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1.
IEEE Trans Biomed Circuits Syst ; 15(5): 860-876, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34543202

RESUMO

This paper presents a 1024-channel neural read-out integrated circuit (ROIC) for solution-gated GFET sensing probes in massive µECoG brain mapping. The proposed time-domain multiplexing of GFET-only arrays enables low-cost and scalable hybrid headstages. Low-power CMOS circuits are presented for the GFET analog frontend, including a CDS mechanism to improve preamplifier noise figures and 10-bit 10-kS/s A/D conversion. The 1024-channel ROIC has been fabricated in a standard 1.8-V 0.18- µm CMOS technology with 0.012 mm 2 and 36 µ W per channel. An automated methodology for the in-situ calibration of each GFET sensor is also proposed. Experimental ROIC tests are reported using a custom FPGA-based µECoG headstage with 16×32 and 32×32 GFET probes in saline solution and agar substrate. Compared to state-of-art neural ROICs, this work achieves the largest scalability in hybrid platforms and it allows the recording of infra-slow neural signals.


Assuntos
Mapeamento Encefálico , Calibragem
2.
Transl Vis Sci Technol ; 4(2): 14, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25938002

RESUMO

PURPOSE: To analyze static visual field sensitivity with topographic models of the hill of vision (HOV), and to characterize several visual function indices derived from the HOV volume. METHODS: A software application, Visual Field Modeling and Analysis (VFMA), was developed for static perimetry data visualization and analysis. Three-dimensional HOV models were generated for 16 healthy subjects and 82 retinitis pigmentosa patients. Volumetric visual function indices, which are measures of quantity and comparable regardless of perimeter test pattern, were investigated. Cross-validation, reliability, and cross-sectional analyses were performed to assess this methodology and compare the volumetric indices to conventional mean sensitivity and mean deviation. Floor effects were evaluated by computer simulation. RESULTS: Cross-validation yielded an overall R2 of 0.68 and index of agreement of 0.89, which were consistent among subject groups, indicating good accuracy. Volumetric and conventional indices were comparable in terms of test-retest variability and discriminability among subject groups. Simulated floor effects did not negatively impact the repeatability of any index, but large floor changes altered the discriminability for regional volumetric indices. CONCLUSIONS: VFMA is an effective tool for clinical and research analyses of static perimetry data. Topographic models of the HOV aid the visualization of field defects, and topographically derived indices quantify the magnitude and extent of visual field sensitivity. TRANSLATIONAL RELEVANCE: VFMA assists with the interpretation of visual field data from any perimetric device and any test location pattern. Topographic models and volumetric indices are suitable for diagnosis, monitoring of field loss, patient counseling, and endpoints in therapeutic trials.

3.
Exp Eye Res ; 105: 70-8, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23099334

RESUMO

Previously we developed a mathematical model for describing the retinal nerve fiber bundle trajectories in the superior-temporal and inferior-temporal regions of the human retina, based on traced trajectories extracted from fundus photographs. Aims of the current study were to (i) validate the existing model, (ii) expand the model to the entire retina and (iii) determine the influence of refraction, optic disc size and optic disc position on the trajectories. A new set of fundus photographs was collected comprising 28 eyes of 28 subjects. From these 28 photographs, 625 trajectories were extracted. Trajectories in the temporal region of the retina were compared to the existing model. In this region, 347 of 399 trajectories (87%) were within the 95% central range of the existing model. The model was extended to the nasal region. With this extension, the model can now be applied to the entire retina that corresponds to the visual field as tested with standard automated perimetry (up to approximately 30° eccentricity). There was an asymmetry between the superior and inferior hemifields and a considerable location-specific inter-subject variability. In the nasal region, we found two "singularities", located roughly at the one and five o'clock positions for the right optic disc. Here, trajectories from relatively widespread areas of the retina converge. Associations between individual deviations from the model and refraction, optic disc size and optic disc position were studied with multiple linear regression. Refraction (P = 0.021) and possibly optic disc inclination (P = 0.09) influenced the trajectories in the superior-temporal region.


Assuntos
Axônios , Modelos Teóricos , Disco Óptico/anatomia & histologia , Nervo Óptico/anatomia & histologia , Refração Ocular/fisiologia , Células Ganglionares da Retina/citologia , Adulto , Humanos , Tamanho do Órgão , Estudos Retrospectivos , Campos Visuais/fisiologia
4.
Invest Ophthalmol Vis Sci ; 51(11): 5685-9, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20538998

RESUMO

PURPOSE: To assess the spatial distribution of glaucomatous visual field defects (VFDs) obtained with regionally condensed stimulus arrangements. METHODS: Sixty-three eyes of 63 glaucoma subjects were examined with threshold-estimating automated static perimetry (full threshold 4-2-1 dB strategy with at least three reversals) on an automatic campimeter or a full-field perimeter. Stimuli were added by the examiner to regionally enhance spatial resolution in regions that were suspicious for a glaucomatous VFD. These regions were characterized by contiguous local VFDs, attributable to the retinal nerve fiber bundle course according to the impression of the examiner. The added stimulus locations were subsets of a predefined, dense perimetric grid. All VFD locations with P < 0.05 (total deviation plots) were assessed by superimposing the visual field records of all participants. RESULTS: Glaucomatous VFD loss occurred more frequently in the upper than in the lower hemifield, with a typical retinal nerve fiber-related pattern and a preference of the nasal step region. More than 50% of the eyes with predominantly mild to moderate glaucomatous field loss showed defective locations in the immediate superior paracentral region within an eccentricity of 3°. CONCLUSIONS: Conventional thresholding white-on-white perimetry with regionally enhanced spatial resolution reveals that glaucomatous visual field loss affects the immediate paracentral area, especially the upper hemifield, in many eyes with only mild to moderate glaucomatous visual field loss. Detailed knowledge about the spatial pattern and the local frequency distribution of glaucomatous VFDs is an essential prerequisite for creating regionally condensed stimulus arrangements for adequate detection and follow-up of functional glaucomatous damage.


Assuntos
Glaucoma de Ângulo Aberto/diagnóstico , Transtornos da Visão/diagnóstico , Campos Visuais , Adulto , Idoso , Feminino , Glaucoma de Ângulo Aberto/classificação , Glaucoma de Ângulo Aberto/fisiopatologia , Humanos , Pressão Intraocular , Masculino , Pessoa de Meia-Idade , Limiar Sensorial , Transtornos da Visão/fisiopatologia , Acuidade Visual , Testes de Campo Visual
5.
Eur J Ophthalmol ; 20(1): 149-57, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19882509

RESUMO

PURPOSE: To compare the results of advanced visual field defects (VFD) measured with the conventional reference perimeter Octopus 101 (O-101) and the new portable Tübingen Mobile Campimeter (TMC). METHODS: Thirty-seven subjects (18 to 75 years), 13 with advanced arcuate scotomas, 12 with VFD respecting vertical meridians, 6 with concentric constriction and 6 healthy controls were included. First examination was with O-101: grid 30 degrees -NO, 192 stimuli, 10 cd/m(2) background luminance, stimulus size: Goldmann III (26'); second examination was with TMC: 84 stimuli (subset of grid 30 degrees -NO), stimulus size 34', stimulus luminance 320-370 cd/m(2), background luminance 8-20 cd/m(2). Pointwise accuracy (proportion of concordant locations), sensitivity, and specificity were estimated into 95% confidence intervals (CI) by averaging individual logits. Examination durations were compared. RESULTS: TMC results are highly concordant with O-101 results for all defect classes. For the entire sample, the percentage of discordant points (perceived with TMC but not with O-101) among all discordant points was 35% (CI: 30% to 40%). Analyzed by VFD pattern, accuracy was highest in healthy controls scotomas (97.9%; CI: 97% to 98.5%) and lowest in arcuate scotomas (80.6 %; CI: 77.3% to 83.5%). Sensitivity was highest in concentric constriction (94.5%; CI: 82.9% to 98.4%) and lowest in healthy controls (59.1%; CI: 26.3% to 85.3%). Specificity was highest in healthy controls (98.1%; CI: 96.6% to 98.9%) and lowest in concentric constriction (77.4%; CI: 62.1% to 87.7%). Mean examination time was 4.6 minutes (TMC) and 9.8 minutes (O-101). CONCLUSIONS: The results indicate that the TMC is a feasible device for detection of VFD.


Assuntos
Escotoma/diagnóstico , Testes de Campo Visual/instrumentação , Campos Visuais , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Testes de Campo Visual/métodos , Adulto Jovem
6.
Acta Ophthalmol ; 88(1): 65-9, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19094165

RESUMO

PURPOSE: This study aimed to evaluate reaction time (RT) in patients with advanced visual field (VF) loss using semi-automated kinetic perimetry (SKP). METHODS: Seventy-eight patients with advanced VF loss caused by glaucoma (31) or retinitis pigmentosa (19), homonymous VF loss caused by post-chiasmal lesions (18) and unilateral anterior ischaemic optic neuropathy (AION) (10) were examined with SKP (Octopus 101 perimeter). One eye in each patient was enrolled. Additionally, VFs in the 10 healthy fellow eyes of the patients with AION were compared with those in the 10 affected eyes. Reaction time was assessed during the SKP session by presenting kinetic stimuli (III4e) with constant angular velocities of 3 degrees /second moving linearly along so-called 'RT vectors' at four different locations inside the III4e isoptre. Each stimulus presentation was repeated four times in randomized order. RESULTS: The geometric mean RT was 794 ms (95% reference interval [RI] 391-1615 ms) in patients with glaucoma, 702 ms (95% RI 306-1608 ms) in patients with retinitis pigmentosa and 675 ms (95% RI 312-1460 ms) in patients with hemianopia. Increases in RT for every 1 degree of eccentricity were 1%, 0.9% and 0.4%, respectively. The geometric mean RT in the 10 patients with unilateral optic neuropathy was 644 ms in affected eyes and 435 ms in unaffected eyes, reflecting an increase of 51% (95% confidence interval 42-62%). CONCLUSIONS: We found substantial inter-subject variability in RT in patients with advanced VF loss. It is possible to correct the position of the isoptres by assessing individual RT. There were no relevant differences in RT between the disease groups. Reaction time increases with eccentricity. In monocular disease (AION), RT is prolonged, compared with in healthy fellow eyes. However, in clinical routine the RT-related displacement of isoptres is negligible in the vast majority of cases.


Assuntos
Transtornos da Visão/diagnóstico , Transtornos da Visão/fisiopatologia , Testes de Campo Visual/métodos , Campos Visuais , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Automação , Feminino , Glaucoma/complicações , Hemianopsia/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Neuropatia Óptica Isquêmica/complicações , Tempo de Reação , Retinose Pigmentar/complicações , Índice de Gravidade de Doença , Transtornos da Visão/etiologia , Adulto Jovem
7.
Graefes Arch Clin Exp Ophthalmol ; 247(12): 1659-69, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19639334

RESUMO

PURPOSE: The goal of this work was to (i) determine patterns of progression in glaucomatous visual field loss, (ii) compare the detection rate of progression between locally condensed stimulus arrangements and conventional 6 degrees x 6 degrees grid, and (iii) assess the individual frequency distribution of test locations exhibiting a local event (i.e., an abrupt local deterioration of differential luminance sensitivity (DLS) by more than -10 dB between any two examinations). METHODS: The visual function of 41 glaucomatous eyes of 41 patients (16 females, 25 males, 37 to 75 years old) was examined with automated static perimetry (Tuebingen Computer Campimeter or Octopus 101-Perimeter). Stimuli were added to locally enhance the spatial resolution in suspicious regions of the visual field. The minimum follow-up was four subsequent sessions with a minimum of 2-month (median 6-month) intervals between each session. Progression was identified using a modified pointwise linear regression (PLR) method and a modified Katz criterion. The presence of events was assessed in all progressive visual fields. RESULTS: Eleven eyes (27%) showed progression over the study period (median 2.5 years, range 1.3-8.6 years). Six (55%) of these had combined progression in depth and size and five eyes (45%) progressed in depth only. Progression in size conformed always to the nerve fiber course. Seven out of 11 (64%) of the progressive scotomata detected by spatially condensed grids would have been missed by the conventional 6 degrees x 6 degrees grid. At least one event occurred in 64% of all progressive eyes. Five of 11 (46%) progressive eyes showed a cluster of events. CONCLUSIONS: The most common pattern of progression in glaucomatous visual fields is combined progression in depth and size of an existing scotoma. Applying individually condensed test grids remarkably enhances the detection rate of glaucomatous visual field deterioration (at the expense of an increased examination time) compared to conventional stimulus arrangements.


Assuntos
Glaucoma de Ângulo Aberto/diagnóstico , Glaucoma de Baixa Tensão/diagnóstico , Escotoma/diagnóstico , Testes de Campo Visual , Campos Visuais , Adulto , Idoso , Progressão da Doença , Feminino , Glaucoma de Ângulo Aberto/fisiopatologia , Humanos , Pressão Intraocular , Glaucoma de Baixa Tensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Escotoma/fisiopatologia
8.
Chemistry ; 15(14): 3403-10, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19222068

RESUMO

Racemization catalyst 5 c and the enzyme Candida antarctica lipase B were combined in a one-pot dynamic kinetic resolution (DKR) of primary amines in which a wide range of amines were transformed to their corresponding amides in up to 95 % isolated yield and >99 % ee. The DKR protocol was applicable with either isopropyl acetate or dibenzyl carbonate as the acyl donor. In the latter case, release of the free amine from the carbamate products was carried out under very mild conditions. The racemization of (S)-1-phenylethylamine with several different Ru catalysts was also evaluated. Catalyst 5 c, of the Shvo type, was able to selectively racemize amines and was also compatible with the reaction conditions used for DKR. A racemization study of three different amines with varying electronic properties was also performed. Competitive racemization of a 1:1 mixture of the deuterated and non-deuterated amine was carried out with 5 c and a primary kinetic isotope effect was observed for all three amines, providing support that the rate-determining step is beta-hydride elimination. The chemoenzymatic DKR protocol was applied to the synthesis of norsertraline (16) by using a novel route starting from readily available 1,2,3,4-tetrahydro-1-naphthylamine (1 o).


Assuntos
1-Naftilamina/análogos & derivados , Aminas/química , Lipase/metabolismo , Compostos Organometálicos/química , 1-Naftilamina/síntese química , 1-Naftilamina/química , Biocatálise , Catálise , Proteínas Fúngicas , Cinética , Sertralina/análogos & derivados , Estereoisomerismo , Especificidade por Substrato
9.
Invest Ophthalmol Vis Sci ; 50(1): 488-94, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19060285

RESUMO

PURPOSE: A new, fast-threshold strategy, German Adaptive Thresholding Estimation (GATE/GATE-i), is compared to the full-threshold (FT) staircase and the Swedish Interactive Thresholding Algorithm (SITA) Standard strategies. GATE-i is performed in the initial examination and GATE refers to the results in subsequent examinations. METHODS: Sixty subjects were recruited for participation in the study: 40 with manifest glaucoma, 10 with suspected glaucoma, and 10 with ocular hypertension. The subjects were evaluated by each threshold strategy on two separate sessions within 14 days in a randomized block design. RESULTS: SITA standard, GATE-i, and GATE thresholds were 1.2, 0.6, and 0.0 dB higher than FT. The SITA standard tended to have lower thresholds than those of FT, GATE-i, and GATE for the more positive thresholds, and also in the five seed locations. For FT, GATE-i, GATE, and SITA Standard, the standard deviations of thresholds between sessions were, respectively, 3.9, 4.5, 4.2, and 3.1 dB, test-retest reliabilities (Spearman's rank correlations) were 0.84, 0.76, 0.79, and 0.71, test-retest agreements as measured by the 95% reference interval of differences were -7.69 to 7.69, -8.76 to 9.00, -8.40 to 8.56, and -7.01 to 7.44 dB, and examination durations were 9.0, 5.7, 4.7, and 5.6 minutes. The test duration for SITA Standard increased with increasing glaucomatous loss. CONCLUSIONS: The GATE algorithm achieves thresholds that are similar to those of FT and SITA Standard, with comparable accuracy, test-retest reliability, but with a shorter test duration than FT.


Assuntos
Algoritmos , Glaucoma de Ângulo Aberto/diagnóstico , Doenças do Nervo Óptico/diagnóstico , Escotoma/diagnóstico , Testes de Campo Visual/métodos , Campos Visuais , Adulto , Feminino , Glaucoma de Ângulo Aberto/fisiopatologia , Humanos , Pressão Intraocular/fisiologia , Masculino , Hipertensão Ocular/diagnóstico , Hipertensão Ocular/fisiopatologia , Doenças do Nervo Óptico/fisiopatologia , Estudos Prospectivos , Reprodutibilidade dos Testes , Escotoma/fisiopatologia , Limiar Sensorial
10.
Acta Ophthalmol ; 86(4): 446-55, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18070224

RESUMO

PURPOSE: To determine age-dependent normative differential threshold values for the Octopus 101 instrument and to create a smooth mathematical model characterizing the age-dependency and asymmetry of the hill of vision. METHODS: Static automated perimetry within the central 30 degrees visual field (VF) was conducted with the Octopus 101 (background luminance 10 cd/m(2)) in 81 eyes of 81 ophthalmologically healthy subjects (11-12 per decade of age) aged 10-79 years. A 4-2-2 staircase strategy with three reversals was run. The test point grid consisted of 68 concentrically arranged points with test point condensation towards the VF centre, representing the approximately rotation-symmetrical 30 degrees hill of vision. Thresholds of differential luminance sensitivity (DLS) were estimated by the maximum likelihood method. A smooth mathematical model was fitted to the normative data. RESULTS: The model fit was satisfactory (r(2) = 0.74). Covariables were: age, eccentricity, angle and subject. Total random standard deviation (SD) was 1.75 dB. The residual SD exceeded 1.75 dB in the border region, was 1.5 dB within the centre and fell below 1.25 dB in a ring around the centre. Average thresholds of DLS varied with age quadratically. It is close to constant for the 10-40-year-old age group and declines ever more steeply thereafter. The effect of age on DLS in the VF increased with eccentricity. The greatest drop was located in the peripheral superior hemifield: at 25 degrees eccentricity the superior DLS was estimated to be 5.5 dB higher in 10-year-olds than in 75-year-olds. CONCLUSIONS: This new smooth model allows for the prediction of age-related normal threshold values for any stimulus location within the 30 degrees VF and thus for the calculation of global and local measures of defect such as mean defects or p-values for any type of stimulus.


Assuntos
Envelhecimento/fisiologia , Modelos Biológicos , Testes de Campo Visual/normas , Campos Visuais/fisiologia , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Limiar Sensorial/fisiologia , Testes de Campo Visual/instrumentação
11.
Ophthalmology ; 114(6): 1065-72, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17331580

RESUMO

PURPOSE: To determine the increase in isopter extent, resulting from the measurement of, and correction for, individual reaction time (RT; the latency between stimulus presentation and individual patient response), derived under the standardized conditions of semi-automated kinetic perimetry (SKP), and to model the age- and RT-corrected normative isopter values for SKP applicable to any Goldmann stimulus combination. DESIGN: Cross-sectional observational study. PARTICIPANTS: Eighty-three healthy participants aged 10 to 80 years (11-12 participants per decade of age). METHODS: One eye of each participant underwent SKP using the Octopus 101 perimeter (Haag-Streit, Koeniz, Switzerland). Four Goldmann stimulus combinations, III4e at 25 degrees/second, III4e at 5 degrees/second, I3e at 5 degrees/second, and I2e at 2 degrees/second, were presented centripetally (i.e., in a direction toward the center of the bowl) along the 8 cardinal meridia in random order. The local kinetic threshold (LKT) for each stimulus combination along each meridian was corrected for the angular distance traveled during the individual geometric mean RT and was modeled in terms of the covariables stimulus size, stimulus luminance, meridian, and age, and then presented in terms of a graphical reference plot. MAIN OUTCOME MEASURES: The variation of the LKT with RT, stimulus combination, meridian, and age. RESULTS: The median of the individual geometric mean RTs initially decreased and then increased with increase in age and was greater for stimulus combinations producing small isopters compared with those generating large isopters. Reaction time-corrected LKTs were fitted optimally by a multiple regression model (R2 = 0.86). For large (> or =size III) and intense (4e) stimuli, RT-corrected LKTs were independent of age and mainly were influenced by instrument- and facial anatomy-related characteristics. Reaction time-corrected LKTs, particularly for small (< or = size II) stimuli, exhibited a clear age dependence above the age of 40 years particularly for reduced luminance stimuli (< or = 2e), with an approximate reduction in angular extent of 2 degrees per decade for the I1e stimulus. CONCLUSIONS: The development of a graphical reference plot with mean isopters and accompanying reference intervals for age- and RT-corrected SKP, applicable to any individual patient, should facilitate the evaluation of clinical data and the implementation of a computerized alternative to manual Goldmann kinetic perimetry.


Assuntos
Testes de Campo Visual/métodos , Campos Visuais/fisiologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tempo de Reação , Valores de Referência
12.
Invest Ophthalmol Vis Sci ; 48(4): 1642-50, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17389495

RESUMO

PURPOSE: To determine the spatial characteristics of glaucomatous visual field progression in persons with glaucomatous-appearing optic neuropathy (GON) from the Diagnostic Innovations in Glaucoma Study (DIGS). METHODS: Changes in pattern deviation (PD) plot values from the average of two baseline examinations to two follow-up examinations were evaluated in test locations. All were eligible, full threshold, pattern 24-2, standard automated perimetry (SAP) examinations (Humphrey Field Analyzer II; Carl Zeiss Meditec, Inc., Dublin, CA) in visual field series from 200 patients with GON confirmed on two occasions by stereophoto review. The proportion of patients exhibiting PD plot progression was determined at each of 52 locations for patients with a baseline abnormal result (P < 5% or worse) in one or more of 52 PD locations in either the first or second baseline test for a total of 2704 location pairings for each possible level of negative PD change from -1 to -50 dB. Progression was defined as any worsening of PD plot value in the follow-up test relative to the average PD plot value in the baseline tests. Monte Carlo simulation was used to determine the significance of the observed patterns of PD plot progression. RESULTS: Changes in PDs were dependent on their location relative to abnormal PD locations in the first test. Of those patients with an abnormality at a location at baseline (mean, 0.23 +/- 0.07), the proportion of patients changing by -2 dB or more ranged between 0.09 and 0.55 (mean, 0.29 +/- 0.06) across locations. For changes of -6 dB or more, the proportions ranged between 0.00 and 0.26 (mean, 0.08 +/- 0.04) of patients. These proportions and the proportional probabilities for each of 2704 location pairings are reported for selected levels of change. The proportional probabilities are consistent with a map of the retinal nerve fiber layer bundles. CONCLUSIONS: Visual field progression occurs in retinotopically constrained patterns consistent with changes along the nerve fiber bundle.


Assuntos
Glaucoma/diagnóstico , Doenças do Nervo Óptico/diagnóstico , Escotoma/diagnóstico , Campos Visuais , Simulação por Computador , Progressão da Doença , Humanos , Método de Monte Carlo , Testes de Campo Visual
13.
Vision Res ; 46(1-2): 117-28, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16260022

RESUMO

The difference in threshold sensitivities that are found when examining the visual field (VF) with static versus kinetic perimetric methods is called stato-kinetic dissociation (SKD). In this pilot study, we describe a semi-automated procedure for quantifying SKD. Fifteen patients with VF defects were examined with kinetic and static perimetry. SKD values were defined as positive when the static scotoma was larger than the kinetic one. We found significant local variations of SKD along scotoma borders with the individual reaction time as an important criterion when determining kinetic thresholds. There was a verifiable SKD in all patients with locally negative values in eight subjects.


Assuntos
Percepção de Movimento , Escotoma/psicologia , Campos Visuais , Adulto , Idoso , Glaucoma/fisiopatologia , Glaucoma/psicologia , Humanos , Pessoa de Meia-Idade , Projetos Piloto , Tempo de Reação , Retinose Pigmentar/fisiopatologia , Retinose Pigmentar/psicologia , Escotoma/fisiopatologia , Limiar Sensorial , Testes de Campo Visual/métodos
14.
J Am Chem Soc ; 127(50): 17620-1, 2005 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-16351088

RESUMO

An efficient process for dynamic kinetic resolution of amines was developed by combining a ruthenium-catalyzed racemization with a lipase-catalyzed resolution. A variety of unfunctionalized primary amines were transformed into one enantiomer of the amide in high yield and high enantioselectivity.


Assuntos
Aminas/isolamento & purificação , Lipase/química , Aminas/química , Catálise , Proteínas Fúngicas , Iminas/química , Cinética , Lipase/metabolismo , Estereoisomerismo
15.
Ophthalmology ; 112(8): 1343-54, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15996734

RESUMO

PURPOSE: To compare quantitatively visual field (VF) results obtained using a new standardized semiautomated kinetic perimetry (SKP) with those obtained by conventional Goldmann manual kinetic perimetry (MKP) in patients with advanced VF loss. DESIGN: Prospective, single-center, observational comparative case series. SUBJECTS AND METHODS: Seventy-seven eligible patients (36 suffering from advanced retinal nerve fiber layer loss, 20 with concentric constriction of the VF, and 21 with hemianopia) were included in the study. One eye of each patient was examined on the same day with MKP and SKP. Three isopters, identical in both tests, were chosen to assess the extent of the VF loss. To compare the location and size of the corresponding isopters obtained with MKP and SKP, intersection areas of superimposed isopters were expressed as a percentage of union areas. MAIN OUTCOME MEASURES: The area and position of isopters for a defined stimulus condition obtained with both methods were compared. Test duration and patients' preference were also evaluated. RESULTS: Isopters obtained with Goldmann MKP enclosed areas smaller by 20% (confidence interval [CI], 12%-27%). The mean intersection area of Goldmann and SKP VFs was 1763.1 square degrees (CI, 1558.6-1967.7) smaller than the union for stimulus III4e over all groups of patients. Semiautomated kinetic perimetry was preferred by 60% of patients with concentric constriction of the VF. Median duration of the examination was 15 minutes and did not differ significantly between the 2 methods. CONCLUSIONS: Our results indicate that SKP isopter shape and size were very comparable to those obtained on the same eyes with MKP. Semiautomated kinetic perimetry may represent a more standardized method of kinetic perimetry, which still takes advantage of perimetrist-patient interaction to diagnose and monitor advanced VF loss in clinical practice.


Assuntos
Fibras Nervosas/patologia , Doenças do Nervo Óptico/diagnóstico , Células Ganglionares da Retina/patologia , Transtornos da Visão/diagnóstico , Testes de Campo Visual/métodos , Campos Visuais , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Cinética , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Estudos Prospectivos , Fatores de Tempo
16.
Klin Oczna ; 106(1-2 Suppl): 228-30, 2004.
Artigo em Polonês | MEDLINE | ID: mdl-15510508

RESUMO

PURPOSE: To quantify the area of isopters obtained using a new technique of kinetic visual field examination--semi-automated kinetic perimetry (SKP)--in case of advanced retinal nerve fiber layer (RNFL) loss, caused by glaucoma. MATERIAL AND METHODS: Forty-one subjects (19 men, 22 women; mean age 66.5 +/- 12.5 years) suffering from open-angle glaucoma (30 patients), normal tension glaucoma (5 patients), juvenile glaucoma (2 patients) and PEX glaucoma (4 patients) were examined, using SKP program implemented in Octopus 101 instrument (Haag-Streit, Koeniz, Switzerland). One eye of each patient was tested using three stimuli according to the Goldmann classification. The stimuli III4e and I4e were obligatory. Additionally one stimulus (I3e or I2e) was used depending on the character of the defect. The stimulus angular velocity was kept constant at the level of 3 degrees/s. Obtained visual field (VF) results were classified according to the Aulhorn classification into stage III (26 VF) and IV (15 VF). The areas of isopters were measured in deg2. RESULTS: The mean area of isopter III4e was 9860 deg2, I4e--5171 deg2, I3e--1093 deg2, I2e--1093 deg2 in the group of Aulhorn stage III. In the group of Aulhorn stage IV the mean area of isopter III4e was 7488 deg2, I4e--3736 deg2, I3e--1109 deg2 and I2e--818 deg2. The mean test time was 16 min. (range 9-25 min.), 15.7 min. in the group of Aulhorn stage III and 16.5 min. in the group of Aulhorn stage IV, respectively. CONCLUSION: SKP seems to be an effective method for quantitative assessment and evaluation of isopter and scotoma areas (in deg2). In this study it was demonstrated that in case of more advanced stages of glaucomatous visual field loss (Aulhorn stage IV), the areas of isopters appeared to be smaller.


Assuntos
Glaucoma de Ângulo Aberto/complicações , Glaucoma de Ângulo Aberto/diagnóstico , Doenças do Nervo Óptico/diagnóstico , Doenças do Nervo Óptico/etiologia , Testes de Campo Visual/métodos , Campos Visuais , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
17.
Klin Oczna ; 106(1-2 Suppl): 231-3, 2004.
Artigo em Polonês | MEDLINE | ID: mdl-15510509

RESUMO

PURPOSE: To compare the results of conventional suprathresold automated static perimetry (SASP) and a new method of kinetic visual field examination (semi-automated kinetic perimetry--SKP) in patients with advanced retinal nerve fibre layer (RNFL) defects, caused by glaucoma. MATERIAL AND METHODS: Nineteen patients (10 women and 9 men) suffering from advanced open-angle glaucoma (17 patients) and low tension glaucoma (2 patients) were enrolled in this study. The mean age was 65.3 years (range 49.0-82.9 years). One eye of each subject was examined with SKP and SASP, both implemented in Octopus 101 perimeter (Haag-Streit, Koeniz, Switzerland) on the same day. The examiner using SKP did not know the SASP results. The static visual field examination was performed first. In order to compare visual fields results obtained with both methods, only central 30 degree area of the visual fields was taken into consideration. The area obtained by creating a virtual isopter (option of SKP software) located between the position of defective and intact visual field regions of SASP and the area of I4e isopter obtained with SKP (stimulus angular velocity 3 degrees/s) were measured in deg2 and compared. RESULTS: The mean area (+/-SD) of I4e isopter obtained with SKP was 1882 deg2 (+/- 510 deg2) and the mean area of SASP 30 degree visual field was 1737 deg2 (+/- 546 deg2). This difference was not statistically significant. CONCLUSION: Quantitative comparison of static and kinetic perimetry is a difficult task to perform. The SKP software offers a possibility of direct quantitative assessment of the area of each isopters in deg2. This study shows that the results of visual field examinations obtained with both methods in this group do not differ significantly between SASP and SKP.


Assuntos
Glaucoma de Ângulo Aberto/diagnóstico , Doenças do Nervo Óptico/diagnóstico , Testes de Campo Visual/métodos , Campos Visuais , Idoso , Idoso de 80 Anos ou mais , Feminino , Glaucoma de Ângulo Aberto/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Doenças do Nervo Óptico/complicações
19.
Klin Oczna ; 106(6): 798-801, 2004.
Artigo em Polonês | MEDLINE | ID: mdl-15787186

RESUMO

The manual kinetic perimetry using Goldmann instrument is still widely used and remains a "gold standard" in examining patients with any kind of advanced visual field loss and impaired co-operability. Nevertheless, Goldmann instrument has several disadvantages, such as examiner dependence, response variability, lack of standardization of parameters, poor repeatability. The latest development in kinetic perimetry, which was realized at the University Eye Hospital in Tuebingen (Germany) is semi-automated kinetic perimetry (SKP), using Octopus 101 instrument (Interzeag/Haag-Streit, Koeniz-Bern, Switzerland). It is an examiner-independent, standardized and reproducible method. Additionally, obtained results can be corrected for the mean individual reaction time. This paper will briefly present characteristic, advantages and application of SKP in clinical practice.


Assuntos
Oftalmopatias/diagnóstico , Oftalmopatias/fisiopatologia , Cinética , Testes de Campo Visual/instrumentação , Campos Visuais/fisiologia , Humanos
20.
Klin Oczna ; 106(3 Suppl): 500-2, 2004.
Artigo em Polonês | MEDLINE | ID: mdl-15636249

RESUMO

PURPOSE: To assess the applicability of a new technique of kinetic visual field examination--semi-automated kinetic perimetry (SKP)--in patients suffering from the visual field defects due to retinitis pigmentosa. METHODS: Thirty-five patients (19 women, 16 men: mean age 38.4 years) suffering from retinitis pigmentosa (10 with with Usher syndrome, one with Bardet-Biedl syndrome and one with Refsum syndrome) were examined using SKP software, implemented in Octopus 101 instrument (Haag-Streit, Koeniz, Switzerland). Three stimuli (1114e and 14e obligatory) were used to assess the hill of vision of each patient. The area of each isopter was measured in deg2. The test time was measured automatically in minutes. RESULTS: The visual field results were classified as complete or incomplete midperipheral "ring scotoma" (group I--13 patients) and concentric loss of the visual field (group II--22 patients). The area of 1114e isopter was 6147.5 deg2 in the group I and 1961.7 deg2 in the group II. The area of 14e isopter was 1468.4 deg2 and 781.7 deg2, respectively. The mean test time was 10 min. (range 4-20 min.): 8 min. in the group I and 13 min. in the group II. CONCLUSIONS: There is a large diversity of patterns of the visual field loss in retinitis pigmentosa. SKP, in contrary to widely used manual perimeter, gives a possibility of quantification of the visual field area. Future studies may be able to monitor the progression of the visual field loss caused by retinitis pigmentosa.


Assuntos
Retinose Pigmentar/diagnóstico , Testes de Campo Visual/métodos , Campos Visuais , Adulto , Progressão da Doença , Feminino , Humanos , Masculino
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