , MOHAND‐SAID S , KAMEYA S , YAMAKI K , TAKAHASHI H , SAHEL JA , PAQUES M 
Published: August 2012

AbstractPurpose To study the effects of pathological damage in cone photoreceptor outer segments (OS) on the visibility of cones in adaptive optics (AO) images.Methods Four patients with multiple evanescent white dot syndrome (MEWDS) underwent multimodal retinal imaging using optical coherence tomography (OCT), scanning laser ophthalmoscopy (SLO). AO images were acquired with a field of 4 x 4 deg at eccentricities ranging from 0 to 8 deg from fovea using an infrared flood‐illumination AO camera (rtx1, Imagine Eyes, France). Cone phoreceptor density was measured and analyzed in comparison to the findings from the other imaging modalities. The procedure was repeated at a follow‐up visit after one month. One patient had 3 additional follow‐up examinations over a 10‐month time.Results OCT images showed irregularities and disruptions in the OS tip line. Local thinning of the OS layer was observed in several areas of the macula. AO images revealed marked decreases in the density of detectable cones in the exact same regions. The measured cone density was superior to 30000 cells per mm2 in the areas of normal OS length and dropped to less than 10000 cells per mm2 in the regions of shortened OS. The locations of cone mosaic defects in the AO images also corresponded with hypo‐fluorescent areas observed in the late phase of ICG angiography. During clinical recovery, the progressive return of the IS/OS and the OS tip lines to a normal layered structure in OCT images was correlated to an increase in cone density in AO images.Conclusion AO imaging facilitates detection and monitoring of damage and recovery of the photoreceptor OS during MEWDS. The visibility of cones in AO images seems to be strongly dependent on OS structure and length.
Assessment of different methods for inter‐individual registration of OCT topography for statistical analysis
Authors: HALDAR S , DAVIES N 
Published: August 2012

AbstractPurpose Assessment of OCT topography is subjective. A statistical method of analysis would be helpful to aid interpretation. This requires the generation of accurate normative topography which in turn requires accurate alignment of normal OCTs. This study assesses 9 methods of alignment.Methods Normal topography maps were exported from a spectral domain OCT system. Code was written to perform image registration using different methods: User selection of foveal centre, cross‐correlation to a difference of two Gaussian macula template, finding of the thinnest central point and automatic fovea‐finding using Gaussian convolution and centroiding for the red, green and blue channels of the image respectively.Results Data from 127 left and 110 right eyes were analysed. Mean and total standard deviation across the central 400x400 pixels of the aligned maps were calculated. The lowest standard deviation was achieved by the cross‐correlation method (38.9 microns), followed by the blue channel centroiding method (40.4 microns), the thinnest central point (40.5 microns) and the user‐selected foveal centre (40.6 microns). Convolution with a Gaussian to identify the fovea produced the worst results with mean SD of 49.9‐64.8 microns.Conclusion Cross‐correlation with a difference of two Gaussian macula template appears superior for inter‐individual topography registration in OCT in comparison with fovea‐finding methods. Blue centroid and thinnest point were the best other methods. The cross‐correlation technique will lead to the most accurate normal maps for statistical comparison with data from pathological OCT topography.
Atrophic areas and/with neovascular AMD. Characteristics, evolution of atrophic lesions associated to neovascular AMD treated by series of 3 Ranibizumab IVT protocol, 4 years follow‐up
Authors: GONZALEZ C 
Published: August 2012

AbstractPurpose To evaluate atrophic areas characteristics, at the first time, their change, evolution and correlation or no with and during the follow‐up of neovascular AMD treatment by series of 3 Ranibizumab IVTMethods 102 eyes of 91 patients, 28 men, 63 women, with retrofoveolar neovascularisation complicating AMD. Atrophic areas were evaluated by autofluorescence imaging Spectralis (in particular with region finder software), OCT (notably choriocapillary depth), FA, ICG. We evaluate the size, characteristics, topography of the lesions, their growth way. The areas themselves, their edge and rim were considered and evaluated. Each element was studied, compared cut to cut and time to time to itself and to each other data, every 2 months. The impact of AMD and /or this treatment protocol on the evolution of atrophic areas is also valuate.Results VA improved in 85% cases, stabilized in 15%. AF imaging and their region finder analyze were the main elements of the atrophic lesions’ study. The surface of the atrophic area grows by 17%, the edge changes in 20%. Speed growth was in average 1,15mm2/year. At OCT, thickness of photoreceptor, pigment epithelium layer diminished about 25% and 35% at the area’s edge. Choriocapillary depth values, FA and ICG data were mainly significative in the large atrophic areas and less than AF indications. This protocol has a little impact on the evolution of atrophic areas, apparently less than monthly IVT, and the same as AMD by itself.Conclusion The study of atrophic process and its progression is a main question in the AMD follow –up, the evaluation of the protocol treatments and their safety too.
Trends in anterior segment surgery: what is coming?
Authors: ALIO SANZ J 
Published: August 2012

AbstractAnterior segment surgery has experienced a huge development in the last 25 years. Presently, in spite of this accelerated development, new technologies have emerged that have impacted considerably the surgery of the crystalline lens, the cornea and its pathologies. Corneal blindness, corneal debilitating diseases (corneal ectatic disease), corneal opacities, post infectious or traumatic problems and complication of cataract surgery has increased the rate of performance of corneal surgery, with corneal blindness still being a worldwide problem. Concerning the crystalline lens, cataract surgery is the most widely performed surgical procedure in the human being, and every step forward in this surgery affects millions of people around the world every year. Corneal surgery has been opened to a new stage of development thanks to the introduction of femtosecond laser technology, corneal crosslinking procedures, better knowledge of corneal biomechanics, improvements in corneal transplantation, development of corneal regenerating techniques, new antiinflammatory and immunological medication and a better knowledge about the ocular surface biological behaviour. Crystalline lens and cataract surgery have experienced a major recent impact with the introduction of femtosecond lasers for cataract surgery, and the so‐called premium IOLs. Jointly, they represent a large step forward in the outcomes that are expected for cataract surgery, in which not only vision research is expected but also the spectacle independent condition for far and for near. Different models of accommodative lenses, multifocal lenses and other technologies have approached this refractive purpose. In this presentation the actual trends based on evidence based knowledge about the immediate evolution of corneal and crystalline lens surgery, the recent developments in the knowledge of the corneal diopter in normal and diseased conditions and the implementation that cataract surgery and IOL technology is undergoing today will be explained. The concept of eye modelling with modern customization of all these procedures through a global modern eye based on recent knowledge will be also outlined.
Perspectives for new treatments at Alcon ‐ part 1
Authors: RICH C 
Published: August 2012

AbstractThis presentation will give the audience an overview of how we identify a wide variety of potential products to develop and how we condense this list down to the final candidates that will establish our pipeline strategy for each year. This process is conducted across the 3 main franchises of Alcon: Pharmaceuticals, Surgical and Vision Care. This presentation will review products in development in the areas of Glaucoma, Anterior Segment and the Ocular Surface. In the area of Glaucoma we currently have several products that will be reviewed. This includes potential new chemical entities with novel mechanisms of action and combination products that have the IOP lowering power greater than a beta‐blocker without the risk of a beta‐blocker. In the area of anterior segment we have several exciting programs in development to meet the unmet medical need around cataract surgery healing and post‐operative infection. In the area of the ocular surface we have several projects in development for improved treatment in allergy (both nasal and ocular) and dry eye. In addition, as an extension of this area, we have projects for the treatment of acute otitis externa and antibacterial use during the peri‐operative placement of tympanostomy tubes.
Gullstrand (ECR‐CCRS‐2010‐01)
Authors: ROZEMA J 
Published: August 2012

AbstractPurpose To present the current status of the Project Gullstrand study, aimed at measuring a large amount of biometric and visual function data in multiple centers Europe‐wide.Results At the time of writing (29/5/2012) 630 subjects have been measured in 12 participating sites located in 6 countries. One site has already finished recruiting. In order to give all other sites, some of which started recruiting only a few weeks ago, the chance to reach the targeted number of 200 subjects per site, the recruitment period has been extended to 31 December 2012. Given the current progress rates in the different sites it is very likely that the recruitment targets will be met at this time.Conclusion The study is progressing well and is expected to reach its recruitment target by the end of the recruitment period.