bluuebunny/crossref_metadata_2025_split huggingface dataset:
A rat model to study choroidal blood flow
Authors: STROHMAIER C , RUNGE CW , BOGNER B , GRABNER G , REITSAMER HA 
Published: September 2009

Abstract Purpose To develop a model for the investigation of blood flow of in the choroid of rats. Due to their similarities in ocular blood supply und availability, rats are becoming increasingly interesting models in ocular blood flow research. The ability of choroidal autoregulation during changes in perfusion pressure has been shown in various species already. The presented study aims to show autoregulation in the choroid in a new model for blood flow measurement in the choroid of rats. Methods Male Brown‐Norway rats were anesthetised with Ketamin Hydrochloride (100 mg/kg) i.p.. A catheder for blood pressure measurement was inserted into the right femoral artery and advanced to the aorta, another catheter was inserted into the right femoral vein for drug administration. Pentobarbital was used to provide adequate anaesthesia for the following procedures, subsequently the animal was respired via a tracheotomy. Endtidal CO2 was kept in the range between 35 – 45 mmHg and airway pressure was limited to 6 cm H2O. A thoracotomy was performed through the 8th intercostal space and a hydraulic occluder was placed around the inferior vena cava just above its passage through the diaphragm. Choroidal blood flow was measured with a custom‐made, non‐invasive laser Doppler Flowmeter. Results Blood pressure was reduced through a mechanical reduction of venous return, typically from 80 mmHg to 20 mmHg. Between 80 and 50 mmHg, blood flow remained virtually constant, between 50 mmHg and 20 mmHg, a linear relationship between blood pressure and blood flow was observed. Conclusion The presented model is appropriate for the investigation of blood flow in the choroid of rats. Autoregulation in the choroid of rats could be demonstrated.
Differential effects of ageing on foveal and peripheral colour vision
Authors: RAUSCHER F , EDGAR D , BARBUR J 
Published: September 2009

Abstract Purpose Colour sensitivity was assessed to establish aging effects both at the fovea and 6 deg away from fixation, in each of the four quadrants. Methods 65 normal healthy subjects (from 20 to 80 years of age) took part in the study. All subjects had Visual Acuity (VA) of 6/6 or better. Fixation accuracy was monitored using infrared imaging of the pupil and the tests were carried out on the P_SCAN system. Target size was adjusted for parafoveal locations to account for retinal and cortical magnification. Yellow‐blue (YB) and red‐green (RG) colour discrimination was assessed using the CAD (colour assessment and diagnosis) test (http://www.caa.co.uk/docs/33/200904.pdf). Results RG and YB colour thresholds were analysed separately for all five locations tested and showed no significant effect with ageing below the age of 60 years. Two age bands were formed based on statistical analysis (20‐59.9 and 60‐79.9). The decline in performance with age was more rapid at the fovea and exhibited a steeper gradient when compared with results in the periphery for both RG and YB discrimination. Foveal YB discrimination showed the largest ageing effect. No significant difference was found between the four parafoveal locations. YB discrimination at the fovea also exhibited the largest inter‐subject variability. Conclusion These findings may have clinical significance in the very early detection of disease processes that remain subclinical in many subjects. Differences between foveal and peripheral locations help to differentiate between the normal effects of ageing and disease. For example, higher foveal and normal peripheral YB thresholds in normal subjects from high peripheral thresholds in early glaucomatous subjects.
On the effectiveness of cone mosaic geometry in sampling patterns near the Nyquist frequency
Authors: GINIS H , PERDIKARIS K , PALLIKARIS A 
Published: September 2009

Abstract Purpose The cone mosaic is characterised by a quasi‐periodic hexagonal organization. The purpose of this work was to develop a mathematical model of cone mosaic including irregularities and to employ this model to evaluate its effectiveness in sampling simple patterns including optotypes (letters) of different sizes and gratings. Methods Cone mosaic images were analyzed using purposely‐developed computer programs and a stochastic model of the human cone mosaic was created. The computer‐generated mosaics were used to sample sequences of patterns translated to positions randomly extracted from experimental data of fixational eye movements. The sampling efficiency was evaluated as the RMS difference between the initial and the sampled pattern. Similar simulations were performed using a periodic mosaic of equal average cone size. Results Sampling efficiency (as described by the minimum RMS difference) was better for the quasi‐perioding sampling compared to the periodic sampling especially when the sampled pattern involved spatial frequencies higher than 20 cpd. The periodic sampling performed better only in the case where the spatial frequencies in the Fourier spectrum of the sampled pattern exactly matched the spatial frequency associated to the cone spacing (divided by an integer). However the quasi‐periodic sampling was more effective in all other pattern sizes and orientations. Conclusion Although the trichromatic nature of the human cone mosaic as well as the neural organization in the retina after phototransduction were not taken into account, our simulations demonstrate that the geometric irregularities at the cone mosaic may result to more efficient sampling of simple patterns of arbitrary size and orientation.
Distribution of amyloid and BIG‐H3 in the cornea and limbus of a patient with lattice corneal dystrophy. Unique findings in donated eyes
Authors: AKHTAR S , ALMUBRAD T , BRON AJ , BONSHEK R 
Published: September 2009

Abstract Purpose The lattice corneal dystrophies (LCDs) are hereditary diseases involving the formation of opaque or refractile, amyloid‐containing filaments in the corneal stroma. We report the distribution of amyloid and big‐h3 protein in cornea and limbus in a patient suffering with LCD. Methods An 84 year‐old patient with lattice corneal dystrophy died and donated her eyes for further study. The corneal and limbal tissue of the patient processed for light and electron microscopy. The primary polyclonal antibody big‐h3 was located by secondary, goat anti‐rabbit antibody conjugated with gold. Results In cornea amyloid deposits were observed below epithelium, and in the anterior and middle stroma. The epithelium was thin and invaginated by the amyloid deposits. In the limbus, large numbers of amyloid deposits were observed in sub‐epithelial region, and in the mid and deep stroma. Subepithelial amyloid was also present in the substantia propria beneath the bulbar conjunctival epithelium. The amyloid deposits contained very thin amyloid fibrils and strongly stained with big‐h3 antibody. There were also numerous long spacing collagen fibrils observed in the mid stroma, which also labelled with the antibody. Conclusion This is the first report of structural changes in the peripheral cornea and limbus in LCD. It is thought that mutated big‐h3 protein diffuse into the stroma from the corneal epithelium to form amyloid deposits. The presence of amyloid and big‐h3 at the limbus and in the adjacent bulbar conjunctiva and perilimbal cornea, suggests that Big‐h3 is overproduced in these regions, which are normally free from clinically detectable disease.
Sutureless and glue free conjunctival autograft in pterygium surgery
Authors: DE WIT DW , MOORE J 
Published: September 2009

Abstract Purpose To review the safety and efficacy of sutureless and glue free conjunctival autografting for the treatment of primary pterygium Methods Retrospective case notes review of 8 consecutive patients undergoing primary pterygium excision performed by a single surgeon over a 1 year period. Excision of the pterygium was followed by reconstruction using suture and glue free conjunctival autograft. Results Mean follow up was 14 months (range 12 to 24). There were no transplant dislocations, failures or recurrences (0 of 8 eyes) after one year. The average operating time was 14+/‐2(SD) minutes. One patient had transient graft oedema. Visual acuity was unaltered in seven patients, one patient with significant pterygium‐induced astigmatism gained 3 Snellen lines. No major complications occurred and all patients approved of their cosmesis at their final visit. Conclusion Sutureless and glue free autologous conjunctival grafting for primary pterygium surgery appears safe and efficacious and may aid in preventing complications attributed to the use of foreign materials.
Effect of phacoemulsification on the primary open angle glaucoma control after trabeculectomy: a case‐control study
Authors: AZIZ S , SPIRES N , JAY J 
Published: September 2009

Abstract Purpose In this retrospective and comparative study, we analyzed the influence of phacoemulsification (PE) on the glaucoma control in case patients (trabeculectomy‐phacoemulsification [CE]) compared with the control that underwent trabeculectomy (T) alone in eyes with primary open angle glaucoma (POAG). Methods Twenty one patients who underwent PE subsequent to T were identified, and 41 who underwent T alone were matched. Visual acuity (VA), intraocular pressure (IOP), bleb appearance, vertical cup disc ratio (VCDR), visual field (VF), glaucoma medications, iris manipulation and complications were documented. Mean follow up was 12 months. Success was defined when IOP ≤ 21 mmHg with the abscense of glaucoma medication and/or further surgical intervention. Results Patients in CE group had no significant change in IOP from pre‐operative measures to 12 months post‐operative (p=0.001). The mean IOP reduced from 15.3 mm Hg to 14.7 mmHg postoperatively. The control group showed an average IOP reduction of 6 mm Hg in the last visit. In CE group, 19% required 1 or 2 glaucoma medications at one year fellow‐up vs 19.5% in the control group. In CE group 9.5% showed flattening of previously formed bleb in the last visit (P<0.001), 9.7 % ended with flat bleb in the T group. The increase in VCDR for the CE group was statistically significant when compared to the control group (p<0.001). Patients in CE group were more likely to exhibit a change in VF (47.6% versus 7.3% respectively). The study is limited by the small number of cases available. Conclusion Corneal PE in eyes with filtering blebs does not adversely affect long‐term glaucoma control in patients with POAG.
Inflammation assessment after selective laser trabeculoplasty (SLT) treatment
Authors: AYALA M , LANDAU HöGBECK I , CHEN E 
Published: September 2009

Abstract Purpose Glaucoma is a progressive neuropathy, reducing intraocular pressure (IOP) seems to be the only treatment to stop progression in glaucoma. There are several methods to reduce IOP: medical treatment, laser and surgery. Selective Laser Trabeculoplasty (SLT) is a new treatment alternative. SLT selectively targets the pigmented cells of the trabecular meshwork without causing thermal or collateral damage to the surroundings structures. The aim of the present study was to assess inflammation after SLT treatment. Methods 40 patients (80 eyes) were included in the study. Inclusion criteria: Glaucoma (POAG, pigmentary and pseudoexfoliative glaucoma)/ OHT patients that will be treated with SLT in just one eye, both with and without eye‐drops. Exclusion criteria: patients suffering from ocular or systemic inflammatory diseases or treated with cortisone or immunosuppressive drugs. Inflammation was measured in 2 different ways: 1) clinically with a slit lamp and classified 0‐4; 2) with a “Laser flare meter (Kowa FM 500)”. Measurements were done before, 2 hours after, 1 week and 1 month after SLT treatement, both eyes were evaluated. IOP was also checked in the same way. SLT treatment was performed in 90° with the SLT Solo Ellex laser. Results inflammation before and after SLT showed no significant difference measured both clinically with slit lamp and objectively with the laser flare meter. No inflammation was found in the untreated eyes. No IOP peaks after SLT treatment were found. Conclusion SLT treatment seems not to induce inflammation in the anterior chamber when 90° were treated. SLT treatment might be considered as a first choice treatment against high intraocular pressure.
Oculopalatal tremor
Authors: BORRUAT FX 
Published: September 2009

AbstractOculopalatal tremor is a rare but disturbing acquired motor disorder. It is a delayed complication of a brainstem lesion (usually infarction or hemorrhage) interrupting the so‐called "Mollaret's triangle" (dentato‐olivary pathway). Clinically, patients complain of vertical oscillopsia due to a rhythmical vertical pendular movement of the eyes. Other muscles can be involved, namely soft palate, pharynx, larynx, head, face, diaphragm. Hypertrophy of the inferior olivary nucleus is the hallmark of oculopalatal tremor, by MRI or by pathology. This presentation will review the current knowledge regarding the anatomic bases of this syndrome, as well as its clinical presentations, MRI findings, treatment options and pathophysiologic hypotheses.
Transthyretin levels in the vitreous correlate with change in visual acuity after vitrectomy
Authors: VAN AKEN E , VECKENEER M , DERYCKE L , DELANGHE J 
Published: September 2009

Abstract Purpose Little is known about biochemical markers related to change in visual acuity after vitrectomy. We investigated the potential use of transthyretin (TTR), a carrier of the retinol/retinol‐binding protein, as a biochemical marker protein. Methods We measured TTR using immunonephelometry in a group of patients (n=77) in longstanding (> 1 week) retinal detachment (n=29), fresh (< 1 week) retinal detachment (n=17), macular holes (n=20), or diabetic retinopathy (n=11). Vitreous samples were taken at the start of every vitrectomy procedure. For reference values, cadaver specimens (n=73) were used. Results Reference values for vitreous TTR (median 18 mg/l; IQR 4‐24 mg/l) comprised 2.2% of reference values for vitreous protein levels (median 538 mg/l; IQR 269‐987 mg/l). Vitreous TTR values of patients were comparable in all disorders. Vitreous TTR values were higher in phakic (median 22.5 mg/l; IQR 10‐27 mg/l) than in pseudophakic patients (median 12 mg/l; IQR 8‐19 mg/l)(p=0.06). Postoperative change in visual acuity correlated well with vitreous TTR values found peroperatively (rs=0.408; p=0.012). Both change in visual acuity and lens status were the only variables which proved to explain the variance of TTR (multiple correlation coefficient: 0.494; phakic status: t=2.767; p=0.0084; and change in visual acuity t=2.924: p=0.0056). Conclusion Vitreous fluid concentrations of TTR can be regarded as a biochemical marker for retinal function.
The different domains of the point spread function ‐ Small angle vs large angle
Authors: VAN DEN BERG TJTP , COPPENS JE , FRANSSEN L 
Published: September 2009

Abstract Purpose The Point‐Spread‐Function peaks at 107, and drops off to 10‐2 at 90 degrees, a dynamic range of 109. Important changes in the PSF already occur within the first 1 minute of arc, so spatially the dynamic range is 105. Very different experimental techniques are needed to describe the small angle (aberrometry, double pass) and the large angle (straylight) domains. What optical irregularities achieve such PSF? Methods Literature models for the aberration structure of the human eye media, in particular Thibos et al. JOSA A 2002 were used to derive the PSF. The Thibos et al. model was extrapolated to allow inclusion of the high orders of aberration not normally included in aberrometry, but potentially visible with double pass, so as to encompass as much as possible from the PSF. Results The modeled aberration structures of the eye covers the central part of the PSF up till about 0.3 degrees if extreme high orders were included. For angles >1 degree predicted values were far below the actual values of the PSF. On the other hand, double pass techniques grossly overestimate PSF values at angles of 0.3 degree and above. Using an alternative model for the aberration structure of the eye the PSF could be described up till 1 degree. Small particle scattering was essential to predict the PSF for angles above 1 degree. Conclusion In the assessment of disturbances to the optical media two domains must be discriminated: the aberration domain and the small particle domain, with corresponding parts (small angle vs large angle) to the PSF. Straylight originates from irregularities of small characteristic size (10 micrometer and below), as opposed to disturbances to the central part of the psf (<0.3 degrees), originating from large scale irregularities.
Commercial interest
Challenges in optical measurement of scatter
Authors: GINIS H 
Published: September 2009

Abstract Purpose Measurement of scattered light in biological media and particularly the optical media of the human eye is associated with two main challenges: The extremely low intensity of the scattered light and artefacts associated to tissue handling and preparation. Methods Our strategies in reducing the errors associated with the above mentioned challenges include the utilisation of properly designed illumination schemes and appropriate procedures and devices for excising and mounting the specimens. Results Appropriate techniques that incorporate precise knowledge of the optical PSF of the system may prove useful for the accurate measurement of scatter light. Diffraction through the utilisation of narrow (e.g. 0.5mm) diaphragms may prove useful for the broadening of the optical PSF (while preserving knowledge of its shape) and therefore allow optical measurements of a wider range of angles. Conclusion Optical measurements of scatter may prove useful not only for the macroscopic characterisation of the optical quality of the optical media of the eye but also for the extraction of information concerning the microscopic structure of the irregularities causing the loss of transparency.
Corneal biomechanics study : relationship between corneal aberration – hysteresis
Authors: PEREZ GARCIA D , IBANEZ J , VALYI Z , CASAS P , CRISTOBAL JA 
Published: September 2009

Abstract Purpose To determinate the relatioship between corneal aberration and a biomechanical parameter: the corneal hysteresis. Methods 122 eyes of 61 patients were included in a prospective and transversal study. Range of age was between 18 and 60 years. The following measurements were realised: Corneal topography with KERATRON (Optikon) to obtain the root mean square (RMS) of corneal aberration and measurement with Ocular Response Analyzer (ORA) (Reichert) to obtain the Corneal Hysteresis (CH). The correlation between RMS – CH was calculated by SPSS 12.0 (Statistical Package for the Social Sciences, Chicago, IL) using the correlation of Pearson for quantitative and independent variables. Results No statistically significant correlation could be demonstrated between RMS and CH analysing both eyes as well as left and right eyes separately. Conclusion The relationship between CH and each Zernike coefficient separately could be analysed as other studies found a correlation between intraocular pressure and high order aberrations. The importance of corneal biomechanical parameters like CH and CRF, values determined by the ORA, is not well defined yet; however the influence of these factors not only on intraocular pressure but also on corneal pathologies should be considered.
Corneal biomechanics study (1): Central corneal thickness versus corneal resistance factor
Authors: VALYI Z , IBANEZ J , PEREZ GARCíA D , JIMENEZ DEL RIO B , CRISTOBAL JA 
Published: September 2009

Abstract Purpose Study about the biomechanical characteristics of the cornea. Methods We studied 122 eyes of 61 patients (33 women and 28 men) selected prospectively and consecutively. Range of age was between 18 and 60 years. The following determinations were carried out: Corneal topography with KERATRON (Optikon), measurement with ORA (Reichert) and ultrasonic pachymetry. The correlation between CCT ‐ CRF was calculated by SPSS 12.0 (Statistical Package for the Social Sciences, Chicago, IL) using the correlation of Pearson for quantitative and independent variables. Results We found after statistical analysis of data, a statistically significant correlation between the corneal resistance factor determined by the ORA, and central corneal thickness measured by ultrasonic pachymetry. The results are similar analysing both eyes as well as left and right eyes separately. Conclusion The importance of corneal biomechanical parameters like CH and CRF, values determined by the ORA, is not well defined yet; however the influence of these factors not only on intraocular pressure but also on corneal pathologies should be considered.
Heterogeneity in uveal melanoma assessed by multiplex ligation‐dependent probe amplification (MLPA)
Authors: DOPIERALA J , COUPLAND SE , DAMATO B 
Published: September 2009

Abstract Purpose To study intratumour heterogeneity in primary uveal melanoma (UM) by MLPA in microdissected formalin‐fixed, paraffin‐embedded (FFPE) tissues. Methods DNA was extracted from 2‐9 areas microdissected from 32 FFPE UMs. Thirty‐one loci on chromosomes 1p, 3, 6 and 8 were tested for copy number changes using the SALSA MLPA P027.B1 assay (MRC Holland). MLPA data were displayed as dosage quotients (DQs), which were classified to 5 ranges (0.35‐0.64 deleted; 0.65‐0.84 equivocal deletion; 0.85‐1.14 normal; 1.15‐1.35 equivocal amplification; >1.35 amplified). The tumour was considered heterogeneous at a locus, if a) the difference in DQs of any two areas was higher than 0.2 (value determined by ROC analysis), and b) the DQs of the areas belonged to different ranges. Results Genetic abnormalities were detected in all 32 UMs. Monosomy 3, the most significant metastasis predictor, and gain of 8q genes MYC or DDEF1 were detected in at least 1 microdissected area of 22 (69%) and 28 (87%) of the tumours, respectively. The comparison of MLPA data obtained from different areas of UMs showed heterogeneity in 1‐24 loci across chromosomes 1p, 3, 6 and 8 in 26 (81%) tumours. Interestingly, trisomy 3 was observed in 3 (9%) UMs and these tumours showed the highest degree of heterogeneity (>23 heterogeneous loci). Intratumour heterogeneity of 3p12.2 (ROBO1) and 6p21.2 (CDKN1A) were most common and present in more than 35% of the tumours. Conclusion Heterogeneity of chromosomal abnormalities of 1p, 3, 6 and 8 is present in many UM. Taking one random tumour sample for prognostic testing, therefore, may not be representative of the whole tumour.