bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sub‐Tenon infiltration or classical analgesic drugs to relieve postoperative pain
Authors: Calenda Emile , Muraine Marc , Quintyn Jean Claude , Brasseur Gérard 
Published: April 2004

Abstract Background: In a prospective randomized double‐blind study, the analgesic effect produced by sub‐Tenon infiltration was compared with classic analgesic drugs in patients scheduled for posterior segment surgery under general anaesthesia. Methods: One hundred patients were randomized into two groups of 50. One group received sub‐Tenon infiltration (group 1) with 3 mL of bupivacaine 0.50% by the surgeon before the end of the surgery and the other (group 2) received only classical analgesic drugs postoperatively. A visual analogue scale (VAS) (graded from 1 to 10) was used to assess pain. For both groups, when VAS was between 1 and 3 paracetamol (3 g/24 h) associated with ketoprofen (200 mg/24 h) was given; between 3 and 6 nalbuphine (0.2 mg/kg slowly intravenously repeated every 4 h if necessary) was given; and over 6 morphine was given. Morphine 1 mg was injected every 2 min until VAS below 3 was obtained. Results: All patients in group 2 (control) experienced pain in the recovery room period; however, no patient in group 1 required analgesic drugs in the first 6 h after the sub‐Tenon infiltration. In the recovery room period, the VAS pain score in patients who received sub‐Tenon infiltration (group 1) was 0.6 ± 1.3 (mean ± SD) compared to 3.4 ± 2.2 in group 2. The difference was statistically significant (P = 0.000001). All patients in group 2 asked for analgesic drugs in the recovery room, some of whom required morphine. Despite the administration of drugs the pain score was statistically higher in group 2. Between the end of the recovery room period and the 6th hour, the VAS pain score in group 1 was statistically lower. From the 6th until the 24th hour, the pain score was not statistically significantly different between the groups. Regarding consumption of analgesic drugs from the recovery room until the 24th hour, the consumption of level 1 analgesic drugs (paracetamol, ketoprofen) and level 3 (morphine) was statistically lower in group 1 (P = 0.0009). The difference was not significant for level 2, probably because the number of patients was not sufficient. Conclusion: Sub‐Tenon infiltration with 3 mL of bupivacaine 0.50% offers excellent postoperative analgesia for about 6 h and is an excellent alternative to classical drugs. Furthermore, it is highly reliable and safe.
A retrospective review of the associations between amblyopia type, patient age, treatment compliance and referral patterns
Authors: Chua Brian E‐G , Johnson Kim , Frank Martin FRANZCO  
Published: April 2004

Abstract Aim: To review presenting ages, referral sources, amblyopia type and treatment compliance in children attending a typical public hospital ophthalmology clinic with no formal amblyopia screening program in place. Methods: One hundred and twenty‐seven children attending the outpatients clinics of The Children's Hospital at Westmead for amblyopia management between January 2001 and May 2003 were reviewed. Presenting age, amblyopia type, referral source, treatment prescribed and compliance achieved were analysed using means, 95% confidence intervals (CI), and Mantel−Haenszel χ2 statistic. Results: General practitioners and paediatricians provided most referrals. The mean presenting age was 32.9 (95% CI 29.0−36.9) months. There was no significant association between presenting age and amblyopia type (χ2 = 6.00, P = 0.11, d.f. = 3), but a trend was found with deprivation amblyopia identified earliest, and pure anisometropic amblyopia identified latest (χ2 = 5.65, P = 0.02, d.f. = 1). Compliance to patching did not differ significantly between sexes, with calculated aggregate compliance of 67.3% (95% CI: 59−75%) for boys and 66.3% (95% CI: 60−73%) for girls. Compliance to patching also did not differ significantly between amblyopia types (χ2 = 3.61, P = 0.3, d.f. = 3). Compliance was best among younger and older children, and worst among those aged 15−30 months. There was no association between patching compliance and treatment duration. Conclusion: Amblyopia is a preventable form of blindness. A multidisciplinary approach must be taken. Resources and education should be targeted at general practitioners and paediatricians who have the greatest opportunities to perform amblyopia screening. Teachers are an important resource in identifying cases missed at previous informal screening opportunities. Amblyopia treatment must be intensified and individualized between the ages of 15−30 months when compliance is poorest.
Diode laser treatment of pre‐threshold and threshold retinopathy of prematurity
Authors: Lee Graham A , Hilford David J , Gole Glen A 
Published: April 2004

Abstract Purpose: Retinopathy of prematurity (ROP) is a sight‐threatening condition of premature infants. This study aimed to investigate the efficacy of diode laser photocoagulation in the treatment of pre‐threshold and threshold ROP. Methods: A retrospective review was conducted of patients who underwent diode laser treatment for ROP by one author (GAG) from 1992 to 2000. During this time, 2137 babies <1500 g birthweight or <32 weeks post‐conception age were examined. Results: Seventy‐six eyes in 40 infants (20 male, 20 female) were treated for ROP. Treatment was performed on average at 37 weeks post‐conception age (range 31−50 weeks, SD = 3.2). The number of burns per eye for the first session of laser ranged between 193 and 1937 (mean 933), with power ranging from 200 to 1000 mW (mean 484). Eighteen (45.0%) of these 40 infants underwent a second session of laser (mean number of burns 683, range 167−1618), which was performed in 29 (38.2%) of the 76 eyes that initially underwent laser treatment. Complete regression was observed in 61 eyes (80.3%), occurring on average at 39 weeks post‐conception age (range 35−45, SD = 2.2). Six (7.9%) eyes progressed to stage IVA disease, two (2.6%) to stage IVB and three (3.9%) to stage V ROP. In the latter part of the study as the number of laser burns per eye increased it was found that the number of patients requiring a second session of laser treatment decreased, with no adverse outcomes observed in the last 3 years of the study. At last follow up, the average refractive error in the treated eyes was −0.40 D spherical equivalent (range −12.75 D to +4.25 D, SD = 3.0). The degree of myopia induced showed no significant correlation with the number of laser burns administered. Conclusion: Diode laser treatment is able to stop progression of ROP in the majority of cases.
Medial canthal tendon repair for moderate to severe tendon laxity
Authors: Clement Colin I , O'Donnell Brett A 
Published: April 2004

Abstract Background: Medial canthal tendon laxity is a common cause of epiphora and ocular irritation. It is difficult to treat due to the proximity of the lower canaliculus and punctum to the tendon. Methods: The results of a prospective series of patients with involutional medial canthal tendon laxity between 1997 and 2002 were reviewed. Symptoms and measured laxity were recorded before and after medial canthal tendon repair. The medial canthal tendon was routinely repaired through a cut along the lid margin extending from the punctum medially. This avoids a vertical cut onto the anterior lamella of the eyelid, which is useful if a skin graft is required. Results: Twenty lower eyelid medial canthal tendon repairs were performed on 17 patients. Preoperatively, the lower punctum in all patients was able to be distracted to the medial limbus or further and in 50% of cases, the lower lid punctum was able to be distracted to the pupil midline or further. Postoperatively all patients had reduction of their medial canthal tendon laxity. Postoperatively in 85% of cases the lower punctum was not able to be distracted beyond the medial limbus; however, 15% of cases still had significant residual laxity. Eighty‐five per cent of patients reported improvement in symptoms. Conclusions: This is an effective procedure in the majority of patients with moderate to severe medial canthal tendon laxity; however, residual lower lid laxity persisted in some patients.
Effect of scan repetition on the reproducibility of optic nerve head topographic measurements with the Top SS
Authors: Akar Yusuf , Bozkurt Banu , Irkeç Murat , Orhan Mehmet , Karaağaoglu Ergun 
Published: April 2004

Abstract Purpose: To determine the effect of scan repetition during a single visit for improved reproducibility of optic nerve head topographic measurements. Methods: One randomly selected eye of 20 healthy subjects with no systemic or ocular disease was evaluated. Half of the subjects were under 30 years of age and the other half were older than 60 years. Five independent image series, each consisting of 10 newly recorded consecutive images, were obtained for each subject over a period of 10 weeks with a confocal scanning laser ophthalmoscope, the Top SS. Subjects were divided into two groups according to disc area being either smaller or larger than 2 mm2. Reproducibility of the measurements in three parameters (volume below, half depth area and the average depth) were calculated for each set of scans. The coefficient of variation (standard deviation divided by the mean) was taken as the measure of reproducibility. Repeated measures of analysis of variation and independent sample t‐test were used for statistical analysis. Statistical significance was set as P < 0.05. Results: Both age groups were found to be equally distributed with respect to sex. There were no significant intergroup differences in keratometry, pupil diameter or refractive error. Increasing the scan repetition per visit up to five improved the reproducibility of the measurements. Further increases in scans per visit reduced the reproducibility. Subjects with larger discs and older age were found to have lower coefficients of variation for topographic measurements. Conclusions: Normal subjects should be examined at least three to four times per visit to have significantly improved reliability of measurements of optic nerve head topography. Factors associated with decreased reproducibility included older age, smaller discs, and more than five scans per visit. Sex, refraction and pupil diameter were shown to have no effect on the reproducibility.
Effect of hinged lamellar keratotomy on post‐keratoplasty astigmatism and vision
Authors: Walker Nathan J , Apel Andrew JG 
Published: April 2004

Abstract Purpose: To show that hinged lamellar keratotomy alone affects refraction and vision in post‐keratoplasty eyes. Methods: A retrospective, non‐comparative, interventional case series was conducted on 28 eyes of 26 patients who had two‐stage laser in situ keratomileusis (LASIK) after penetrating keratoplasty. Records were reviewed with respect to the hinged lamellar keratotomy component of the procedure. The interval between keratoplasty and keratotomy was at least 1 year, and the follow‐up period averaged 29 ± 10 days. The Automated Corneal Shaper with nasal hinge was used. In addition to basic empirical astigmatism calculations, the Alpins method of astigmatism analysis was also employed to ensure that the influence of changes in cylinder axis were correctly taken into account when calculating the refractive change. Results: Surgically induced astigmatism from hinged lamellar keratotomy was not statistically significant in this series; however, the range in values (−9.06 to +7.57 D) has potential clinical ramifications. Nearly 70% of cases studied experienced surgically induced astigmatism of at least 2 D. Mean preoperative uncorrected vision was logMAR 1.06 ± 0.41, which improved marginally postoperatively to logMAR 1.03 ± 0.44 (P = 0.36). Best spectacle‐corrected visual acuity averaged logMAR 0.21 ± 0.16 preoperatively, improving to logMAR 0.09 ± 0.15 (range −0.18 to 0.42) postoperatively, which was a statistically significant improvement (P < 0.01). No difference in refractive or visual outcomes was identified when those with keratoconus were compared to those with other underlying corneal disease processes. Conclusion: Although mean surgically induced astigmatism was not statistically significant, hinged lamellar keratotomy caused considerable changes in astigmatism in nearly 70% of post‐keratoplasty eyes studied. This suggests that clinically significant inaccuracies may result if a one‐stage LASIK procedure is performed on such patients. The authors suggest that reassessment of refraction after keratotomy may improve refractive outcomes.
Morphological changes in keratoconus: pathology or pathogenesis
Authors: Sherwin Trevor , Brookes Nigel H 
Published: April 2004

AbstractKeratoconus was first discriminated from other corneal ectatic diseases in 1854. Since that time the morphological characteristics of keratoconic progression have been invaluable in the diagnosis of the condition. The key clinical features used to identify keratoconus have remained essentially the same since the introduction of the slit‐lamp biomicroscope. Only relatively recently has the development of computerized corneal topography revolutionized the diagnosis of early keratoconus. Analysis of peer‐reviewed literature databases revealed a steady chronological increase in pathological research into the progress of keratoconus. This overview describes the recent advances in our understanding of keratoconic pathology and highlights the interactions within the cornea that may be important in the pathogenesis of this condition.
Pseudoexfoliation syndrome: pathological manifestations of relevance to intraocular surgery
Authors: Conway R Max , Schlötzer‐Schrehardt Ursula , Küchle Michael , Naumann Gottfried OH 
Published: April 2004

AbstractPseudoexfoliation syndrome (PEX) is a common ocular condition often associated with the need for intraocular surgery. Although results of cataract and glaucoma filtering surgery in eyes with PEX in the early stages of the disease may be comparable to those in eyes without PEX, in the later stages morbidity is significantly increased due to periocular surgical complications and the outcome is worse. Surgical and postoperative difficulties are often multifactorial and are directly related to the pathological changes of PEX on intraocular structures. Recent years have seen a large increase in the understanding of the effects of PEX on the various ocular tissues. Although the visible areas of the anterior capsule are most obviously involved, this is only a small part of the picture and of least significance. Biomicroscopically invisible changes of the zonules and their attachments are of greatest consequence. There is also distinct, often active, involvement of almost all tissues of the anterior segment of the eye, many of which have important implications for the anterior segment surgeon including iridopathy, iris vasculopathy (including persistent breakdown of the blood−aqueous barrier and anterior segment hypoxia), ciliary body involvement and keratopathy. Trabecular dysfunction is evident by the deposition of PEX material derived from bothin situand extra‐trabecular production as well as protein and melanin deposition. These changes should be kept in mind by all intraocular surgeons as a source of potential difficulties in the perioperative period. Additionally, in light of these changes, patients need to be given realistic expectations regarding the increased risk of complications and more prolonged expected recovery time. In this short review, current reports relating to PEX pathological changes of practical interest to the intraocular surgeon are summarized.
Cooperation and biased competition model can explain attentional filtering in the prefrontal cortex
Authors: Szabo Miruna , Almeida Rita , Deco Gustavo , Stetter Martin 
Published: April 2004

AbstractRecent neurophysiological experimental results suggest that the prefrontal cortex plays an important role in filtering out unattended visual inputs. Here we propose a neurodynamical computational model of a part of the prefrontal cortex to account for the neural mechanisms defining this attentional filtering effect. Similar models have been employed to explain experimental results obtained during the performance of attention and working memory tasks. In this previous work the principle of biased competition was shown to successfully account for the experimental data. To model the attentional filtering effect, the biased competition model was extended to enable cooperation between stimulus selective neurons. We show that, in a biological relevant minimal model, competition and cooperation between the neurons are sufficient conditions for reproducing the attentional effect. Furthermore, a characterization of the parameter regime where the cooperation effect is observed is presented. Finally, we also reveal parameter regimes where the network has different modes of operation: selective working memory, attentional filtering, pure competition and noncompetitive amplification.
Repositioning of charged I–II loop amino acid residues within the electric field by β subunit as a novel working hypothesis for the control of fast P/Q calcium channel inactivation
Authors: Sandoz Guillaume , Lopez‐Gonzalez Ignacio , Stamboulian Séverine , Weiss Norbert , Arnoult Christophe , De Waard Michel 
Published: April 2004

AbstractWe have investigated the contribution of the Cavβ subunits to the process of inactivation dependent of the I–II loop of Cavα2.1. Two amino acid residues located in the alpha1 interaction domain (AID) of the I–II loop of Cavα2.1 (Arg387 and Glu388) have been directly implicated in voltage‐dependent inactivation of this channel. Various point mutations of these residues disrupt the interaction between the I–II loop and the III–IV loop, and thereby modify the inactivation properties of the channel by accelerating its kinetics and shifting the steady‐state inactivation curve towards hyperpolarized potentials. A similar disruption is produced by Cavβ4 subunit association with the I–II loop. Moreover, in the presence of Cavβ4 subunit, introducing negatively charged residues at positions 387 or 388 slows inactivation kinetics down, whereas introducing positive charges has the opposite effect. The shift of the steady‐state inactivation curve is also amino acid charge‐dependent. In contrast, mutation of Arg387 or Glu388 does not alter the differential regulation of the different Cavβ isoforms on inactivation. These results suggest that the expression of Cavβ4 alters the contribution of charged residues at positions 387 and 388 to inactivation. We discuss these results with regard to the actual hypotheses on the mechanisms of calcium channel inactivation. We introduce the working concept that Cavβ‐subunits produce a conformational repositioning of charged AID residues within the electric field.
Transcriptional response to circumscribed cortical brain ischemia: spatiotemporal patterns in ischemic vs. remote non‐ischemic cortex
Authors: Küry Patrick , Schroeter Michael , Jander Sebastian 
Published: April 2004

AbstractFocal brain infarcts are surrounded by extended perilesional zones that comprise the partially ischemic penumbra but also completely non‐ischemic cortex of the remote ipsilateral hemisphere. To delineate the impact of lesion‐associated vs. remote processes on transcriptional programming after focal ischemia, we used cDNA array analysis, quantitative real‐time polymerase chain reaction and immunohistochemistry in the photothrombosis model of circumscribed cortical ischemia in rats. At an early stage of 4 h after ischemia, gene induction occurred to a similar extent in the ischemic infarct and remote non‐ischemic cortex of the ipsilateral hemisphere. Among the genes induced in non‐ischemic cortex we found the NGF‐inducible genes PC3, VGF and Arc, the transcriptional regulators IκB‐α and Stat3, and the β‐chemokine MIP‐1α (CCL3). At 3 days, the spatial pattern of gene expression had changed dramatically with brain fatty acid‐binding protein as the only gene significantly induced in non‐ischemic ipsilateral cortex. In contrast, numerous genes were exclusively regulated at the lesion site, comprising genes involved in cell cycle regulation, proteolysis, apoptosis, lipid homeostasis and anti‐inflammatory counter‐regulation. Cortical spreading depression was identified as the main mechanism underlying gene induction in remote non‐ischemic cortex. Our data demonstrate a dynamic spatiotemporal pattern of gene induction, which may contribute to delayed progression of damage or, alternatively, mediate neuroprotection, tissue remodeling and functional compensation.
The interplay between oxidative stress and brain‐derived neurotrophic factor modulates the outcome of a saturated fat diet on synaptic plasticity and cognition
Authors: Wu Aiguo , Ying Zhe , Gomez‐Pinilla Fernando 
Published: April 2004

AbstractA diet high in saturated fat (HF) decreases levels of brain‐derived neurotrophic factor (BDNF), to the extent that compromises neuroplasticity and cognitive function, and aggravates the outcome of brain insult. By using the antioxidant power of vitamin E, we performed studies to determine the role of oxidative stress as a mediator for the effects of BDNF on synaptic plasticity and cognition caused by consumption of the HF diet. Male adult rats were maintained on a HF diet for 2 months with or without 500 IU/kg of vitamin E. Supplementation of the HF diet with vitamin E dramatically reduced oxidative damage, normalized levels of BDNF, synapsin I and cyclic AMP‐response element‐binding protein (CREB), caused by the consumption of the HF diet. In addition, vitamin E supplementation preserved the process of activation of synapsin I and CREB, and reversed the HF‐impaired cognitive function. It is known that BDNF facilitates the synapse by modulating synapsin I and CREB, which have been implicated in synaptic plasticity associated to learning and memory. These results show that oxidative stress can interact with the BDNF system to modulate synaptic plasticity and cognitive function. Therefore, studies appear to reveal a mechanism by which events classically related to the maintenance of energy balance of the cell, such as oxidative stress, can interact with molecular events that modulate neuronal and behavioural plasticity.
Differences between brain structures in nuclear translocation and DNA binding of the glucocorticoid receptor during stress and the circadian cycle
Authors: Kitchener Pierre , Di Blasi Francesco , Borrelli Emiliana , Piazza Pier Vincenzo 
Published: April 2004

AbstractGlucocorticoid receptors (GRs) are transcription factors that, upon activation by glucocorticoids, translocate to the cell nucleus, and bind to specific response elements (GREs) in the promoter region of target genes. We analysed stress‐ and circadian‐induced changes in nuclear translocation and GRE binding of GRs in the hippocampus and the prefrontal cortex of the rat brain. Nuclear translocation and binding to GRE were measured in nuclear extracts by Western blot and gel shift, respectively. When glucocorticoid levels were low, as during the light period of the circadian cycle, nuclear GRs and GRE binding were almost undetectable. However, the increase in glucocorticoid levels observed during the dark phase of the circadian cycle or after stress induced a massive nuclear translocation of GRs and GRE binding. These effects were corticosterone‐dependent because they were suppressed by adrenalectomy and restored by the injection of corticosterone. Furthermore, GR translocation and GRE binding were of higher amplitude or lasted longer in the hippocampus than in the prefrontal cortex. By contrast, extracellular levels of glucocorticoids, measured by microdialysis in freely moving animals, were identical in the two structures. These results suggest that specific intracellular regulations of GR activity contribute to differentiate the effects of glucocorticoids in different regions of the brain.