bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multivitamin‐mineral supplementation and age‐related cataract. The Italian‐American controlled clinical trial
Authors: MARAINI G 
Published: September 2008

Abstract Purpose To evaluate if a multivitamin‐mineral supplement at RDI dosage can prevent incidence and progression of age‐related cataract. Methods Randomized, double blind, single centre clinical trial. 1020 participants of Italian descent living in Parma, 55 to 75 years old, were assigned to placebo or to a daily tablet of Centrum. Lens status was assessed at baseline and at yearly follow‐up visits by lens photography.Primary outcome was a prespecified increase from baseline in N, C, or PSC opacity grades or cataract surgery. Secondary outcomes were increase in type‐specific opacity grades, cataract surgery, and visual acuity loss > 15 letters. Results After an average follow‐up of 9 +‐ 2.4 years there was a decrease in total lens events in participants assigned to Centrum (HR 0.82, 95% CI 0.68‐0.98, P = 0.03). Nuclear events were significantly less common (HR 0.66, 95% CI 0.50‐0.88, P = 0.004) and PSC events significantly more common (HR 2.00, 95% CI 1.35‐2.98, P =< 0.001) in participants taking Centrum. No statistically significant treatment effects were seen for cortical opacities, moderate visual acuity loss, or cataract surgery. Conclusion Lens events were less common in participants who took Centrum, but treatment had opposite effects on the development or progression of N and PSC opacities. This and the absence of effect on a functional outcome does not allow us to recommend the use of RDI nutritional supplement to affect the risk of cataract development (Ophthalmology 115;599,2008).
Mathematical models of intraocular pressure measurements and ocular rigidity
Authors: KOTLIAR K , KOSHITS IN , LANZL IM 
Published: September 2008

AbstractThe term ocular rigidity is widely used in ophthalmology. Generally it is assumed as a measurable physical parameter related to biomechanical properties of the whole eye globe. Formulas for clinical tonometry and tonography methods include the concept of ocular rigidity. Unfortunately ocular rigidity represents an elusive concept that means many things to many people. First of all, there is no consensual view on ocular rigidity in ophthalmology. The most of the formulas for ocular rigidity are based on discrete or continuous tonometric measurements in living or enucleated human eyes. Surprisingly ocular rigidity is measured in different units and has a different meaning by different authors. Finally, there is no clear consent between biomechanical engineers and ophthalmologists on the concept of ocular rigidity. In biomechanics parameters for the elasticity and viscoelasticity are accepted, which represent mechanical properties of a tissue an can consider its morphology. These are for example: Young’s moduli of the sclera, Poisson’s ratios of the cornea etc. Ophthalmological concepts on ocular rigidity are based on the consideration, that biomechanical properties of the corneoscleral shell are involved in the pressure‐volume relationship of the eye globe. Ocular rigidity defined in such a way climes to describe the total response of the eye without detailed considerations on its morphologic and material properties. In the proposed review several formulations of ocular rigidity are analysed and classified. It is attempted to link these conceptions with each other.
Assessment of ocular responce analyzer advantages for IOP measurements in children with progressive myopia
Authors: IOMDINA E , IVASHCHENKO ZH , TARUTTA E , EREMINA M 
Published: September 2008

Abstract Purpose To study IOP in children with progressive myopia and myopic adults 4‐9 years after photorefractive keratectomy (PRK) using ORA (Reichert) and to assess the influence of corneoscleral biomechanics on IOP measurement results. Methods Corneal‐compensated IOP (IOPcc), corneal hysteresis (CH), factor of corneal resistivity (FCR), IOP by Goldman (IOPG), corneal thickness and axial length were measured in 34 children (75 eyes) with low (27 eyes), moderate (31 eyes) and high (17 eyes) progressive myopia and 8 patients (16 eyes) with emmetropia or low hyperopia aged 7‐17, and 17 adults (28 eyes) with moderate and high myopia 6.5±0.2 years after PRK and 8 adults (16 eyes) of the same age (36.6±2.0 years) and myopia degree who had no refractive surgery. Results An insignificant (within the age norm) relative increase of IOPcc has been detected in children with moderate (17.6±0.7 mmHg) and high myopia (17.8±0.8 mmHg) as compared with low myopia (16.4±0.6). Values of IOPcc seem to provide a more exact reflection of the ophthalmic tonus in myopic eyes than IOPG. CH proved to be lower in moderate (10.9±0.3 mmHg) and high myopia (10.7±0.4 mmHg) than in low myopia (11.2±0.3 mmHg) and emmetropia (12.4±0.7 mmHg), while FCR remains practically unchanged. So, CH is related to biomechanical properties of sclera. In the late period after PRK, IOPcc (14.9±0.4 mmHg) and FCR (8.9±0.2 mmHg) are lower than without refractive surgery (resp. 18.4±0.8 and 10.5±0.4 mmHg), while CH shows an identical drop in both cases (resp. 9.4±0.2 and 9.8±0.4 mmHg) compared to norm, which testifies to surgically induced biomechanical changes of the cornea. Conclusion ORA reduces the impact of corneoscleral biomechanical properties on IOP measurements.
The estimation of intraocular pressure after refractive surgery. Statistical and simulation data
Authors: BAUER SM , KACHANOV AB , SEMENOV BN 
Published: September 2008

Abstract Purpose To estimate the change in intraocular pressure (IOP) measured by either Maklakov tonometer or by Goldmann tonometer after refractive surgery for myopia and hypermetropia. In contrast to Goldmann tonometer, which measures the IOP by estimating the force needed to apply for prescribed deformation of the cornea, with Maklakov tonometer IOP is measured by estimating the diameter of the circular contact area of the cornea and the flat bottom of a tonometer. Methods Numerical simulations have been carried out using finite element package ANSYS. The eye shell is modeled as two joint shells (cornea and sclera) with different mechanical properties. The results of mechanical simulation and statistical data were compared. For statistics the measurements of IOP were made for both eyes of 110 patients before and one month after corneal refractive surgery Results Applanation tonometry after refractive surgery for both myopia and hypermetropia shows reduction of IOP, since in both cases the bending stiffness of the cornea decreases. For some parameters of refractive surgery for myopia (with decreasing corneal thickness less than 0.1 mm) the reduction of IOP is correlated with central corneal thickness. But in general the current model predicts nonlinear relations between new central corneal thickness and IOP reading Conclusion All parameters of refractive surgery (the depth, the width and the place of ablation, the thickness of flap for Lasik surgery) have an effect on IOP reading obtained with both Goldmann and Maklakov tonometry. The results obtained by Goldmann tonometer are significantly more sensitive to all parameters of refractive surgery than those found with the Maklakov tonometer with load 10 g.
The mechanical response of lamina cribrosa to the elevated intraocular pressure
Authors: VORONKOVA E 
Published: September 2008

Abstract Purpose To consider the different mechanical aspects of the development of glaucomatous atrophy of the optic nerve fibres. Methods The Lamina Cribrosa (LC) is modelled as a continuous anisotropic plate with radial and angular nonuniformity. The solutions for LC with different degrees of nonuniformity can help reveal the structure of the LC, for which the glaucomatous damage is most probable to develop. In the second model, LC is assumed to be of multilayer shell of revolution with elastic ties between the layers. The varying of the LC strain of the optic nerve disk after decompression surgeries due to a dissection of the sclera channel paries is analyzed. The nonlinear shell theory is used to analyze deformations of the LC. Results The calculations of the stresses and deformations in the LC show that the shear deformation of the vertical element of the LC could cause the atrophy of the optic nerve fibres. Buckling in the nonaxisymmetric state in the neighborhood of the edge could also cause edemas at the periphery of the LC and the atrophy of the optic nerve fibres. It is shown, that after decompression surgeries the shape of the LC deflection becomes more shallow, its relative value decreases, as a result of the sclera refinement. However the absolute LC deflection increases. Conclusion All considered models confirm the mechanical genesis of glaucoma and help to evaluate the deflection of LC in normal state and after decompression surgeries.
Multifocal ERG and OCT in unexplained visual loss
Authors: BASTOS A , NOGUEIRA V , FERREIRA A , CRAVO I , NOVAIS M , CAMPOS F , PINTO F , CASTANHEIRA‐DINIS A , MONTEIRO‐GRILLO M 
Published: September 2008

Abstract Purpose To determine the value of multifocal ERG (mfERG) and optical coherence tomography (OCT) in the evaluation of patients with unexplained visual loss. Methods mfERG and macular OCT were obtained from six patients with unexplained visual loss (normal ophthalmoscopy, fluorescein angiography, full‐field ERG and brain CT scan) and four age and sex matched controls. Results Patients BCVA ranged from 20/32 to 20/125. When comparing to controls, patients showed significantly depressed mfERG amplitudes in rings R1 (121.7 vs 64.8; p 0.01) and R2 (42.6 vs 19.5; p 0.02). Foveal thickness, as measured by macular OCT, was also reduced, although not significantly (p 0.1). Conclusion Multifocal ERG allowed localization of the visual dysfunction to the central macula, in cases with hitherto unexplained visual loss.
Objective assessment of chromatic and achromatic pattern adaptation reveals the temporal response properties of different visual pathways
Authors: ROBSON AG , KULIKOWSKI JJ 
Published: September 2008

Abstract Purpose To investigate the temporal response properties of magnocellular, parvocellular and koniocellular pathways using contrast increment/decrement visual evoked potentials (VEPs). Methods Static achromatic and isoluminant chromatic gratings were generated on a monitor (Michelson contrast 0.05 to 0.6). Chromatic gratings were modulated along R/G or subject‐specific tritanopic confusion axes, established using a minimum distinct border criterion. Isoluminance was determined using minimum flicker photometry for a 1‐degree field. Achromatic and chromatic VEPs were recorded to contrast increments and decrements of 0.1 superimposed on the static gratings. Field size for Tritan gratings was restricted to 3‐degrees to minimize the effects of luteal pigment. Results Achromatic increment/decrement VEPs were positive in polarity and largely unaffected by high levels of static contrast at low spatial frequencies. Responses to finer achromatic gratings showed marked attenuation as static contrast was increased. Chromatic VEPs to R/G or Tritan chromatic contrast increments were of negative polarity and showed progressive attenuation as static contrast was increased. Chromatic contrast decrement VEPs were of positive polarity and less sensitive to pattern adaptation. Conclusion The relative contribution of sustained and transient response mechanisms to achromatic processing is spatial‐frequency dependent. Chromatic contrast increment VEPs are highly sensitive to pattern adaptation consistent with high stimulus selectivity and the sustained temporal response properties of the parvocellular and koniocellular pathways.
Pupil reactions in children with strabismic amblyopia in dependence of deviation value
Authors: BOYCHUK IM , BUSHUEVA NN , ROMANENKO DV , SLOBODYANIK SB 
Published: September 2008

Abstract Purpose To reveal the difference between pupil reactions in amblyopic children with and without menifest deviation Methods 51 patient with amblyopia aged 7‐12 y.o. were examined on the elaborated upillography device. There were 22% with amblyopia of high degree (average visual acuity and 64% of low and 14% of middle degree. Children had hypermetropic refraction;central monocular fixation in 27,eccentric in 18 cases. 32% of cildren had strabismus of different kind others had no manifest deviation (68%). The changes of pupil parameters during investigation of direct and consensual reaction on flashlight test and accommodative‐convergence response were conducted. With the help of elaborated device and corresponding software for pupillography method and STATISTICA for Windows 98. Results The significant difference was found in groups with and without manifest strabismus during direct fleshligh, the amplitude was larger in those who had manifest viation. The amplitudes of pupil constriction in consensual reaction on flesh light test were also larger in amblyopic patients without deviation, P<0,05. Latencies of pupil striction was almost equal on both eyes in patients without deviation but were significantly different in those, who had manifest deviation. After accommodative‐convergence response average value of pupil recovery was larger in patients without deviation in comparison with. Conclusion Patients without manifest deviation have disorders in reaction of pupil to direct flesh light test and accommodative response on the near object. Patients with deviation have consensual pupil reaction disorders that indicate on involvement of afferent but and efferent pathways of eye motility in such cases.
Accommodation insufficiency in children: are exercises better than reading glasses?
Authors: WAHLBERG M , CARLSSON R 
Published: September 2008

Abstract Purpose Purpose: The aim of the present study is to investigate which mode of therapy is the most effective in the treatment of accommodative insufficiency (AI). The two methods compared was plus lens (+1.00D) reading addition (PLRA) or spherical flipper (± 1.50D). Methods Methods: Twenty four subjects (mean age 10.3 years, 2.5 SD) participated. All subjects were diagnosed with AI. Ten subjects were treated with PRLA and 9, out of 14, subjects completed spherical flipper treatment. The treatment time was 8 weeks. Results Results: There was a statistical significant improvement in the accommodative amplitude with both regimes of treatment. However, accommodation did not reach normal values after only 8 weeks of treatment. The analysis between the two therapies did not reveal any statistical significant difference although spherical flipper treatment was found to have an overall larger effect. Conclusion Conclusions: The results of the present study show that both methods improve accommodative amplitude but there were no significant difference between the two methods.
Towards a blood test for diabetic retinopathy
Authors: SHALCHI Z , BUTT A , SMITH S , POWRIE J , JANIKOUN S , SWAMINATHAN R 
Published: September 2008

Abstract Purpose Diabetic retinopathy (DR) is the leading cause of blindness among adults of working age in the UK. Early detection and appropriate management can prevent severe visual loss in 95% of cases. However, current screening methods are costly and suffer from subjective grading. Nucleic acids have been shown to circulate in plasma, with levels raised in conditions of cell death such as cancer and trauma. This study aimed to quantify circulatory retinal‐specific nucleic acids, and to evaluate potential for their use in the assessment of DR. Methods Diabetic patients (n = 106) and healthy controls (n = 24) were recruited from the Diabetes and Ophthalmology departments at St Thomas’ Hospital. RNA was extracted from whole blood, with quantitative real‐time RT‐PCR used to quantify mRNA levels for rhodopsin and RPE65, two proteins expressed exclusively in the retina. Beta‐actin mRNA was used for normalisation. Results Rhodopsin, RPE65 and beta‐actin mRNA were detected in 100% of subjects. Circulating rhodopsin and RPE65 mRNA levels were higher in diabetic patients than healthy individuals (p < 0.02). Circulating rhodopsin mRNA was raised in all DR groups compared to healthy individuals, irrespective of presence or severity of DR (p < 0.02). With respect to healthy controls, circulating RPE65 mRNA levels were higher in diabetic patients with background and proliferative DR (p < 0.02). Patients with active proliferative DR (neovascularisation, vitreous and pre‐retinal haemorrhage, or retinal detachment) possessed higher RPE65 mRNA and lower rhodopsin mRNA levels than those with quiescent disease (p < 0.01). Conclusion There is significant potential for use of these markers to screen for the presence of DR in diabetic patients in a quantitative manner using a blood test.
Risk markers for progression of mild nonproliferative retinopathy to clinically significant macular edema in type 2 diabetic patients
Authors: PEREIRA I , NUNES S , RIBEIRO ML , BERNARDES R , CUNHA‐VAZ J 
Published: September 2008

Abstract Purpose To determine risk markers for the development of clinically significant macular edema (CSME) needing photocoagulation treatment in type 2 diabetic patients with mild nonproliferative retinopathy (NPDR), during a 7‐year period. Methods Fifty‐one type 2 diabetic patients with mild NPDR, followed‐up for 2 years as controls of diabetic retinopathy clinical trials, were selected. Patients underwent ophthalmological examinations every 6 months, including stereoscopic color fundus photography, fluorescein angiography and vitreous fluorophotometry, and were metabolically controlled. These patients were thereafter followed‐up for the next 5 years by conventional general and ophthalmological care. Results At the end of the 7‐year follow‐up period, 8 patients developed CSME, needing photocoagulation treatment. These patients presented a higher microaneurysm (MA) formation rate at the first year of follow‐up (p<0.001), a higher blood‐retinal barrier (BRB) permeability value (p=0.042), an abnormal foveal avascular zone (FAZ) contour on fluorescein angiography (p=0.009) and a higher HbA1C level at baseline (p=0.001). Conclusion Microaneurysm formation rate higher or equal to 3 MA/year, BRB permeability values over or equal to 4.0 nm.s‐1, evidence of abnormalities in the FAZ, and hemoglobin A1C levels at baseline, are risk markers for progression of NPDR to CSME in patients with type 2 diabetes.
Screening diabetic retinopathy using a wide field imaging system
Authors: ARNDT C , NABHOLZ N , BOUSQUET E , NGUYEN F 
Published: September 2008

Abstract Purpose The wide field (200°) imaging system (Optos, Great Britain) using a scanning laser ophthalmoscope (SLO) enables to visualize a large part of the retina including the periphery. The present study was designed to evaluate the imaging system for screening purposes in diabetic retinopathy. Methods The SLO system was used in diabetic patients in stationary care. Screening for diabetic retinopathy was performed: An undilated and dilated retinal biomicroscopy was performed by a senior ophtalmologist. An undilated SLO image was taken by an orthoptist in training. The images were reviewed by a resident masked to results of the previous retinal biomicroscopy. The results of the clinical examination were compared with the results of the SLO image analysis. Results A total of 251 patients were evaluated (n=503 eyes). Of the retinal lesions detected on the undilated SLO images, the undilated retinal biomicroscopy missed 24% and the dilated retinal biomicroscopy 11%. None of the retinal lesions detected with the undilated retinal biomicroscopy were missed on the SLO images. Conclusion The diagnostic rate of diabetic retinopathy using undilated SLO images was significantly higher when compared with the diagnostic rate of undilated and dilated retinal biomicroscopy. Further work is necessary to evaluate the diagnostic yield of the wide field SLO system in comparison with standard non mydriatic retinography procedures.
Enhanced levels of VEGF and reduced levels of VEGFxxxb in the vitreous of patients with retinal vein occlusion
Authors: MICHELS D , RENNEL ES , FELTGEN N , MARTIN G , STAHL A , HANSEN LL , AGOSTINI HT 
Published: September 2008

Abstract Purpose To investigate the role of VEGF and VEGFxxxb in the pathogenesis of Central Retinal Vein Occlusion (CRVO) and Branch Retinal Vein Occlusion (BRVO). Methods In a cross sectional study we analyzed the vitreous of patients with CRVO (ischemic and non‐ischemic) and BRVO. A group of patients with vitrectomy not due to CRVO/BRVO served as control. The vitreous of 25 patients with CRVO, of 28 patients with BRVO and of 32 patients with no sign of CRVO/BRVO were analyzed using ELISA for VEGF and VEGFxxxb. Results The ratio CRVO/controls for VEGF was 5.5, and 2.5 in BRVO/controls. In comparison the VEGFxxxb ratio in CRVO/controls was 0.19, and 0.85 in BRVO/controls. Conclusion Total VEGF levels in patients with CRVO and BRVO are significantly upregulated compared to controls. The finding of a significantly down‐regulated antiangiogenic VEGFxxxb in patients with CRVO is similar to the altered balance of the splice variants found in vitreous samples of patients with proliferative diabetic retinopathy.
Ametropia in children with regressed retinopathy of prematurity
Authors: BHATT UK , ANWAR S 
Published: September 2008

Abstract Purpose Main aims of this study were:(1)To identify the pattern of refractive changes in children with different degrees of pre‐threshold retinopathy of prematurity (ROP). and (2)To establish whether long term follow‐up is necessary for these children? Methods ROP screening notes of all premature babies born between Jan 2001 to Jan 2005(5 years) within a defined geographical area (Leicestershire) of the UK and fulfilling the national ROP screening guidelines were reviewed retrospectively. According to the severity, we graded the pre‐threshold ROP as follows: (1)Grade1‐ Any disease restricted to zone 3 or Stage I or II in zone 2, (2)Grade2‐ Stage II+ or III disease in zone 2, and (3)Grade3 ‐ Stage III+ disease in zone 2 Any zone 1 disease. Eyes of matched eyes were used as controls (same gestational age and weight matched children who were premature but without ROP). Cycloplegic refraction data (minimum follow up period‐ 24 months) on these children were then collected through the clinic notes. The results were compared statistically. Results Refractive status results (at 24 months age) were available for 116 eyes in 62 children (Electronic search + Case notes review). Eyes were assigned to our predefined grades: Grade1:60 eyes(32), Grade2:34 eyes(18), and Grade3:22 eyes(12). The results of cyclopegic refraction (Mean spherical equivalent, Range) were as follows: Grade1:0.59(‐1.75 to +3), Grade 2: ‐0.04(‐4.5 to +2.25), and Grade 3: ‐1.59 (‐7.5 to +1.75). Statistically, refractive outcome of Grade 2 and 3 ROP children were different from controls. Conclusion In pre‐threshold ROP, the trend of myopia is directly proportional to the severity of ROP. We recommend that regular follow up is necessary for Grade 2 and 3 ROP babies but no follow up required for babies with Grade 1 disease.