bluuebunny/crossref_metadata_2025_split huggingface dataset:
Choroidal thickness measurement in highly myopic eyes using SD ‐ OCT
Authors: EL MATRI L , BOULADI M , CHEBIL A , KORT F , TRIKI M , LIMAIEM R , MGHAIETH F 
Published: November 2010

Abstract Purpose to measure macular choroidal thickness (CT) using spectral domain optical coherence tomography (OCT) and to investigate the correlation between CT and age, degree of myopia, and a history of macular choroidal neovascularization (CNV). Methods a cross sectional study was performed in 191 eyes of 106 patients with spherical equivalent (SE) refractive error of 6 diopters (D) or more, between early January 2010 and early June 2010. The choroid was imaged using the spectral domain OCT (OCT TOPCON 2000) by changing the reference position from the vitreous to the choroid without inverting the image. CT was measured from the outer border of the hyperreflective line corresponding to the retinal pigment epithelium (RPE) to the inner scleral border. Results the mean age of the 106 patients was 47,9 years ( ± 14,89 years; range, 18 to 81 years), 32 were men and 74 were women, the mean SE refractive error was 13,73 D (±5,74 D), and the mean subfoveal CT was 100,42 µm (±60,15µm; range, 23‐278). CT was correlated negatively with age (p= 0,01), and refractive error (p=0,01). Fourty eyes had a history of CNV, the mean CT was 52,02 ± 17,65 µm, and this was significantly thinner than the subgroup without CNV (p<0,10‐6 ). Conclusion in highly myopic eyes, the choroid is thin and undergoes further attenuation with increasing age and increasing myopia. In addition, these findings suggest that the choroid may play a role in the pathogenesis of choroidal neovascularization.
Longitudinal visual outcome 10 years after cataract surgery
Authors: MöNESTAM EI , LUNDQVIST B 
Published: November 2010

Abstract Purpose This prospective, population‐based cohort study reports the longitudinal visual functional outcome of cataract surgery on a long‐term basis. Methods 810 participants underwent cataract surgery during a 1‐year period. Before surgery, a few months after surgery, and 5 and 10 years after surgery, age and comorbidity were recorded, and BCVA was measured. At all occasions the patients also answered the same visual functional questionnaire (VF‐14). Ten years after surgery 335 (85% of survivors) participated with the questionnaire of whom 289 (73% of survivors) were re‐examined. Results Ten years after surgery 76% of the patients examined had a BCVA of 20/40 or better, and 65% had a BCVA of 20/30 or better, which is a decline from 88% and 84% after surgery, respectively. Regarding each operated eye, 50% had unchanged or better VA, and an additional 19% had only lost less than 0.1 logMAR units, compared with postoperatively. Forty‐six patients (16%) had a decline in BCVA of more than 0.3 logMar units. The median VF‐14‐total score was 100 after surgery, declining to 96.7 5 years after surgery, and to 96.4 10 years after surgery. Ten years after surgery 49% of the patients had unchanged or better subjective visual function and 77% had less than 10 points in decline compared with preoperatively. Nine percent (31 of 335 patients) had a worsening of VF‐14 total score of 40 points or more. In this group age‐related macular degeneration (ARM) was the most common cause followed by bullous keratopathy. Conclusion Longitudinal follow‐up of this older population confirms that subjective and objective visual function 10 years after cataract surgery remains stable in most surviving patients. Cataract surgery offers good long‐term visual rehabilitation for cataract.
Origin of the ERG omitted stimulus response: evidence from patients with congenital stationary night blindness
Authors: ANASTASAKIS A , MCANANY JJ , ALEXANDER KR , FISHMAN GA 
Published: November 2010

Abstract Purpose Purpose: The omitted stimulus response (OSR) of the full‐field flicker ERG is an additional response component that follows stimulus termination. It has been attributed to a resonant oscillation in depolarizing (ON) bipolar cells. We evaluated this proposal by determining whether an OSR is present in the flicker ERG of patients with the complete type of congenital stationary night blindness (CSNB1) and presumed ON‐pathway dysfunction. Methods Methods: Subjects included two patients with ERG findings typical of CSNB1 and 11 normally sighted individuals. Molecular genetic analysis confirmed a mutation in the NYX gene (Trp273Ter) of patient 1 and in the GRM6 gene (Arg621Ter) of patient 2. Monocular ERGs were recorded in response to full‐field sinusoidal flicker trains, ranging from 6.33 to 100 Hz, presented against a rod saturating background. The amplitude and relative delay of additional ERG responses following the offset of the flicker trains were analyzed. Results Results: Across the frequency range of 39 to 63 Hz, the number of ERG responses exceeded the number of stimulus cycles for all control subjects. The delay between the additional response component and the last stimulus cycle was frequency dependent, consistent with an OSR. In the two patients with CSNB1, however, the number of ERG responses equaled the number of stimulus cycles at all frequencies. Conclusion Conclusion: The absence of an OSR in these two CSNB1 patients supports the hypothesis that ON bipolar cells play a key role in the generation of this response.
Perceptual threshold and neuronal excitability as long‐term safety evaluation in retinal implants
Authors: VELIKAY‐PAREL M , IVASTINOVIC D , GEORGI T , HORNIG R 
Published: November 2010

Abstract Purpose Despite the recent progress of retinal implants the effects of continuing stimulation still remains an open issue. Sofar the established safety limits are based on laboratory findings and clinical observations.This study examined the changes of perceptual threshold over time and its relation to longterm stimulation. The goal of the study was to establish stimulus induced depression of neuronal excitability (SIDNE) measurements as a method to gain further insight on the safety profile of epiretinal implants. Methods As part of a clinical trial a prototype of an epiretinal implant ( IMI Intelligent medical implant) with 61 active platinum electrodes was implanted in a retinitis pigmentosa (RP) patient. The threshold was defined as the level of stimulation intensity at which the patient had a visual perception in a defined probability of 50% using the Best‐PEST method. SIDNE is measured by comparing the thresholds of two electrodes obtained at the beginning and at the end of a stimulation session. One electrode is actively used during the stimulation, the other remains passive. The stimulation is regarded as safe when the threshold raise of active electrodes is not significantly higher than of the inactive electrode. Results The threshold remained stable over the observation period. The threshold raise of the active electrodes never exceeded that of the inactive electrode. Conclusion SIDNE measurement is feasible in epiretinal implants. After prolonged stimulation the thresholds may increase by more than 16 % due to the patients fading concentration, however the stimulation was performed within the safety limits.
Seeing with subretinal electronic implants in blind volunteers requires direct link of image receiver to eye movement
Authors: ZRENNER E 
Published: November 2010

Abstract Purpose To compare subretinal electrode‐generated percepts elicited by stationary stimulation with those elicited by light‐sensitive subretinal arrays during patient initiated natural eye movements. Methods The Tuebingen subretinal implant consists of two arrays: a) 4 x 4 electrode field controlled externally for direct electrical stimulation (DS array), b) a light sensitive “CHIP” (3 x 3 x 0.1mm) with 1500 photodiodes, amplifiers and electrodes. Results Patterns presented via DS electrodes repeatedly to the same retinal position disappear after seconds. With the light sensitive subretinal CHIP, however, objects like grating patterns, tableware or letters can be perceived continuously (repeated at 7 Hz for 1 ms. Clearly objects scanned with natural eye movements via light sensitive retinal CHIP activate a range of adjacent pixels on the CHIP, i.e. eye movements and microsaccades continuously shift the “electrical image” on the retina, thus preventing mechanisms of image fading Conclusion The results clearly support the feasibility of light sensitive subretinal multi‐electrode devices for restoration of useful visual percepts in blind patients. Continuous stimulation of fixed electrodes can provide only quickly fading percepts (similar to the Troxler effect). In contrast, percepts of images constantly moving across the subretinal light‐sensitive chip – due to saccadic and fixational eye movement ‐‐ remain visible without measurable temporal limitation. We conclude that real‐time information of eye movements (an efference copy) is required by the brain to generate stable percepts. This is only available if the light sensitive part of the implant moves exactly with the eye, as presently realized only in the subretinal Tuebingen CHIP
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Specific deficits in visual electrophysiology without retinal cellular apoptosis in a mouse model of dominant optic atrophy
Authors: BARNARD AR , PIECHOTA M , SEKARAN S , POWELL K , MACLAREN RE , DAVIES V , VOTRUBA M 
Published: November 2010

Abstract Purpose Autosomal dominant optic atrophy (ADOA) due to mutations in OPA1 is a slowly progressive optic neuropathy. OPA1 is ubiquitously expressed and plays a key role in mitochondrial fusion. Heterozygous Opa1 mutant mice (B6;C3‐Opa1Q285STOP), with previously reported visual defects and optic nerve changes, were assessed for retinal sequelae. Methods ERGs and VEPs were recorded in 12 month old B6;C3‐Opa1Q285STOP mice (n=4) and age/sex matched wildtype littermate controls. Full scotopic and photopic intensity series were recorded in response to brief (4 ms) single flash stimuli delivered in a ganzfeld dome. End‐organ evidence for apoptosis was explored on TUNEL stained retinal sections. Results Quantification of the major ERG components (a‐wave and b‐wave) confirmed no detectable difference in the amplitude or implicit time of scotopic ERGs across the full intensity range tested. This was also true for the VEP components. Quantification of the photopic ERG responses revealed a significant reduction in the PhNR amplitude in Opa1+/‐ animals relative to wildtypes at the brightest intensity tested. The photopic VEP was also abnormal in mutant mice. There was no increased apoptosis in retinal sections from mutant animals. Conclusion Opa1+/‐ mice display a functional deficit on electrophysiology that is indicative of specific ganglion cell dysfunction. Despite a 50% reduction in Opa1 protein there does not appear to be a significant increase in apoptosis in the retina. This suggests that the protein truncating mutation in this model may lead to RGC dysfunction without triggering RGC death.
How do we recognize objects? An intracranial study
Authors: BERTRAND JA , ROBERT M , NGUYEN DK , BOUTHILLIER A , LASSONDE M , LEPORE F 
Published: November 2010

Abstract Purpose How the brain recognizes visual stimuli has been extensively studied using scalp surface electrodes and magnetic resonance imaging. Complex visual stimuli such as objects and faces have been shown to strongly activate the ventral visual stream in humans. The link between this pathway of activation (bottom‐up processes) and the memory (top‐down processes) still has to be described. Methods In the present experiment, intracranial electroencephalography was carried out in epileptic patients implanted with subdural electrodes to localize the epileptic focus so as to directly assess brain activations evoked by visual stimuli. Fragmented pictures of objects with eight levels of coherence were used whereby at level 1 the stimulus was unrecognizable and at level 8, it constituted the complete picture. We measured the evoked potentials at four levels of recognition: threshold (T‐0), two levels before threshold (T‐1 and T‐2) and one post threshold (T+1). Results Activations were found in V1, V2, LOC, orbito‐frontal cortex (OF) and hippocampus. In V1 and V2, the early visual response suggested a higher level of treatment when trying to integrate the information to recognize the stimulus. The higher order structures, such as LOC and OF, gave their largest responses mainly at longer latencies. Conclusion This intracranial study permits precise localization coupled with high temporal resolution, which allows for a better understanding of the different mechanisms involved in a fast and accurate visual recognition of objects.
Cataract surgery in ambulatory surgery unit: our experience in 14 years
Authors: PEREZ GARCIA D , IBANEZ ALPERTE J , CRISTOBAL BESCOS JA , MINGUEZ MURO E , JIMENEZ A , JIMENEZ DEL RIO B , CASAS P , RAMIRO MILLAN P , CRUZ N 
Published: November 2010

Abstract Purpose To evaluate the outcomes of cataract surgery in the Ambulatory Surgery Unit in our hospital from 1995 to 2009. Methods Retrospective and descriptive study including 5087 cataract surgeries performed in our hospital between 1995 and 2009. We have analysed several indicators(substitution, suspension),variables(gender, age, anesthesia, surgical technique, morbidity, pre‐and postoperative medication required as the degree of patient satisfaction after passage through the unit)and complications after surgery. The data analysis program used was StatView. Results During the period studied, cataract surgery was the most common surgery in the unit, representing a 30.4% of the total, and the most common eye surgery (77.8%). The 54.94% of the patients were women, average age 73.11 years. Retrobulbar anesthesia was the most common with 74.03% of the surgeries, and the the preferred surgical technique was phacoemulsification and intraocular lens implantation(91.74%). Twenty one patients had severe complications(arterial hypertension, nausea, vomiting, vasovagal syncope...) that required admission to hospital. Conclusion The model of Ambulatory Surgery in cataract surgery has proved, through their results in time and in properly selected patients, safe, efficient and effective, establishing as a consolidated unit in ophthalmologic patients.
How does scleral buckling affect the anterior segment of the eye?
Authors: ASCASO FJ , RUIZ DE GOPEGUI E , DEL BUEY MA , LAVILLA L , CRISTOBAL BESCOS JA 
Published: November 2010

Abstract Purpose To describe the modifications produced in the anterior segment of the eye after placing an encircling scleral buckling (SB) in terms of corneal morphology, biomechanics and intraocular pressure. Methods A prospective study of 15 eyes with rhegmatogenous retinal detachment who underwent pars plana vitrectomy combined with a scleral buckle (PPV/SB), and 12 eyes with vitreous hemorrhage treated with PPV alone. We measured preoperatively and 1‐month after surgery the corneal biomechanical properties using the Ocular Response Analyzer (ORA), including corneal hysteresis (CH), corneal resistance factor (CRF), intraocular pressure (IOPg), and corneal compensated IOP (IOPcc). Moreover, we defined the corneal morphology by 4 parameters provided by the topographer Orbscan IIz: mean corneal power (dioptres), standard deviation, thinnest point (µm), and anterior chamber depth (ACD) (mm). Results Mean CH values were significantly diminished following PPV/SB (p=0.003). We found no significant changes in CRF. IOPg and IOPcc mean values were significantly increased only in the PPV/SB group (p=0.019 and p=0.010, respectively) but not in PPV group (p=0.715 and p=0.273, respectively). In PPV/SB group, IOPcc mean values were significantly higher than IOPg before (p=0.001) and after surgery (p=0.003), but not in the other group. None of the morphological parameters were modified after surgery in any of the two study groups (p>0.05) Conclusion Anterior segment morphology was not modified after placing a SB. Corneal biomechanical properties showed a reduction in CH, probably due to a vascular constriction and reduction of the eye compliance. PPV might be considered a less invasive approach for the repair of noncomplex retinal detachments than PPV/SB.
Acute mechanical effect of riboflavin corneal cross‐linking
Authors: PENNOS A , KARYOTAKIS N , KONTADAKIS G , PENTARI IG , PALLIKARIS IG , GINIS HS 
Published: November 2010

Abstract Purpose To study the acute mechanical effect of corneal cross‐linking in vitro. Methods Twenty porcine eyes were harvested from a local abattoire. The epithelium was removed using a rotating brush and corneal buttons having diameter of 8 mm were excised using a Barron’s PKP trephine. The buttons were left immersed for four hours in Dextran solution (20%W/V) in order to regulate their hydration. The buttons were immersed in riboflafin 0.1% in dextran 20% and separated in two groups (10 buttons each) where one group was irradiated for 30 minutes with UV light while the other group was not irradiated and served as control. After treatment mechanical measurements were performed by means of a purposely‐developed device featuring a stepping motor and a load cell. The motor shaft has a spherical tip that compresses the corneal button against a flat surface mounted on the load cell. The slope of force versus normalized deformation was recorded for each specimen. Results The control group had an average slope of 3.55 (± 1.81) while the irradiated group had 4.47 (±1.80). This difference was not statistically significant. (p=0.27) Conclusion This compressibility test did not reveal statistically significant changes between the two groups immediately after UV corneal cross‐linking. It remains to be elucidated whether different tests (e.g. elongation) may yield different results.
Three cases of reverse pupillary block after suturing of intraocular lens to the ciliary sulcus in avitreous eyes
Authors: KIMURA M , TSUDA M , MATSUYAMA K , ANDO A , NISHIMURA T , TAKAHASHI K 
Published: November 2010

Abstract Purpose To report three cases of reverse pupillary block after suture of intraocular lens(IOL) to the ciliary sulcus in avitreous eyes. Methods Visual impairment occurred in three eyes of three patients with past surgical history of vitrectomy and suture of IOL to the ciliary sulcus. Their findings of anterior segment showed deep anterior chamber (6000μm~4330μm) with concavity of the intermediate and peripheral iris, compression bonding of the pupil and IOL, and pigmentation of the trabecular meshwork. The diagnosis of a reverse pupillary block was made by opthalmological examinations and additional tests, e.g., ultrasonography and Pentacam®. In all eyes, laser iridotomy(LI) was performed in the superior peripheral iris to eliminate reverse pupillary block. Results As a result, reverse pupillary block was eliminated and the depth of anterior chamber returned to normal (4018μm~3700μm), furthermore, concavity of the iris and compression bonding of the pupil and IOL were disappeared in all eyes. Conclusion In the eyes with past surgical history of vitrectomy and suture of IOL to the ciliary sulcus, reverse pupillary block might occur and LI can be effective.
Are visual evoked potentials and pattern ERG useful in neuro‐ophthalmology?
Authors: HOLDER GE 
Published: November 2010

Abstract Purpose To describe the roles of VEP and PERG in clinical neuroophthalmology. Methods Case based examples. Results Objective visual system testing with electrophysiology allows the distinction between optic nerve and macular dysfunction, often difficult in clinical practice. Examples will be shown of the types of VEP abnormality that can occur in different disorders of optic nerve function. PERG should also be performed in the patient with visual symptoms; if the PERG suggests macular dysfunction, full‐field ERG is indicated in order to determine whether that macular dysfunction is part of a generalised retinal process or is dysfunction localised to the macula. Electrophysiology further allows the diagnosis of non‐organic visual loss and the quantification of visual system dysfunction. Conclusion The objective functional assessment with electrophysiology is an important part of the diagnostic armamentarium available to neuroophthalmologists.
Tobacco‐alcohol amblyopia: does it really exist?
Authors: GRZYBOWSKI A 
Published: November 2010

Abstract Purpose Each textbook on ophthalmology in the 19th and the 20th centuries included a description of “tobacco‐alcohol amblyopia”. In the last 200 years several thousand cases of “tobacco‐alcohol amblyopia” were described, but the occurrence of the disorder has considerably decreased in modern times. Methods Review of the literature and described cases of the entity. Results By the end of the 20th century, a paradox had become apparent: the population of tobacco and alcohol users in some areas of the world continued to be very high, but there was a marked decrease in the incidence of the disease. Some believe that the disease never existed, some argue that it was a mismatch – or / and overdiagnosed. Conclusion The presentation is going to cover the present status of knowledge about “tobacco‐alcohol amblyopia” and to finally give the answer whether such entity exists.
What next when the biopsy is negative in suspected giant cell arteritis (GCA)?
Authors: BOSCHI A 
Published: November 2010

Abstract Purpose To present and discuss the approach of GCA when temporal artery biopsy (TAB) is negative. Recommendations for reducing the rate of negative TAB Methods GCA is the commonest vasculitis. Visual loss occurs in up to one‐fifth of patients, which may be preventable by prompt recognition and treatment. Features predictive of ischaemic neuro‐ophthalmic complications are: jaw claudication, diplopia, and temporal artery abnormalities on physical examination. These manifestations and particularly blindness and jaw claudication seems to be more commonly associated with positive TAB. Results Despite visual symptoms TAB may result negative. Rate of negative TAB varies from 7% to 40% in pat suspected of GCA. TAB should be done 2 to 6 weeks after commencement of treatment, and at least 1 cm. Contralateral biopsy is controversies, usually it increases the rate of GCA diagnosis of only 5%. Conclusion If TAB is still however negative, but clinical suspicion high or Ultra‐Sound suggests GCA or complications typical of GCA, like anterior ischemic optic neuropathy, patient should be treat as biopsy‐positive GCA patient. If the clinical suspicion is low, features considered atypical or alternative explanations available, rapid glucocorticoid therapy should be tapered.
Sixth nerve palsy: who needs a workup, who needs a scan?
Authors: PURVIN V 
Published: November 2010

Abstract Purpose To aid the clinician in the management of patients with sixth nerve palsy. Methods The yield of various diagnostic for sixth nerve and other cranial nerve palsies will be reviewed. Attention will focus on risk factors that predict a positive result on diagnostic testing, particularly neuroimaging. Results Most patients can be assigned a relative risk of harboring an underlying disease as the cause of their sixth nerve palsy but some will be missed. In most cases, a delayed diagnosis does not alter the outcome. Conclusion The decision whether to image a patient with a sixth nerve palsy remains controversial and must be individualized.