bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is inhibition of VEGF165 sufficient to inhibit scar formation after trabeculectomy?
Authors: VAN BERGEN T , VAN DE VEIRE S , VANDEWALLE E , MOONS L , STALMANS I 
Published: September 2009

Abstract Purpose We have previously shown that VEGF plays a role in scar formation after glaucoma surgery and that inhibition of all VEGF‐isoforms by bevacizumab is able to reduce scar formation. This study was designed to elucidate the exact role of VEGF165 in scar formation after trabeculectomy. The effect of pegaptanib (Pfizer), which specifically blocks VEGF165, was investigated in vitro and in vivo. Methods The effect of pegaptanib on Tenon fibroblasts and HUVEC in vitro was determined using a WST‐1 proliferation assay. The effect of the aptamer was also investigated in vivo in a rabbit model for glaucoma surgery by studying angiogenesis, inflammation and collagen deposition. Results A dose‐dependent reduction of HUVEC proliferation was seen after pegaptanib administration in vitro (P<0.05 with a dose of at least 0,3 mg/ml). A concentration of 2 mg/ml pegaptanib was necessary to inhibit the proliferation of Tenon fibroblasts. The aptamer also significantly reduced blood vessel density 3 days after surgery in a rabbit model of trabeculectomy (P=0.001). There were no significant differences in inflammation and collagen deposition in the treated eyes compared to control. Conclusion Whereas HUVEC cells were inhibited by pegaptanib in a dose‐dependent way, Tenon fibroblasts were only inhibited at the highest dose. A single administration of pegaptanib at the time of trabeculectomy reduced postoperative angiogenesis, but not inflammation or collagen deposition. Further studies using repeated pegaptanib injections are necessary to investigate whether the lack of effect of pegaptanib on scarring was due to a shorter working time of pegaptanib compared to bevacizumab, or due to the difference in their effect on the various VEGF isoforms.
Relationship between IOP and age in the Salzburg‐Moorfields‐Collaborative Glaucoma Study
Authors: REITSAMER HA , HITZL W , WINTERSTELLER CH , HORNYKEWYCS K , ABRI S , GRABNER G 
Published: September 2009

Abstract Purpose To investigate the distribution of intraocular pressure in a population based survey in the county of Salzburg. Methods The SMCGS is a single‐center, prospective cohort study embedded into a government supported glaucoma blindness prevention program in Salzburg county, Austria. A complete ophthalmological examination including biomicroscopy of the optic nerve head, visual field testing, measurements of intraocular pressure, central corneal thickness and laser scanning topography of the optic disc was performed on 3650 subjects at the beginning of the study as well as at the five year follow‐up. Results The average age is 60.3 years (min: 40.04, max:93.9 years), IOP is 15.0 mmHg (min: 7, max: 32 mmHg) and the correlation coefficient between age and intraocular pressure is r = 0.005, p = 0.75 (95% CI ‐0.03 and 0.026). Also in the subgroups (people with normal findings, people with increased cup to disk ratio (C/D>0.45) and people with ocular hypertension (IOP>21mmHg) no significant correlation between age and intraocular was found. Conclusion In the past, numerous studies showed a correlation between age and intraocular pressure or at least reported a vague relationship between the two variables. Of all large scale studies only the blue mountain eye study and the Beijing eye study did not find a positive correlation between age and intraocular pressure (before correction for arterial pressure). In the population of Salzburg, age is an independent risk factor for glaucoma, independent of IOP and without correction of possible confounders.
Association between optic nerve head blood flow as assessed with Laser Doppler Flowmetry and mean arterial blood pressure in glaucoma, ocular hypertension and healthy control subjects
Authors: SCHMIDL D , HOMMER A , RESCH H , FUCHSJAEGER‐MAYRL G , GARHOFER G , VASS C , SCHMETTERER L 
Published: September 2009

Abstract Purpose It has been implicated that vascular dysregulation plays a role in the pathogenesis of primary open angle glaucoma (POAG). In the present study the association between optic nerve head blood flow as measured with laser Doppler flowmetry and ocular perfusion pressure in patients with treated and untreated POAG, patients with ocular hypertension and healthy control subjects was compared. Methods 136 patients with treated POAG, 116 patients with untreated POAG, 138 patients with ocular hypertension and 160 control subjects were included in the study. Optic nerve head blood flow was assessed using laser Doppler flowmetry. Ocular perfusion pressure was calculated based on measurement of IOP and systemic hemodynamics. Results Optic nerve head blood flow was significantly reduced in patients with glaucoma compared to patients with ocular hypertension and healthy subjects (p<0.01). However, no difference in optic nerve head blood flow between treated and untreated glaucoma patients was detected. The highest association between ocular perfusion pressure and optic nerve head blood flow was found in untreated glaucoma patients followed by ocular hypertensives and treated glaucoma patients. Conclusion The present study confirms evidence that optic nerve head blood flow is reduced in patients with POAG and patients with ocular hypertension. Correlation coefficients in the glaucoma groups and in the ocular hypertensives indicate a vascular dysregulation in these patients compared to healthy control subjects.
Vascular endothelial dysfunction in primary open angle glaucoma
Authors: CELLINI M , GIZZI C , STROBBE E , FAVARETTO E , FILIPPINI M , PALARETI G , CAMPOS EC 
Published: September 2009

Abstract Purpose Glaucomatous optic neuropathy (GON) is related not only to elevated intraocular pressure (IOP) but also to an insufficient ocular blood supply related to a vascular dysregulation. We evaluated peripheral vascular endothelial function in primary open‐angle glaucoma (POAG) with a non‐invasive endothelium flow mediated vasodilatation (FMD). Methods We studied 20 POAG patients. The diagnostic criteria for POAG was an IOP exceeded 22 mm/hg before treatment, open anterior chamber angle, cup/disc ratio >0.7 and optic nerve related visual field loss (MD>6 dB, SF>2.5 dB and CPSD>3 dB). Patients with systemic diseases such hypertension, heart failure and diabetes mellitus were excluded. All patients and 20 normal controls underwent measurement of FMD with high‐resolution 2‐dimensional ultrasonographic imaging of the brachial artery by a Philips ENVISOR echographic machine. To induce iperemia a sphygmomanometer cuff was inflated to 250 mm/hg for 5 minutes. The cuff then was deflated rapidly and at 60 seconds after cuff deflation 2‐D images of the brachial artery were recorded for 5 seconds. A statistical analysis was made of the FMD in POAG and in normal control patients using the Student “t” test for unpaired data and the Pearson correlation test to show the correlation between the endothelial dysfunction and the visual field indexes. Results Patients affected by POAG exhibit lower values of FMD compared with healthy people In POAG patients we found an FMD 4,28%±2,49 vs. 8,66%±3,02 (p<0.001). The mean decrease (MD) visual field index was related to FMD (p<0.05). Conclusion Patients with POAG have an impaired vascular function related to a vascular endothelium dysfunction and the MD visual field is related to FMD impairment.
Measurement of IOP with radiowave telemetry
Authors: TODANI A , FAVA M , BEHLAU I , MELKI S , DOHLMAN CH 
Published: September 2009

Abstract Purpose To illustrate the implantation technique & tolerance of a novel wireless silicone‐encased intraocular pressure transducer in rabbit eyes. The device can conceivably provide a reliable way to measure the IOP in situations where measurement is difficult with the present technology, for instance in eyes with keratoprosthesis implants. Methods The transducer, manufactured by Mesotec GmbH (Hannover, Germany), is a fully digital ultra miniature system, integrating pressure sensing, data handling and telemetry on a single microchip. The microchip is connected to a telemetry coil and requires no internal power source. The data is received using an external reader unit. The transducers were initially tested for calibration in enucleated bovine eyes. They were sterilized with ethylene oxide. They were implanted either through a corneal autograft (n=2) or through a large limbal incision (n=2) and placed either in the sulcus (n=2) or suspended into the vitreous cavity (n=2) after removing the crystalline lens. In one rabbit (SHAM), the crystalline lens was removed but no implant was placed. The eyes were closed with interrupted 10‐0 nylon sutures. Daily observations and weekly full clinical examinations were performed. The readings obtained by the transducer‐readers were compared with those obtained by Tonopen. Results The transducers were well tolerated, with minimal transient post‐operative intraocular inflammation that was similar in both the experimental and SHAM groups at comparable time‐points. The pressure obtained by the transducers showed good correlation with those obtained by Tonopen. Conclusion Our animal studies show that the transducer can be easily implanted and is well tolerated inside the rabbit eye, up to 4 months at the present time.
Retinal oxygenation in diabetic retinopathy
Authors: HARDARSON SH , OLAFSDOTTIR OB , KARLSSON RA , BEACH JM , EYSTEINSSON T , BENEDIKTSSON JA , STEFANSSON E 
Published: September 2009

Abstract Purpose Diabetic retinopathy (DR) is believed to cause retinal tissue hypoxia by damaging retinal capillaries. The purpose of this study was to examine the effect of diabetic retinopathy on oxygen saturation in retinal arterioles and venules. Methods The retinal oximeter (Oxymap ehf., Reykjavik, Iceland) is composed of a fundus camera, beam splitter and light filters. Specialized software calculates relative oxygen saturation from light absorption at two wavelengths of light (605nm and 586nm). One first or second degree temporal arteriole and venule were measured in one eye of 31 healthy individual and 28 patients with diabetic retinopathy. The diabetic patients had background DR (n=6), macular oedema (n=7), untreated preproliferative or proliferative DR (n=7) or stable proliferative DR after treatment (n=8). Statistical analyses were performed with an unpaired t‐test, one‐way ANOVA and Dunnett's post test. Results Retinal arteriolar saturation was 93±4% (n=31, mean±SD) in healthy subjects and 101±6% (n=28) in patients with DR (p<0.0001). Retinal venular saturation was 58±6% in healthy subjects and 67±8% in diabetic patients (p<0.0001). Arteriolar and venular saturation was higher in all subgroups of diabetic patients (see methods) than in healthy subjects. Conclusion Increased oxygen saturation in retinal vessels in diabetic retinopathy, also found by other researchers, is consistent with poor distribution of blood and oxygen to the retinal tissue rather than decreased total retinal blood flow. Poor distribution of oxygen may be caused by capillary dropouts and shunts as well as thickening of the capillary walls.
Commercial interest
Retinal vessel oximetry made simple and reliable ‐ principle, performance and clinical results
Authors: HAMMER M , SCHWEITZER D 
Published: September 2009

Abstract Purpose The regulation of the oxygen supply to the retinal tissue is critical and the detection of alterations in the oxygen supply or consumption may have a diagnostic merit. Quantitative assessment of oxygen supply and oxygen utilization in the tissue requires the measurement of the blood flow as well as the blood oxygenation. While the blood flow can be calculated from laser Doppler velocimetry and the vessel diameter, the intra‐vascular heamoglobin oxygen saturation (SO2) can be determined by a photometric measurement. Methods In the current approach, the SO2 is measured by a dual – wavelength technique. Using a fundus camera, equipped with a special dual wavelength transmission filter and a color CCD camera, two monochromatic fundus images at 548 nm and 610 nm were recorded simultaneously. The optical densities of retinal vessels for both wavelengths and their ratio, which is known to be proportional to the oxygen saturation, were calculated. Measurements of SO2 were performed in patients with diabetic retinopathy, arterial occlusion, and healthy controls. Furthermore, the changes of SO2 upon flicker light stimulation of the eye were investigated. Results From a healthy control population, mean arterial and venous SO2 were measured to be 98±10.1% and 65±11.7% with reproducibility of 2.52% and 3.25% respectively. In 10 patients with central or branch vein occlusion, a reduction of the arterial SO2 to 62±11% was found in the occluded vessel. After 5 days on pentoxifilin therapy, the SO2 increased to 90±16%. Diabetics showed venous SO2 increasing with the severity of the retinopathy. Flicker increased the venous SO2 by about 5%. Conclusion Dual wavelength oximetry is a simple and reliable method for physiological and clinical investigations.
Commercial interest
Screening history of those with severe visual impairment due to diabetic retinopathy
Authors: HART PM , HART PW , JACKSON AJ 
Published: September 2009

Abstract Purpose To examine screening activity prior to blind registration due to diabetic retinopathy (DR) in NI. To identify any grading misclassifications and risk factors for blindness in those screened. Methods Details on all registered blind due to diabetic retinopathy were obtained from the statutory register (SOSCARE). Demographic data (surname, date of birth and sex) were used in any combination to ascertain previous screening within the evolving NI Diabetic Retinopathy Screening Programme. Screening history and clinical chart review formulated the history prior to registration. Results The prevalence of diabetic blindness amongst the diabetic population was 0.34%.(171 people) 56% were female and the average age was 65.6(SD 15.6). Diabetic maculopathy was cited as the commonest cause ( 83%) with proliferative disease in 17%. 84% had never been screened and were under the care of an eye clinic. 27 people ( 16%) had been screened within the previous 4 years. 22 of these had been discharged from eye clinics post registration. 5 had never attended an eye clinic. 4 of these showed maculopathy on screening and were referred to an ophthalmologist. One person aged 31, diabetic for 20 years, was screened 2 years prior to registration due to PDR. The screening result was given as no retinopathy in either eye. The digital images were reassessed and no change in grade made. Detailed scrutiny of clinical notes revealed a recent history of severe anorexia with insulin used to control weight. Conclusion Timely referral from screening is required for optimal management, but it must be recognised that vision cannot be maintained in all cases. Risk factor stratification for earlier screening in exceptional circumstances may be wise.
Commercial interest
Needs from residents’ perspective and SOE YO
Authors: KHAWAJA A 
Published: September 2009

AbstractA resident's training needs are very diverse and include acquiring knowledge to pass exams, clinical skills, surgical skills and business acumen. Modern training programs aim to deliver each of these requirements in a more structured and reproducible format. However, not all these needs are amenable to structure. These challenges will be discussed and the recently introduced training scheme in the UK will be highlighted as an example.
Professionalism and appraisal
Authors: DUA HS 
Published: September 2009

AbstractProfessionalism is defined as the expertness characteristic of a professional person. A true professional encompasses attributes of integrity, honesty, transparency, fairness, trust, respect, dignity, courtesy and ethical behaviour, working within means with insight into limitations, updating knowledge & skills, communicating effectively and others. Professionalism also involves striking a balance between conflicting pressures such as work and life, family and colleagues and saying “yes” and “no”. In short, professionalism is the ability to put all the above together. Appraisal is a two way process in which the appraiser and appraise together, in a non‐confrontational manner identify the needs of the appraise, establish the means of fulfilling those needs and set objectives and timeframes in which to achieve those needs. Achievements are recognised and appreciated, problems and their causes where possible are identified and means of solving them are considered and action points agreed. Appraisal should occur regularly. All necessary information should be gathered beforehand, discussed during the appraisal and goals set for the next appraisal. The next cycle should begin by considering the goals set previously and understanding why some were not met and acknowledging those that were. The whole process should be a positive and constructive experience for the appraise. The individual should have confidence in the appraisal process and look upon it as a process whereby his accomplishments are recognised and where he or she can openly discuss concerns and find answers. A good appraisal benefits the individual and the employing organisation. Unlike ‘assessment’ it does not pass judgement on the individual’s performance but represents a concerted effort to improve performance.
Commercial interest
Symmetry of retinopathy in the NI diabetic retinopathy screening programme NIDRSP
Authors: HART PM , STEVENSON MR 
Published: September 2009

Abstract Purpose To predict the probable level of retinopathy in an ungradeable image from the retinopathy status in the gradeable fellow eye Methods Retinopathy is graded within NIDRSP on a well established grading scale ( 0‐6) based on the ETDRS scale. The retinopathy status ( screening grades) was taken from a cohort of 5000 consecutive patients. Inter eye correlations in grading outcome were examined Results A high degree of symmetry in retinopathy grades was found. At the lower levels of grade the right eye tended to be slightly worse than the left If a retinopathy grade of 0( none ) to 2 ( definite early retinopathy) was found in the right eye If no retinopathy was found in 1 eye ( right or left), the probability of having referable retinopathy in the fellow eye was found to be zero. If moderate non referable retinopathy was found in the right eye, the probability of having referable retinopathy in the left was 8%. If moderate non referable retinopathy was found in the left eye , the probability of having referable retinopathy in the right was 6%. If referable retinopathy was found in the right eye, referable retinopathy was present in the left in 60%. If referable retinopathy was found in the left eye, referable retinopathy was found in the right eye in 46%. Conclusion At more advanced levels of retinopathy the probability of having sight threatening retinopathy is higher for the left eye than for the right. This should be considered when referring patients in whom the retinal status of one eye is masked by eg media opacities.
Commercial interest
Central corneal thickness and its association with ocular and general parameters in indians. Central India Eye and Medical Study
Authors: JONAS JB , NANGIA V , SINHA A , MATIN A , KULKARNI M 
Published: September 2009

Abstract Purpose To evaluate the distribution of central corneal thickness and its associations in the adult Indian population Methods The Central India Eye and Medical Study is a population‐based study performed in a rural region close to Nagpur in Central India and included 4711 subjects (aged 30+ years) out of 5885 eligible subjects. This study was focused on central corneal thickness (CCT) as measured by sonography and it associations. Intraocular pressure was measured by applanation tonometry. Results CCT measurement data were available for 9370 (99.4%) eyes. Mean CCT was 514±33 mm (median:517 mm; range: 290‐696 mm). In multiple regression analysis, CCT was significantly associated with male gender (P<0.001), higher body mass index (P=0.028), lower age (P<0.001), lower corneal refractive power (P<0.001), and higher anterior chamber depth (P=0.025). CCT was not significantly associated with axial length (P=0.39), lens thickness (P=0.65), refractive error (P=0.12) and cylindrical refractive error (P=0.75). Intraocular pressure readings increased significantly (P<0.001) with higher CCT and higher corneal refractive power Conclusion Indians from rural Central India have markedly thinner corneas than Caucasians or Chinese. As in other populations, CCT is higher in males. It decreased with higher age and lower body mass index. Intraocular pressure readings were falsely high in eyes with thick corneas and steep corneas. Besides corneal thickness, the anterior corneal curvature has to be taken into account in applanation tonometry. It may hold true particularly after corneal refractive surgery.
N‐Acetyl cysteine (NAC) attenuates neuronal cell death in culture not solely by up regulating glutathione (GSH).
Authors: ABDUL MAJID AS , OSBORNE NN 
Published: September 2009

Abstract Purpose To show that NAC attenuates GB (glutamate/buthionine sulfoximine)‐induced death to retinal ganglion cells (RGC‐5 cells) in culture by a mechanism that does not solely involve GSH. Methods Transformed retinal ganglion (RGC‐5) cells grown in culture were exposed to an insult of GB for defined periods. NAC at different concentrations or vehicle was added to the cultures over 24 hours. Reactive oxygen species (ROS) generation was measured using a dye 20,70‐dihydroethidium. Cell death was measured by use of an MTT and resazurin‐assays and evidence for apoptosis was obtained with an APOPercentage™ procedure. Glutathione (GSH), catalase (CAT), gluthathione‐S‐transferase (GST) and superoxide dismutase (SOD) were also determined using a different fluorescent procedure. Results NAC dose‐dependently attenuated GB‐induced generation of ROS and death by a form of apoptosis to RGC‐5 cells in culture. NAC also independently stimulated the production of not only GSH but also GST, CAT and SOD. Moreover, NAC attenuated GB‐induced loss of intracellular GSH, CAT and GST. Conclusion NAC significantly blunts oxidative‐induced death to RGC‐5 cells induced by GB. Evidence is also provided to show that NAC increases intracellular GSH, GST, CAT and SOD levels. The neuroprotective action of NAC is therefore complex and is not solely caused by an action on GSH.