bluuebunny/crossref_metadata_2025_split huggingface dataset:
Refractive status and the 5‐year incidence of age‐related maculopathy: the Blue Mountains Eye Study
Authors: Wang Jie Jin , Jakobsen Kirsten B , Smith Wayne , Mitchell Paul 
Published: June 2004

AbstractThis study aimed to assess the longitudinal association between refraction and 5‐year incident age‐related maculopathy (ARM) in the Blue Mountains Eye Study population. The dataset included 3654 participants aged 49+ (82.4% of eligible) examined at baseline (1992−1994), and 2335 (75.1% of survivors) examined after 5 years. Retinal photograph grading followed the International ARM Classification. Incident ARM was assessed using a side‐by‐side comparison. Refraction was performed using autorefraction with subjective refinement. Spherical equivalent was calculated from spherical plus half the cylindrical power. After adjusting for age, sex and smoking, no association was found between baseline spherical equivalent and 5‐year incident late or early ARM. Hyperopic right eyes had slightly higher incident rates for late (0.8%) and early (6.3%) ARM, compared with myopic (0.4% and 4.1%, respectively) or emmetropic (0.5% and 5.0%, respectively) right eyes. After multivariable adjustment, this study found no significant association between hyperopia and the 5‐year incidence of late or early ARM. Left eyes or the combined data from both eyes had similar findings.
Menstrual cycle dependent changes in blue‐on‐yellow visual field analysis of young diabetic women with severe non‐proliferative diabetic retinopathy
Authors: Apaydin K Cemil , Akar Yusuf , Akar Munire Erman , Zorlu Gurkan C , Ozer Hilmi O 
Published: June 2004

Abstract Purpose: To evaluate menstrual cycle dependent changes on blue‐on‐yellow visual fields of diabetic women, and to compare the results with those of healthy women. Methods: Left eyes of 93 normally menstruating women were included in the study, comprising 45 with type‐1 diabetes mellitus and severe non‐proliferative diabetic retinopathy and 48 healthy controls. All subjects underwent baseline complete ocular examination and achromatic visual field analysis. Blue‐on‐yellow visual field tests (short‐wavelength automated perimetry) were performed in both follicular (days 7−10 of the cycle) and luteal phases (days 3−6 before the bleeding) of two consecutive menstrual cycles. Visual field analyses were performed using Humphrey Field Analyser II with full threshold, central 30−2 program. Visual fields were divided into four regions: superior temporal, inferior temporal, superior nasal and inferior nasal. Visual field mean sensitivity (MS) was calculated for all regions separately. Results: The mean ages of diabetic and control subjects were not significantly different (P > 0.05). Mean MS values of the diabetic group were significantly lower than that of the control group (P < 0.05). Control subjects did not demonstrate any menstrual cycle dependent changes in MS values (P > 0.05). However, diabetic women demonstrated a significant decrease in MS values in the luteal phase (P < 0.05). The decrease in MS was most marked in the nasal visual field (P < 0.05). Conclusion: Young diabetic women demonstrated a significant depression in visual field threshold sensitivity in the luteal phase of the menstrual cycle. Nasal visual fields are more prone to have menstrual cycle dependent threshold sensitivity depression. This should be taken into consideration in the clinical assessment of women with advanced diabetes who are at risk of glaucomatous optic neuropathy.
Effect of check size and stimulation rate on blue−yellow multifocal visual evoked potentials
Authors: Martins Alessandra , Klistorner Alexander , Graham Stuart , Billson Frank 
Published: June 2004

Abstract Background: To determine the effect of different stimulus frame rates and check sizes on blue−yellow multifocal visual evoked potentials (mVEP). Methods: Subjects were examined at the Save Sight Institute at the University Sydney. Experiment 1 involved five adult subjects who underwent binocular stimulation by the Accumap multifocal objective perimeter. The eyes were stimulated with a cortically scaled dartboard pattern consisting of isoluminant blue and yellow checks. These were arranged in three concentric rings extending to an eccentricity of 26° in the visual field. The stimulus pattern was driven by binary sequences resulting in pseudorandom binary exchange of two opposite checkerboard patterns at each of the 32 sites in the visual field. The mVEP were recorded at two different rates of display of the pattern stimulus. In experiment 2, mVEP were tested on 10 normal subjects. Each of the 36 stimulation sites contained a checkerboard pattern of 20, 30, 42 or 56 checks/site, the stimulation pattern was displayed at the optimum rate found in experiment 1. The size of the checks was inversely proportional to the number of checks per site. Results: In experiment 1, the slow frame rate significantly increased the average amplitude throughout the field tested by 50 ± 10.1% (P = 0.001). Latency was significantly shortened by 6.3% (P < 0.01). In experiment 2, the average amplitude peaked at 30 checks per segment; however, this was only calculated to be significantly different from the smallest check size (Fcrit range 4,27 = 0.09 P < 0.05, anova, Tukey's T method). A similar difference was found in ring 1 (Fcrit range 4,27 = 0.09, P < 0.05, anova, Tukey's T method). In ring 2, however, there was also a significant difference between 56 checks and 20, 30 and 42 (Fcrit range 4,27 = 0.09, anova, P < 0.05). Altering the check sizes did not significantly affect the amplitudes in ring 3. The latencies were not significantly modified by altering check size at any eccentricity. Conclusions: These findings suggest that slowing the stimulation rate and displaying 30 checks per stimulation segment optimizes the blue−yellow mVEP stimulus.
Increase in cataract surgery prevalence from 1992−1994 to 1997−2000: analysis of two population cross‐sections
Authors: Tan Ava Grace , Wang Jie Jin , Rochtchina Elena , Jakobsen Kirsten B , Mitchell Paul 
Published: June 2004

Abstract Background: Monitoring temporal changes in the demand for and provision of cataract surgery will be useful to health planners to meet resource needs and to estimate likely costs. The aim of this report was to compare the prevalence of cataract surgery in two population cross‐sections of the Blue Mountains Eye Study (BMES), over an interval of around 6 years. Methods: Cross‐section I (n = 3654; mean age 66.2 years) consisted of BMES I participants (1992−1994). Cross‐section II (n = 3509; mean age 66.7 years) consisted of BMES II (5‐year) participants (n = 2335) plus persons who had moved into the area and age category since BMES I (n = 1174), so were newly eligible (1997−2000). Cataract surgery history was collected during interview and confirmed at examination. Results: Over this 6‐year period, there was a 32% increase in cataract surgery prevalence from 6.0% to 7.9%, or from 6.0% to 7.7% after age standardization. The increase in eye‐specific prevalence was 43% (from 4.4% to 6.3%). It was more marked among persons aged 80+ years and for bilateral (from 12.3% to 19.9%) than unilateral surgery (from 10.7% to 11.8%). Best‐corrected visual acuity (mean letters read correctly) after surgery (43 and 44 letters, respectively) was similar between cross‐sections I and II. Conclusions: The findings from a representative older population confirm that prevalent cataract surgery has increased substantially over the average 6‐year period, from 1992−1994 to 1997−2000.
Effects of binocular form deprivation on the excitatory post‐synaptic currents mediated by N‐methyl‐D‐aspartate receptors in rat visual cortex
Authors: Qin Wei , Yin Zheng Qin , Wang Shijun , Zhao Yanjun 
Published: June 2004

Abstract Purpose: To investigate the effects of binocular form deprivation (BFD) on the excitatory post‐synaptic currents (EPSCs) mediated by the N‐methyl‐D‐aspartate (NMDA) receptor (NMDA‐EPSCs), and the proportion of NMDA‐EPSCs relative to glutamate receptor currents (glutamate‐EPSCs) in rat visual cortex. Methods: Binocular form deprivation was achieved by suturing the eyelids of Wistar rats at postnatal day (PD) 14, before eye‐opening. Visual cortical slices (300 µm) were prepared from normal and BFD Wistar rats aged PD 14, 21 and 28. Recordings were obtained in slices from layer II to IV using the whole‐cell patch‐clamp technique. Glutamate‐EPSCs were isolated in the presence of bicuculline methiodide (20 µmol/L) in the bathing medium, and NMDA‐EPSCs were isolated with a combination of bicuculline methiodide (20 µmol/L) and 6‐cyano‐7‐nitroquinoxaline‐2,3‐dione (CNQX, 20 µmol/L). In addition, D,L‐2‐amino‐5‐phosphonovalerate (AP‐5, 20 µmol/L) was applied to study the NMDA‐only mediated currents. For each cell, the ratio of peak NMDA to glutamate EPSCs was calculated. Results: During visual development, the decay time constant of NMDA‐EPSCs became shorter after eye‐opening in normal rats (F = 5.949, P <0.05; PD 28 vs PD 14, P = 0.027), but not in rats with BFD (P > 0.05). The weighted time constant of NMDA‐EPSCs in the visual cortex became shorter after the rats’ eyes were opened in the normal group (F2,37 = 4.727, P = 0.015; PD 28 vs PD 14, P = 0.035), but not in the BFD group (P > 0.05). However, the rise time constant and peak value of NMDA‐EPSCs showed no significant changes in normal and BFD groups (P > 0.05). The ratio of NMDA‐EPSCs to glutamate‐EPSCs became gradually smaller with age in the normal rats (F = 4.661, P < 0.05; PD 28 vs PD 14, P = 0.025), but not in the BFD group (P > 0.05). Conclusions: These studies reveal that the proportion of NMDA‐EPSCs relative to glutamate‐EPSCs and the decay time constant of NMDA‐EPSCs are influenced by BFD. These changes may reflect important experience‐dependent modifications of neuronal synapses in visual cortex.
Iris melanoma: pathology, prognosis and surgical intervention
Authors: Starr Oliver D , Patel Dipika V , Allen Jonathan P , McGhee Charles NJ 
Published: June 2004

AbstractA case of an iris melanoma in a 58‐year‐old woman is described. The clinical and pathological findings are discussed, highlighting the correlations between histopathology and prognosis for iris melanoma, which differ markedly from choroidal melanoma. The mixed cellular pathology of this iris melanoma (containing both spindle B cells and epithelioid cells) carries a higher metastatic rate than tumours composed exclusively of either. This contrasts with choroidal melanoma, where the presence of epithelioid cells is the strongest pathological marker for a poor prognosis. The ocular outcome that can be achieved with local surgical excision of a well‐delineated iris melanoma that does not involve the angle is discussed.
Tapioca melanoma of the iris mimicking a vascular tumour: a clinicopathological correlation
Authors: Viestenz Arne , Conway Robert M , Küchle Michael 
Published: June 2004

AbstractAlthough vascular iris processes are usually benign, they may be a clinical manifestation of iris melanoma, and this should be considered in the differential diagnosis. The case is reported of a 20‐year‐old man with a highly vascularized tapioca melanoma of the left iris without involvement of the anterior chamber angle or ciliary body, but with observed growth tendency. Sector iridectomy was performed 2 months after first examination. In addition, two separate floating tumour nodules were observed in the anterior chamber angle at 6 o’clock and were removed by aspiration. After 1 year follow up, no recurrence of melanoma cells was observed. In tapioca iris melanomas, diagnostic differentiation from congenital, inflammatory, vascular and neoplastic iris processes is required. Careful biomicroscopic examination of the iris in patients with vascular iris tumours may help the ophthalmologist to identify malignant iris melanomas (tapioca type) and plan appropriate surgical treatment.
Optic neuropathy secondary to radiotherapy for nasal melanoma
Authors: Garrott Helen , O'Day Justin 
Published: June 2004

AbstractOptic neuropathy is a rare but important complication of radiotherapy used in the treatment of cancers of the head and neck, usually resulting in rapidly progressive blindness in one or both eyes. The case is presented of a 77‐year‐old woman with bilateral optic neuropathy resulting in blindness, secondary to radiotherapy for a melanoma of the nasal cavity. The onset of optic neuropathy occurred 9 months post‐radiotherapy, at a cumulative dose of 6000 rad. The left eye was first involved, with the right eye becoming involved within 2 weeks. Despite treatment with oral anticoagulation and high dose intravenous methylprednisolone, there was progressive deterioration resulting in bilateral optic atrophy, with final visual acuities of perception of light in the right eye and no perception of light in the left eye. This case demonstrates that oral anticoagulation was ineffective in the treatment of progressive radiation‐induced optic neuropathy.
Visual loss despite anticoagulation in radiation‐induced optic neuropathy
Authors: Danesh‐Meyer Helen V , Savino Peter J , Sergott Robert C 
Published: June 2004

AbstractRadiation therapy to the brain may produce necrosis and loss of function months after completion of the treatment. The case is presented of a 62‐year‐old man who developed radiation‐induced optic neuropathy 2 years after treatment for a glioma of the left temporal lobe, despite being on anticoagulation therapy. Although anticoagulation appears to be beneficial in cerebral radiation necrosis, its usefulness in the treatment of radiation‐induced optic neuropathy is unclear.
Progressive visual loss in a patient with presumed temporal arteritis despite treatment: how to make the diagnosis
Authors: Zborowska Bogna , Ell Jonathan , McGee‐Collett Martin , Scolyer Richard , McCluskey Peter J 
Published: June 2004

AbstractGiant cell (temporal) arteritis is a severe potentially fatal systemic vasculitis characterized by focal involvement of the cranial arteries resulting in ischaemic arterial occlusion. The case is presented of a 75‐year‐old woman with presumed giant cell arteritis and normal bilateral temporal artery biopsies. Despite a seemingly adequate course of systemic steroid therapy, the patient developed sudden catastrophic vision loss. Cerebral angiography and ultrasonography were useful investigations to determine the most appropriate artery to biopsy to confirm the diagnosis of giant cell arteritis.
Pathological features of surgically excised polypoidal choroidal vasculopathy membranes
Authors: Kuroiwa Sachiko , Tateiwa Hisashi , Hisatomi Toshio , Ishibashi Tatsuro , Yoshimura Nagahisa 
Published: June 2004

AbstractThe histopathological features are reported of surgically excised specimens from five patients with polypoidal choroidal vasculopathy, which had been diagnosed by indocyanine green angiography. On stereomicroscopy, four of the five cases demonstrated large choroidal arterioles with an inner elastic layer. Disruption of the inner elastic layer and arteriosclerotic changes of the vessels were identified by light microscopy. Transmission electron microscopy demonstrated increased deposition of basement membrane‐like material, together with collagen fibres, in the arteriolar walls. This study indicates that large choroidal arterioles and venules can be found in excised specimens from patients with polypoidal choroidal vasculopathy and arteriosclerosis is an important pathological feature.
Anterior uveitis in a child with Takayasu's arteritis
Authors: McDonald Mark A , Ojaimi Elvis , Favilla Ian 
Published: June 2004

AbstractTakayasu's arteritis is a rare idiopathic arteriopathy that produces narrowing and eventually closure of affected blood vessels. Ocular symptoms typically occur late in the disease process in those individuals who have severe involvement of the aortic arch and the carotid arteries. Visual loss typically occurs as a result of either systemic hypertension or concomitant ocular hypo‐perfusion. We describe an unusual case of Takayasu's arteritis presenting in a child who complained of painful blurred vision. In this individual, no carotid artery disease was identified on vascular imaging and no evidence of impairment of ocular perfusion was demonstrable. Vision loss in this instance was due to anterior uveitis and cystoid maculopathy. These are atypical and rarely described features of Takayasu's arteritis. The patient responded well to anti‐inflammatory treatment and his symptoms resolved. The clinical significance of these findings are discussed and the relevant literature reviewed.
Isolated trochlear nerve palsy as a presenting feature of primary polycythemia rubra vera
Authors: Jones Michael M , Clement Colin I , Rowe Dominic B 
Published: June 2004

AbstractA case is reported where the onset of vertical diplopia secondary to a trochlear nerve palsy occurred as the presenting feature of polycythemia rubra vera. This may be the first report of an isolated trochlear nerve palsy secondary to polycythemia rubra vera and infarction of the fascicle or nerve.
Myopia: precedents for research in the twenty‐first century
Authors: Gilmartin Bernard 
Published: June 2004

AbstractThe myopic eye is generally considered to be a vulnerable eye and, at levels greater than 6 D, one that is especially susceptible to a range of ocular pathologies. There is concern therefore that the prevalence of myopia in young adolescent eyes has increased substantially over recent decades and is now approaching 10−25% and 60−80%, respectively, in industrialized societies of the West and East. Whereas it is clear that the major structural correlate of myopia is longitudinal elongation of the posterior vitreous chamber, other potential correlates include profiles of lenticular and corneal power, the relationship between longitudinal and transverse vitreous chamber dimensions and ocular volume. The most potent predictors for juvenile‐onset myopia continue to be a refractive error ≤+0.50 D at 5 years of age and family history. Significant and continuing progress is being made on the genetic characteristics of high myopia with at least four chromosomes currently identified. Twin studies and genetic modelling have computed a heritability index of at least 80% across the whole ametropic continuum. The high index does not, however, preclude an environmental precursor, sustained near work with high cognitive demand being the most likely. The significance of associations between accommodation, oculomotor dysfunction and human myopia is equivocal despite animal models that have demonstrated that sustained hyperopic defocus can induce vitreous chamber growth. Recent optical and pharmaceutical approaches to the reduction of myopia progression in children are likely precedents for future research, for example progressive addition spectacle lens trials and the use of the topical M1 muscarinic antagonist pirenzepine.
Optical analysis of crack tip stress fields: a comparative study
Authors: PATTERSON E. A. , OLDEN E. J. 
Published: June 2004

ABSTRACTFour optical techniques for evaluating stress intensity factors in opaque specimens are described in outline, and compared for both an artificial crack and a fatigue crack. The results are compared to a standard solution for the geometry considered. All the techniques gave acceptable results over a range of stress levels and crack lengths. The methods of caustics and strain gauges were less good, whilst photoelasticity gave consistent results over a wide range of stress levels. Comments on the ease of application and the resource implications are also made in order to assist practitioners.
Tutankhamun's chariots: secret treasures of engineering mechanics
Authors: SANDOR B. I. 
Published: June 2004

ABSTRACTThe Tutankhamun‐class chariot is the earliest high‐performance machine, most likely developed via racing and thoughtful mechanistic modelling and testing, and made with exquisite craftsmanship. The complex suspension system of springs and dampers comprises simple elements that are useful by chance, and also some well‐designed and expensive components and subassemblies for advantages in structural dynamics and ride quality. These chariots' spokes and joints have aircraft‐like damage tolerance, and are more sophisticated than those of any veteran car with wooden wheels. A substantially better overall design with the ancient materials of construction is difficult to visualize even if we apply our knowledge and computerized methods. This makes the Egyptian chariot an excellent example of original and advanced design, and a formidable challenge in further engineering investigations aimed at a full understanding of the ancients' achievements.
The effect of porosity on the fatigue life of cast aluminium‐silicon alloys*
Authors: GAO Y. X. , YI J. Z. , LEE P. D. , LINDLEY T. C. 
Published: June 2004

ABSTRACTFatigue strength optimization of cast aluminium alloys requires an understanding of the role of micropores resulting from the casting process. High cycle fatigue tests conducted on cast A356‐T6 show that the pore size and proximity to the specimen surface significantly influence fatigue crack initiation. This is supported by finite element analyses (both elastic and elastic–plastic) which demonstrate that high stress/strain concentration is induced by pores which are both large and near to the specimen surface. A new pore‐sensitive model based on a modified stress‐life approach has been developed which correlates fatigue life with the size of the failure‐dominant pore. The model prediction is in good agreement with experimental data.
Measuring stress intensity factors during fatigue crack growth using thermoelasticity
Authors: DÍAZ F. A. , PATTERSON E. A. , TOMLINSON R. A. , YATES J. R. 
Published: June 2004

ABSTRACTThermoelastic stress analysis has been developed in recent years as a direct method of investigating the crack tip stresses in a structure under cyclic loading. This is a consequence of the fact that stress intensity factors obtained from thermoelastic experiments are determined from the cyclic stress field ahead of a fatigue crack, rather than inferred from measurement of the crack length and load range. In the present paper the results of fatigue crack growth tests performed on welded ferritic steel plates are reported. From the results it can be observed that the technique is sensitive to the effects of crack closure and the presence of tensile and compressive residual stresses due to welding.
Monitoring fatigue degradation in austenitic stainless steels
Authors: KALKHOF D. , GROSSE M. , NIFFENEGGER M. , LEBER H. J. 
Published: June 2004

ABSTRACTDuring cyclic loading of austenitic stainless steel, microstructural changes occurred, which affected both mechanical and physical properties. For certain steels, a strain‐induced martensitic phase transformation was observed. The investigations showed that for the given material and loading conditions the volume fraction of martensite depended on the cycle number, temperature and initial material state. It was found that the martensite content continuously increased with the cycle number. Therefore, the volume fraction of martensite was used for indication of the fatigue usage. The temperature dependence of the martensite formation was described by a Boltzmann function. The martensite content decreased with increasing temperature. Two different heats of the austenitic stainless steel X6CrNiTi18‐10 (AISI 321, DIN 1.4541) were investigated. The martensite formation rate was much higher for the cold‐worked material than for the solution‐annealed one. All applied techniques, neutron diffraction and advanced magnetic methods allowed the detection of martensite in the differently fatigued specimens.