bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fixation stability during the Rarebit Fovea Test
Authors: NILSSON M , GRANATH H , WAHLBERG M , WANGER P , BRAUTASET R 
Published: October 2007

Abstract Purpose: To evaluate the fixation stability in normal subjects during the Rarebit Fovea Test (RFT). The RFT is a computerized test designed to evaluate the integrity of the central retinal detector matrix. Methods: 11 healthy subjects with visual acuity ≥ 1.0, were examined, using the standard RFT setup, i.e. stimulus presentation on a 17 inch computer screen at a viewing distance of 2 m. The test principle is to briefly present one or two very small (< 0.5’) and bright dots in the central 4x3º visual field. The subject responds by clicking the computer mouse once or twice. The test time is approximately 90 sec and audio‐stimulation is given each time the fixation target is rotated in order to enhance central fixation. Fixation stability was measured during the RFT test using the PowerRefractor™ (Purkinje image eye‐tracking).One eye in each subject was tested. All measurement data were analyzed using SPSS and Matlab. Results: All subjects had normal RFT test results, i.e. close to 100% of the presented dots were perceived. 97% of the testing time fixation was maintained within 1.38° and 100% of the time within 2.76°. Conclusions: Normal subjects appear to maintain stable fixation during the RFT. Further studies of patients with minor macular changes are underway.
Prevalence of exfoliation syndrome in Pella‐Greece
Authors: TSIRONI S , BENOS A , ZAFIRIADIS A , MICHAEL R , TSAOUSIS G , MIKROPOULOS D , KONSTAS AGP 
Published: October 2007

Abstract Purpose: To determine the prevalence of exfoliation syndrome (XFS) in the area of Pella, Greece. Methods: We studied a cluster, stratified sample of 700 individuals >45 years old (350 women and 350 men), representative of the population of Pella County. A comprehensive protocol recorded exfoliation findings before and after pupillary dilatation, as well as signs commensurate with possible XFS. The intraocular pressure (IOP) was recorded in all cases. Results: Typical XFS was detected in 10% of the examined persons. The percentage of clinically evident XFS rose from 0% in the 45‐54 age group, to 2% for the 55‐64 age group, 21.3% for the 66‐74 age group and 34% for the >75 group of patients. There was no significant difference between the two sexes concerning the prevalence of XFS. Mean IOP was higher (20.04 mmHg) for the individuals with XFS versus those without (15.37 mmHg). Twelve patients with XFS (17.14%) had previously undiagnosed exfoliative glaucoma (XFG). Among the 70 persons with XFS, 60 (94.2%) had lens opacities, while 224 (35.5%) among the 630 persons without XFS had cataract. Conclusions: The prevalence of XFS in the area of Pella was determined to be 10% for individuals older than 45. There is strong correlation between XFS, glaucoma and cataract.
Neuropeptide y protects retina neural cells from ecstasy‐induced neurotoxicity
Authors: AMBROSIO AF , ALVARO AR , MARTINS J , FERNANDES E , BASTOS ML , CARVALHO F , CAVADAS C 
Published: October 2007

Abstract Purpose: The recreational drug 3,4‐methylenedioxymethamphetamine (MDMA; ecstasy) causes neurotoxicity in the brain. Ecstasy consumers may experience visual effects, and significant levels of MDMA were detected in the human vitreous after lethal doses. It is also known that Neuropeptide Y (NPY) can be a neuroprotective agent. In this study, we investigated the putative neurotoxic effect of MDMA in retina neural cells, and the potential neuroprotective effect of NPY. Methods: Rat retina neural cell cultures were prepared from newborn Wistar rats. The cells were exposed to MDMA (100‐1600 μM) for 24 or 48 h, at 37 ºC or 40 ºC. Cell viability was evaluated by MTT assay and propidium iodide staining. Retinal cells were identified by immunocytochemistry. Results: MDMA decreased retinal cells viability in a concentration‐, time‐ and temperature‐dependent manner. The toxic effect of MDMA non‐selectively affected different retinal cells (neurons and glial cells) and was dependent on caspase activation. In addition, the toxic effect was significantly reduced by ketanserin, a 5‐HT2A antagonist, and by NPY, but the protective effect of NPY was more pronounced. Conclusions: These results show that MDMA is neurotoxic to retina neural cells, and the toxic effect can be exacerbated by hyperthermia. The toxicity of MDMA is partially mediated by the activation of the 5‐HT2A receptor. Also, NPY is a potent neuroprotective agent against MDMA‐induced retina cell degeneration. These findings extend previous findings about the dangers of MDMA consumption. Further studies and a closer follow‐up on the visual status of human consumers are evidently necessary. Support: FCT (SFRH/BD/12900/2003) and Fac. Medicine, Univ. Coimbra (GAI 01/07), Portugal
Superoxide dismutase, glutathione reductase and glutathione peroxidase activities in the whole blood of exfoliation syndrome and exfoliation glaucoma patients
Authors: BLOMSTER HT , NURMI A , PUUSTJÄRVI T , KAIKKONEN J , KONTKANEN M , HILTUNEN R , TERÄSVIRTA M , SALONEN JT , VILPPO T 
Published: October 2007

Abstract Purpose: Oxidative stress is implicated in the pathogenesis of both exfoliation syndrome (XFS) and exfoliative glaucoma (XFG). We aimed to study the whole blood levels of endogenous antioxidative enzymes, superoxide dismutase (SOD, glutathione reductase (GR) and glutathione peroxidase (GPX) in XFS and XFG patients. Methods: Deep frozen whole blood samples at ‐71 Celcius collected from 35 XFS patients including 11 XFG patients and 35 age‐ and gender matched controls, all of them operated on cataract, were analyzed for SOD, GR and GPX activity by using a commercial kit (Ransod, Randox). For statistical analyses, Wilcoxon Signed Rank Test was used. Results: The whole blood enzyme activities in the SOD, GR and GPX in XFS/XFG groups were 119,6+‐19,1 U/ml, 498,4+‐105,6 U/L and 7281,5+‐1341,4 U/L, and in controls, 121,4+‐22,5 U/ml, 536,8+‐126,2 U/L and 7689,8+‐1843,9 U/L, respectively. In the statistical evaluation, the respective P‐values were 0,467, 0,169 and 0,263. In the subgroup of XFGs, apart from the XFS/XFG group, there were no statistical differences in the whole blood enzyme activities of SOD (p=0,594), GR (p=0,522) or GPX (p=0,957). Conclusions: The current study showed no significant differences in the whole blood enzyme activities in SOD, GR or GPX in XFS/XFG patients as compared to control group. This may implicate a proper function of these endogenous antioxidative enzymes dispite of increased oxidative stress known to be involved in XFS and XFG.
NGF topical administration in dogs affected by spontaneous keratoconjunctivitis sicca
Authors: DODI PL , ZANOTTI C , COSTA N , ALOE L 
Published: October 2007

Abstract Purpose: To study the effect of Nerve Growth Factor (NGF) on spontaneous keratoconjunctivitis sicca (KCS) in dogs and to evaluate the potential therapeutic action of this molecule. Methods: The present study has been conducted on a sample of randomized dogs affected by spontaneous KCS. It consists of 6 cases (12 eyes), various ages (from 2 to 10 years old), different sexes (4 males‐ 2 females). All dogs showed: different stages of muco purulent filaments and redness; they were negative to fluorescein; Schirmer tear test I (STT I) on right eye was 5,8 ± 2,0 mm/1 min on left one was 6,0 ± 1,4 mm/1 min; cytology showed many inflammatory cells. The dogs were topically treated with purified murine NGF diluted in paraffin oil (value: 50 microgram/ml) for 4 weeks (2 drops every 12 hours). Results: The result of these studies showed a significant improvement as evaluated by STT I. Thus, the right eye was 13,1 ± 2,4 mm/1 min (p < 0,05), left eye was 14,0 ± 2,4 mm/1 min (p < 0,05). Moreover, dogs treated with NGF displayed decreased purulent corneal secretion and redness and improvement of corneal transparency. Cytology analysis indicated a significant reduction in the number of corneal inflammatory cells. Conclusions: This report demonstrated that NGF is involved in the regulation of tears production, most probably by acting on tear‐producing cells. NGF caused also a marked anti‐inflammatory action of the dog’s cornea. This result confirmed and extended previous evidences on human dry eye and previous findings suggesting a potential therapeutic utility of NGF in spontaneous KCS affecting dogs. Neverthless, further clinical studies are necessary to assess the consistency of this clinic approach.
The influence of pupil size, accommodation and higher order aberrations on the retinal image of a Rarebit Fovea Test‐stimulus
Authors: WAHLBERG M , BRAUTASET R , UNSBO P , LINDSKOOG PETTERSSON A , NILSSON M 
Published: October 2007

Abstract Purpose: To study the influence of pupil size, accommodation and higher order aberrations on the retinal image of the small test stimulus (<0.5´) used in the Rarebit Fovea Test (RFT). Methods: Eleven subjects aged between 22‐36 years participated. All subjects had a corrected visual acuity of 6/6 or better and a refractive error within ± 6 diopters. A PowerRefractorTM measured pupil size and accommodation continuously in all subjects during performance of the RFT. Aberrations were measured with a Zywave aberrometer and Matlab software was used for analysis. Results: Mean variation in accommodation was 0.4D (range 0.22‐0.61D) and mean pupil size was 6.1 mm (range 5.0‐7.8 mm). The aberrations induced a smearing of the retinal image to ~3.5x the stimulus size. When the variation in accommodation was added the total smearing of the retinal image increased to ~4x the stimulus size. Conclusions: The minimum retinal image size of a RFT stimulus is given by aberration and defocus rather than the actual size of the object (stimulus).
A new universal rat restrainer for in vivo exposure to UVR without anesthesia
Authors: GALICHANIN K , HUANG S , WANG J , ZHANG Y , MODY V , LÖFGREN S , SÖDERBERG PG 
Published: October 2007

Abstract Purpose: Immobilization of rats is required in many psychological and physiological experiments with rats. The aim was to invent a universal device allowing for adaptation of rats of wide age range and to maximize convenience for in vivo exposure to ultraviolet radiation under un‐anesthetized conditions. Methods: Eighty six‐week‐old Sprague‐Dawley albino female rats were progressively familiarized daily with the restraining device seven days prior to exposure in order to acquire conditioned reflex of place and reduce stress of the awake rodents. In this training period, the animals were handled in the rat restrainer for 5 to 15 minutes during the first day and restrained for 5, 10 and 15 minutes during the second, third and fourth days, respectively. After initial habituation ten minutes preceding the exposure, the animal was fixed in the rat restrainer. Each animal was unilaterally exposed to 8 kJ/m2 UVR‐300nm for 15 minutes without narcosis. After exposure the animal was unfixed and then replaced into the cage. Results: All rats were acclimatized to the limited activities in the rat restrainer during exposure time. The device prevents both intensive head movement and body rotation, making the device effective for in vivo exposure to UVR without anesthesia. Conclusions: The currently designed rat restrainer reduces mobility of rats without need of sedatives, enabling our device to be useful in future projects involving chronic repeated in vivo exposure of the eye to ultraviolet radiation.
Foveal function in children treated for amblyopia
Authors: AGERVI PH , NILSSON M , MARTIN L 
Published: October 2007

Abstract Purpose: To evaluate foveal function in children treated for amblyopia using best‐corrected visual acuity (BCVA) and the Rarebit Fovea Test (RFT). Methods: Nineteen children, aged 7‐9 years, previously treated for monocular amblyopia were examined with BCVA and RFT. Twenty‐three healthy, age‐ and gender matched children served as controls. BCVA was measured with a line letter chart. The foveal function was measured with the computerized RFT, designed to detect minor defects in the retino‐cortical detector matrix. In all amblyopic eyes, the non‐amblyopic eye was tested first. Results: The median decimal BCVA was significantly lower in the amblyopic eyes (0.8, range 0.2‐1.0) compared to the non‐amblyopic eyes (1.0, range 0.8‐1.3, p = 0.0005) and to both eyes in the control group (1.0, range 1.0‐1.3, p<0.0001 and p<0.0001, respectively).The RFT results were significantly (p=0.0012) lower in the amblyopic eyes (second tested) compared to the second, but not the first, tested eyes in the control group. In this group the second tested eye showed better RFT results compared to the first tested eye, but the difference was not statistically significant. A weak (r2=0.25) but significant (p=0.028) correlation was found between BCVA and RFT results in the amblyopic eyes only. Conclusions: The study demonstrated a difference in foveal function, measured with RFT, in amblyopic eyes, when tested after the non‐amblyopic eye, compared to the second tested eye in age‐matched controls. This finding may be interpreted as a sign of reduced function in the amblyopic eye or as lack of training effect in amblyopic subjects.
Aberration controll with contact lenses
Authors: LINDSKOOG PETTERSSON A , LUNDSTROM L , UNSBO P , JARKÖ C , ALVIN A , BRAUTASET R 
Published: October 2007

Abstract Purpose: To investigate and compare the reduction in ocular aberrations with standard hydrogel contact lenses (i.e., lenses not designed to control aberrations) and with aberration controlled hydrogel and silicon‐hydrogel contact lenses. Methods: The aberrations with and without contact lenses were measured in 42 subjects between 20 and 37 years of age using a Zywave wave front sensor (B&L). 22 subjects were fitted a standard contact lens and an aberration controlled hydrogel lens. The remaining 20 subjects were fitted aberration controlled silicon‐hydrogel lenses Results: With the standard lens the aberrations were controlled (i.e., close to zero) with a 4.0 mm pupil. Whereas, with both the aberration control lenses the residual spherical aberrations became negative. The reduction in aberrations differed significantly (p<0.05) between all lenses. Conclusions: Since aberration controlled contact lenses in many subjects overcorrect the spherical aberrations when the pupil size is normal (~4.0 mm) we suggest measuring wave front aberrations in each patient both with and without contact lenses in order to achieve the desired effect.
Keratocyte repopulation in UVB‐exposed thioltransferase knockout mice
Authors: PODSKOCHY A , ZHANG Y , HO YS , LÖFGREN S 
Published: October 2007

Abstract Purpose: Thioltransferase is involved in cell protein homeostasis and DNA synthesis. It inhibits apoptosis and stimulates cell proliferation. Keratocyte repopulation after ultraviolet B (UVB) damage was studied in corneas of thioltransferase (‐/‐) mice. Methods: Six wild type mice and six thioltransferase (‐/‐) mice corneas were exposed at 300 nm UV‐radiation at a dose producing damage in the corneal stroma (8 kJ/m2). Animals were killed 3 and 7 days after exposure. Corneas were processed for light microscopy. Results: All corneas of wild type mice and thioltransferase (‐/‐) mice showed extensive damage 3 days after UVB exposure. Keratocytes disappeared throughout the entire thickness of the UVB‐damaged central stroma. Corneal thickness was nearly doubled compared with non‐treated control corneas. However, 7 days after UVB exposure corneas of wild type mice were almost completely repopulated by keratocytes, only superficial ¼ of the stroma was still free of keratocytes. Corneal thickness was almost normal. Corneal stroma in the thioltransferase (‐/‐) mice 7 days after UV exposure was still not repopulated by keratocytes and the corneas were still very thick. Conclusions: The keratocyte repopulation in thioltransferase (‐/‐) mice is delayed. Thioltransferase seems to play an important role in the corneal wound healing and keratocyte repopulation after UVB induced damage.
Methodology of retinal straylight assessment
Authors: VAN DEN BERG TJTP 
Published: October 2007

Abstract Purpose: The psychophysical technique of “Compensation Comparison”, embedded in the C‐Quant instrument for clinical assessment of retinal straylight will be demonstrated. Retinal straylight is the cause of complaints such as glare hindrance and contrast loss. It results from disturbances in the optical media. Its assessment helps to decide on surgery of (early) cataract, or to evaluate corneal or vitreal problems. Methods: The subject’s task is to compare in 20 short presentations two flickering half fields, and to indicate with push buttons which one flickers more strongly. Added value in comparison to visual acuity was assessed in 2422 active drivers of the European GLARE study. Repeatability of the obtained straylight value was tested for 17 naive subjects and several groups of patients. Absolute measurement precision of the C‐Quant was tested using a scattering sample with known straylight value in front of the eyes of the 17 naive subjects. Results: Many individuals were found to suffer from increased straylight that is undetected in visual acuity: in 6% of cases with decimal visual acuity > 0.5 straylight was increased more than 4 times compared to normal. A psychometric function was derived and fitted to the patient responses, resulting in a straylight value including a reliability estimate. Repeated measures standard deviation for the method is about 0.07 log units, to be compared with differences of 1.0 log units or more units with (early) cataract or corneal disturbances. The check using known scatter samples showed virtually perfect (0.01 log units difference) correspondence. Conclusions: Absolute precision and repeated measures standard deviation is very good compared with differences in the population. Straylight measurement promises important extra diagnostic power.
Effects of UDP on ARPE cells: possible involvement of P2Y6 receptors
Authors: JUDICE DE MENEZES RELVAS L , BOUFFIOUX C , MARCET B , COMMUNI D , BLERO D , BRUYNS C , CASPERS L , BOEYNANS JM , WILLERMAIN F 
Published: October 2007

Abstract Purpose: We have studied the effects of nucleotides (ATPγS, UTP and UDP) on human retinal pigmental cells, in relation to their expression of functional P2Y receptors. Methods: ARPE cells were grown in culture and stimulated with ATPγS, UTP and UDP. Cell proliferation was analysed by BrdU incorporation. Calcium flux and cAMP were measured by fluorometry and radio‐immunoassay. IL‐8 production was investigated by semi‐quantitative RT‐PCR and ELISA. P2Y2, P2Y4 and P2Y6 expression was analysed by RT‐PCR. Results: UDP inhibited ARPE cell proliferation while ATPγS slightly stimulated it and UTP had no effect. This differential effect suggests the expression of other P2Y receptors than the already described P2Y2. Accordingly we detected transcripts for the P2Y6 receptor, which is a UDP receptor. UDP induced a calcium flux, like ATPγS and UTP, but no cAMP production. All nucleotides stimulated IL‐8 secretion. Conclusions: Our results suggest that ARPE cells express functional P2Y6 receptors.
Corneo–conjunctival leukoplakia: histology and confocal microscopy
Authors: MALANDRINI A , FRUSCHELLI M , TRAVERSI C , MOTOLESE PA , MARTONE G , MOTOLESE E 
Published: October 2007

Abstract Purpose: To explore corneo‐conjunctival leukoplakias using in vivo confocal microscope and tocompare images to histology and impression cytology specimens. Methods: Twenty‐nine patients affected by corneo‐conjunctival leukoplakia, after evaluation with slit lamp exam, were investigated with the Heidelberg Retina Tomograph II, Rostock Cornea Module. Subsequently a diagnostic excision or impression cytology of the cornea and/or conjunctiva was performed. Results: Histology identified seventeen Pterygia, six Pingueculas, two limbal stem cell deficiency (LSCD), one suture‐related corneal vascularization, one cicatricial Pterygoid and two corneal intraepitelial neoplasias (CIN). Confocal microscopy was compared to histopathologic sections and impression citology specimens.In all patients typical white colour of lesions was attribuable to a different degree of reactive hyperkeratosis.The main pathological features were visible on our confocal microscopy images: infiltration of conjunctival tissue surrounding lesions, vascularization, cellular morphology and activity, changes in extracellular matrix and modifications of limbar architecture. Conclusions: Confocal microscopy may be a useful aid for diagnosis and follow up in primitive and secondary corneo‐conjunctival lesions. However the ability to provide high resolution, real‐time images of the full thickness of the living human cornea and conjunctiva is strictly dependent on surface transparency and additional studies are required to establish exact correlations between confocal microscopy images and histopatology.
Short‐term effect of topical brimonidine tartrate on intrastromal pressure. an animal study
Authors: BOLIVAR G , TEUS MA , GUTIERREZ C , CASTEJON MA 
Published: October 2007

Abstract Purpose: To evaluate the effect of topical brimonidine tartrate on the intrastromal corneal pressure (ICP) , due to it have been postulated that the brimonidine tartrate could have an adverse effect on postoperative flap adherence to the stromal bed after LASIK surgery, and that the endothelial pump plays an important role in flap adhesion. Methods: Interventional, prospective study. The ICP was recorded for 45 minutes in eight eyes of rabbits treated with topical brimonidine tartrate three times daily for three consecutive days and in eight rabbit eyes treated with artificial tears (control group). All the measurements were performed by the same masked investigator. Results: The ICP averaged ‐4±2.9mmHg, ‐6.7±3mmHg y ‐9±4.5mmHg at 15, 30 and 45 minutes in the control group, respectively. In the study group (brimonidine treated eyes), the ICP readings were +2.75±2.9mmHg, ‐2.5±3mmHg y ‐8.5±5mmHg at the same time points, respectively. The differences in the ICP between both groups were statistically significantly different at 15 minutes (p=0.01), but neither at 30 nor 45 minutes (p=0.2 and p=0.8 respectively). Conclusions: The acute treatment with brimonidine tartrate produces significant changes in the ICP. This changes could help to explain the alteration in the flap adherence that have been reported.
Correctable and non‐correctable refractive error in a population of young men in Poland
Authors: NOWAK MS , GOS R , SMIGIELSKI J 
Published: October 2007

Abstract Purpose: To evaluate the prevalence of non‐correctable refractive error in a representative sample of Polish young men. Methods: A retrospective study of medical records of Military‐Medical Commission of Lodz, Poland. Distance visual acuity (VA) was assessed in 105017 men examined during period 1993‐2004. Visual acuity was checked on Snellen's charts without vision correction. We chose for the study a representative sample of 994 induviduals. Refraction data were obtained of those men who had impaired distance vision‐ presenting VA of below 6/12 in any eye. Non‐correctable refractive error was defined as the best corrected visual acuity (BCVA) of below 6/12 in one or both eyes. We use statistic analysis to estimate the results in a whole population of young men examined during researched period. Results: Mean age of researched individuals was 22.46 +/‐ 4.29 . Overall 13.28% subjects had impaired distance vision. After refraction, 90.15% of them could achieved VA of 6/12 or better with corrective lenses. Non‐correctable refractive error was found in 9.85% of men with impaired distance vision. Extrapolating these results to the whole population we estimate that 1.21% of Polish young men have non‐correctable refractive error‐ BCVA of below 6/12 in one or both eyes. Correctable refractive error was mainly due to myopia (78.10% right eye and 83.02% left eye). Conclusions: The overall non‐correctable refractive error had a relatively low prevalence (1.21% of population). Appropriate refractive correction improved distance VA in 90.15% subjects with impaired distance vision. The commonest refractive error was myopia.