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Ulrich Schiefer - One of the best experts on this subject based on the ideXlab platform.
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Comparison of advanced visual field defects measured with the Tübingen Mobile Campimeter and the Octopus 101 perimeter.
European journal of ophthalmology, 2010Co-Authors: A. Bruckmann, Reinhard Vonthein, Nicholas J. Volpe, J Paetzold, Ulrich SchieferAbstract: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 Tubingen 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.
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Specification of progression in glaucomatous visual field loss, applying locally condensed stimulus arrangements
Graefe's Archive for Clinical and Experimental Ophthalmology, 2009Co-Authors: Jukka Nevalainen, Reinhard Vonthein, Pamela A Sample, Jens Paetzold, Eleni Papageorgiou, John P. Pascual, Elke Krapp, Bettina Selig, Ulrich SchieferAbstract: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° × 6° 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 -10dB 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° × 6° 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.
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scotoma mapping by semi automated kinetic perimetry the effects of stimulus properties and the speed of subjects responses
Acta Ophthalmologica Scandinavica, 2006Co-Authors: Jan Dolderer, Reinhard Vonthein, Ulrich Schiefer, Chris A Johnson, William M HartAbstract:Purpose: The study aimed firstly to determine the effects of stimulus variables on the detection of a scotoma border and, secondly, to study the reproducibility of the method during semi-automated kinetic perimetry. Methods: The size of the physiological blind spot in 18 young normal subjects was measured with a video-campimetric device, the Tubingen computer Campimeter (TCC). Kinetic stimuli of two different sizes and at four different levels of lumi- nance were presented. Examinations were repeated within 2 weeks. Measurements were corrected for individual response times and the area of the blind spot was computed. The effects of stimulus strength and size and the repeatability of blind spot measurements were evaluated by an analysis of variance. Results: The physiological blind spot showed significant inter- and intraindivi- dual variations in size (least square means ranging from 17 to 49 square degrees), with a standard deviation of 6.8 square degrees. The measured size of the blind spot increased as a function of decreasing stimulus value, by reducing either the relative brightness or the size of stimuli. Use of a correction for each subject's speed of responses nearly halved the level of random variance. The temporal sequence of measurements (the order in which they were performed) had no apparent effect on the calculated values of blind spot size. Conclusions: Semi-automated kinetic perimetry can determine the size of the phy- siological blind spot with good repeatability in young, normal subjects. Determination of each individual's speed of response and inclusion of this variable in the calculations reduced variance of the measure significantly. This study confirmed the presence of considerable interindividual differences in the size of the physiological blind spot.
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Pupil size and Perimetry—a pharmacological model using increment and decrement stimuli
Graefe's Archive for Clinical and Experimental Ophthalmology, 2005Co-Authors: David D. Martin, Reinhard Vonthein, Helmut Wilhelm, Ulrich SchieferAbstract:Background To assess the influence of natural and pharmacologically induced pupil size fluctuations on differential luminance sensitivity threshold (DLS) using bright (increment) and dark (decrement) stimuli. Methods Twelve healthy volunteers (20–30 years) were examined under the effect of phenylephrine 2%, dapiprazole 0.5%, and placebo. Pupil size was recorded by infra-red video camera in sessions without and with visual field examination (Tübingen Computer Campimeter). DLS was estimated at 9 locations within the central 20° visual field, using bright and dark 26 min-of-arc-stimuli (10 cd/m^2 background, 4-2-1 dB thresholding strategy, four reversals). Results There were substantial inter-individual differences in pupil size and pupil size fluctuations. Intra-individual differences were small. Independently of medication, pupil size fluctuations were reduced by more than one-third when a subject was undergoing perimetric examination. Pupil size affected DLS on its own (slope 0.21 dB/mm; 95% CI: 0.09–0.33 dB/mm), differently at different stimulus locations, and to a greater extent with increment than with decrement stimuli (slope difference 0.13 dB/mm; 95% CI: 0.00–0.26 dB/mm). Conclusions Campimetric examinations have a stabilising effect on pupil size fluctuations. Pupil size affects DLS with bright stimuli more than with dark stimuli; in normal young subjects this effect is not relevant for clinical or normative studies.
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Factors influencing reaction time during automated kinetic perimetry on the tübingen computer Campimeter
Investigative ophthalmology & visual science, 2005Co-Authors: Stephan T. Becker, Reinhard Vonthein, Nicholas J. Volpe, Ulrich SchieferAbstract:PURPOSE: To determine the effect of age, examination, location, luminance, subject, and vigilance on reaction time (RT) in automated kinetic perimetry. METHODS: Thirty-six normal volunteers (20-70 years old) underwent kinetic campimetric examinations, during which RTs (time from appearance of a stimulus to response) were recorded. Stimuli with a diameter of 26 minutes of arc (Goldmann III) were presented on horizontal vectors with an angular velocity of 2 deg/s. Thirty-two positions in the 30 degrees radius visual field were tested six times, at luminance levels of 41.62 and 110 cd/m2 (background 10 cd/m2). An analysis of RT variance (ANCOVA) was performed. RESULTS: Median RT increased with age from 370 ms (20-30-year-old subjects) to 440 ms (60-70-year-old subjects). There was a strong dependency of RT from the individual subjects examined (means range, 313-411 ms), from the course of one examination period, from the examination and stimulus luminance, and from the location in the visual field. CONCLUSIONS: Reaction time during automated kinetic perimetry varies considerably. This study shows that the factors of age, the subject examined, his or her daily condition, the course within one examination period, and the stimulus location and luminance are of relevance. For a much more reliable prediction of individual RTs and thus a precise assessment of local kinetic thresholds, application of some additional kinetic stimuli (RT time vectors) within the intact visual field areas is necessary.
Reinhard Vonthein - One of the best experts on this subject based on the ideXlab platform.
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Comparison of advanced visual field defects measured with the Tübingen Mobile Campimeter and the Octopus 101 perimeter.
European journal of ophthalmology, 2010Co-Authors: A. Bruckmann, Reinhard Vonthein, Nicholas J. Volpe, J Paetzold, Ulrich SchieferAbstract: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 Tubingen 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.
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Specification of progression in glaucomatous visual field loss, applying locally condensed stimulus arrangements
Graefe's Archive for Clinical and Experimental Ophthalmology, 2009Co-Authors: Jukka Nevalainen, Reinhard Vonthein, Pamela A Sample, Jens Paetzold, Eleni Papageorgiou, John P. Pascual, Elke Krapp, Bettina Selig, Ulrich SchieferAbstract: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° × 6° 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 -10dB 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° × 6° 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.
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scotoma mapping by semi automated kinetic perimetry the effects of stimulus properties and the speed of subjects responses
Acta Ophthalmologica Scandinavica, 2006Co-Authors: Jan Dolderer, Reinhard Vonthein, Ulrich Schiefer, Chris A Johnson, William M HartAbstract:Purpose: The study aimed firstly to determine the effects of stimulus variables on the detection of a scotoma border and, secondly, to study the reproducibility of the method during semi-automated kinetic perimetry. Methods: The size of the physiological blind spot in 18 young normal subjects was measured with a video-campimetric device, the Tubingen computer Campimeter (TCC). Kinetic stimuli of two different sizes and at four different levels of lumi- nance were presented. Examinations were repeated within 2 weeks. Measurements were corrected for individual response times and the area of the blind spot was computed. The effects of stimulus strength and size and the repeatability of blind spot measurements were evaluated by an analysis of variance. Results: The physiological blind spot showed significant inter- and intraindivi- dual variations in size (least square means ranging from 17 to 49 square degrees), with a standard deviation of 6.8 square degrees. The measured size of the blind spot increased as a function of decreasing stimulus value, by reducing either the relative brightness or the size of stimuli. Use of a correction for each subject's speed of responses nearly halved the level of random variance. The temporal sequence of measurements (the order in which they were performed) had no apparent effect on the calculated values of blind spot size. Conclusions: Semi-automated kinetic perimetry can determine the size of the phy- siological blind spot with good repeatability in young, normal subjects. Determination of each individual's speed of response and inclusion of this variable in the calculations reduced variance of the measure significantly. This study confirmed the presence of considerable interindividual differences in the size of the physiological blind spot.
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Pupil size and Perimetry—a pharmacological model using increment and decrement stimuli
Graefe's Archive for Clinical and Experimental Ophthalmology, 2005Co-Authors: David D. Martin, Reinhard Vonthein, Helmut Wilhelm, Ulrich SchieferAbstract:Background To assess the influence of natural and pharmacologically induced pupil size fluctuations on differential luminance sensitivity threshold (DLS) using bright (increment) and dark (decrement) stimuli. Methods Twelve healthy volunteers (20–30 years) were examined under the effect of phenylephrine 2%, dapiprazole 0.5%, and placebo. Pupil size was recorded by infra-red video camera in sessions without and with visual field examination (Tübingen Computer Campimeter). DLS was estimated at 9 locations within the central 20° visual field, using bright and dark 26 min-of-arc-stimuli (10 cd/m^2 background, 4-2-1 dB thresholding strategy, four reversals). Results There were substantial inter-individual differences in pupil size and pupil size fluctuations. Intra-individual differences were small. Independently of medication, pupil size fluctuations were reduced by more than one-third when a subject was undergoing perimetric examination. Pupil size affected DLS on its own (slope 0.21 dB/mm; 95% CI: 0.09–0.33 dB/mm), differently at different stimulus locations, and to a greater extent with increment than with decrement stimuli (slope difference 0.13 dB/mm; 95% CI: 0.00–0.26 dB/mm). Conclusions Campimetric examinations have a stabilising effect on pupil size fluctuations. Pupil size affects DLS with bright stimuli more than with dark stimuli; in normal young subjects this effect is not relevant for clinical or normative studies.
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Factors influencing reaction time during automated kinetic perimetry on the tübingen computer Campimeter
Investigative ophthalmology & visual science, 2005Co-Authors: Stephan T. Becker, Reinhard Vonthein, Nicholas J. Volpe, Ulrich SchieferAbstract:PURPOSE: To determine the effect of age, examination, location, luminance, subject, and vigilance on reaction time (RT) in automated kinetic perimetry. METHODS: Thirty-six normal volunteers (20-70 years old) underwent kinetic campimetric examinations, during which RTs (time from appearance of a stimulus to response) were recorded. Stimuli with a diameter of 26 minutes of arc (Goldmann III) were presented on horizontal vectors with an angular velocity of 2 deg/s. Thirty-two positions in the 30 degrees radius visual field were tested six times, at luminance levels of 41.62 and 110 cd/m2 (background 10 cd/m2). An analysis of RT variance (ANCOVA) was performed. RESULTS: Median RT increased with age from 370 ms (20-30-year-old subjects) to 440 ms (60-70-year-old subjects). There was a strong dependency of RT from the individual subjects examined (means range, 313-411 ms), from the course of one examination period, from the examination and stimulus luminance, and from the location in the visual field. CONCLUSIONS: Reaction time during automated kinetic perimetry varies considerably. This study shows that the factors of age, the subject examined, his or her daily condition, the course within one examination period, and the stimulus location and luminance are of relevance. For a much more reliable prediction of individual RTs and thus a precise assessment of local kinetic thresholds, application of some additional kinetic stimuli (RT time vectors) within the intact visual field areas is necessary.
U. Schiefer - One of the best experts on this subject based on the ideXlab platform.
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increased detection rate of glaucomatous visual field damage with locally condensed grids a comparison between fundus oriented perimetry and conventional visual field examination
Archives of Ophthalmology, 2003Co-Authors: U. Schiefer, Reinhard Vonthein, A Malsam, M Flad, F Stumpp, J Paetzold, Oliver P Denk, Pamela A SampleAbstract:Objective To compare detection rates of glaucomatous visual field defects (VFDs) between the conventional 6° × 6° stimulus grid and locally condensed target arrangements in morphologically suspicious regions. Methods A total of 66 eyes of 66 patients with glaucoma or patients suspected of having glaucoma (34 females and 32 males; age range, 14-85 years) were enrolled in this study. Individual, local target condensation was realized by fundus-oriented perimetry (FOP) using a Campimeter and compared with the results of conventional automated perimetry (CAP), obtained with the Humphrey Field Analyzer (30-2 grid). Results Twenty-three of the 66 patients showed normal findings with both methods; 27 had concordantly pathological results. In 15 patients we obtained normal findings with CAP, whereas FOP revealed early glaucomatous VFDs. Only one patient showed VFDs with CAP, whereas FOP results were normal. Scotoma detection rates significantly differed between the 2 methods (P .25, sign test). This indicated that the target pattern, rather than the perimetric device, was most relevant for detecting glaucomatous VFDs. Follow-up throughout a series of 3 subsequent sessions at 6-month intervals revealed repeatable results in more than two thirds of all eyes for both FOP and CAP. Conclusions Fundus-oriented perimetry that uses individually condensed test grids significantly increases the detection rate of glaucomatous VFDs in morphologically conspicuous areas compared with CAP using equidistant (6° × 6°) target arrangements. Repeatability is comparable between both methods.
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Evaluation of glaucomatous visual field loss with locally condensed grids using fundus-oriented perimetry (FOP).
European journal of ophthalmology, 2001Co-Authors: U. Schiefer, A Malsam, M Flad, F Stumpp, T J Dietrich, J Paetzold, R Vonthein, M Knorr, P O DenkAbstract:We compared detection rates of glaucomatous visual field defects (VFDs) between a conventional rectangular stimulus grid and locally condensed test point arrangements in morphologically suspicious regions. Humphrey Field Analyzer model 630 (HFA I, program 30-2 with a rectangular 6 degrees x 6 degrees grid) was used as the conventional perimetric method. Individual local test-point condensation was realized by fundus-oriented perimetry (FOP) on the Tuebingen Computer Campimeter (TCC). Of a total of 66 glaucoma patients, or suspected sufferers, 23 showed normal findings and 27 showed pathological findings with both methods. In 15 cases we found normal visual fields in HFA 30-2, whereas FOP revealed early glaucomatous functional damage. Only one case showed pathological HFA results, while FOP was normal. Detection rates of VFDs significantly differed between the two methods (p < 0.001; sign test). FOP, using individually condensed test grids, significantly increases detection rates of glaucomatous VFDs in morphologically suspicuous areas compared with a conventional HFA 30-2 technique using equidistant rectangular (6 degrees x 6 degrees) test point arrangements.
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A new white-noise Campimeter
Klinische Monatsblatter fur Augenheilkunde, 1993Co-Authors: U. Schiefer, G. Stercken-sorrentiAbstract:In this prototype white-noise field is now generated on a high definition adjustable 19" colour monitor. With the help of a "touch-screen" the patient can draw the borders of his scotoma himself. As the white-noise stimulus is produced by software, there is a much greater variability of white-noise field specifications (brightness, intensity of noise, colour, ...). Furthermore, these parameters can be changed exclusively in circumscribed parts of the noise field (e.g. in a scotoma area). By that way a simulation or even a quantification of perceived noise field defects can be realized. Fixation is controlled with the help of an IR video camera. Input and storage of data as well as their presentation and output (on a Laserwriter) have been substantially improved.
E Mutlukan - One of the best experts on this subject based on the ideXlab platform.
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A comparison of automated static dark stimuli with the Humphrey STATPAC program in glaucomatous visual field loss.
The British journal of ophthalmology, 1994Co-Authors: E MutlukanAbstract:Visual field examination is conventionally performed with bright stimuli on a dark background. Dark stimuli on a bright background, however, may provide different information as light increases and decreases are subject to parallel processing in the visual pathway. Twenty five eyes with primary open angle glaucoma and visual field loss were examined with the Humphrey visual field analyser thresholding program 30-2 and the computer assisted moving eye Campimeter (CAMEC) using static dark stimuli at four different Weber contrast levels of -10 (n = 9), -22 (n = 25), -37 (n = 14), and -76% (n = 25) on a cathode ray tube with a background luminance of 10 cd/m2. The cumulative results obtained with STATPAC 'pattern deviation' empirical probability maps and the results from each contrast of the dark stimulus at identical test locations were compared at eccentricity annuli bands of 4-9, 10-20, and 21-28 degrees. Dark stimuli of lower contrast provided higher abnormal point detection rates. Furthermore, visual field defects to the low contrast dark stimuli were more extensive than those to the luminous stimuli. In conclusion, dark stimuli allowed the delineation between glaucomatous field defects and the normal regions in the central visual field.
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A back propagation neural network for the classification of visual field data
Physics in Medicine and Biology, 1993Co-Authors: David Keating, E Mutlukan, A Evans, J Mcgarvie, Bertil DamatoAbstract:The computer assisted moving eye Campimeter (CAMEC) is a visual field analyser that uses a moving target to hold the patient's fixation while the stimuli are presented. A neural network has been used to classify visual field data in the CAMEC format. This has the potential to provide self-testing diagnostic visual field examinations without the presence of skilled clinical personnel. A three-layer back propagation network was designed, with 110 units in the input layer, each unit corresponding to a test point on the CAMEC grid, a hidden layer of 40 units and an output layer of 22 units, each one corresponding to a particular type of visual field defect. Four hundred and ninety simulated field plots were generated in the CAMEC format by experienced ophthalmologists. These data were split into a training sets of 440 plots and a test set of 50 plots. Training of the neural network was accomplished by cycling the training set up to 50,000 times through the network. The effect of changing the number of hidden units was investigated using the test set of field plots. Optimizing the network configuration results in a classification accuracy of 98.2% for the training set of data and 96% for the test set.
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Clinical evaluation of a multi-fixation Campimeter for the detection of glaucomatous visual field loss.
The British journal of ophthalmology, 1993Co-Authors: E Mutlukan, Bertil Damato, J L JayAbstract:The multi-fixation glaucoma screening chart, which uses the oculokinetic perimetry (OKP) technique, is a hand-held tangent screen with a central black test stimulus on a white background and a series of 26 numbered fixation targets arranged around the stimulus at various locations. When the numbers on the chart are read by the patient from 40 cm distance, the test stimulus passes through the relevant parts of the central visual field which are most vulnerable to glaucomatous damage. The test is positive (that is, abnormal) if at least one fixation number is associated with consistent disappearance of the stimulus. The OKP test was performed in 222 eyes of 126 glaucoma patients (aged 16-91 years) and 186 right eyes of 186 normal individuals (aged 19-86 years) using a 1.5 mm diameter stimulus. A further 144 eyes of 88 glaucoma patients (aged 60-85 years) and 31 right eyes of 31 normal individuals (aged 60-85 years) were tested with a 3 mm diameter stimulus. All eyes were also tested with conventional perimetry and the results of the conventional perimetry were categorised according to the Aulhorn-Karmeyer classification by four ophthalmologists without any knowledge of the OKP results. When the 1.5 mm stimulus was used, a true positive OKP result was obtained in 45% of eyes with relative scotomas, 81% of eyes with small absolute scotomas separate from the blind spot and 100% of eyes with more severe visual field defects.(ABSTRACT TRUNCATED AT 250 WORDS)
Pamela A Sample - One of the best experts on this subject based on the ideXlab platform.
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Specification of progression in glaucomatous visual field loss, applying locally condensed stimulus arrangements
Graefe's Archive for Clinical and Experimental Ophthalmology, 2009Co-Authors: Jukka Nevalainen, Reinhard Vonthein, Pamela A Sample, Jens Paetzold, Eleni Papageorgiou, John P. Pascual, Elke Krapp, Bettina Selig, Ulrich SchieferAbstract: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° × 6° 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 -10dB 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° × 6° 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.
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increased detection rate of glaucomatous visual field damage with locally condensed grids a comparison between fundus oriented perimetry and conventional visual field examination
Archives of Ophthalmology, 2003Co-Authors: U. Schiefer, Reinhard Vonthein, A Malsam, M Flad, F Stumpp, J Paetzold, Oliver P Denk, Pamela A SampleAbstract:Objective To compare detection rates of glaucomatous visual field defects (VFDs) between the conventional 6° × 6° stimulus grid and locally condensed target arrangements in morphologically suspicious regions. Methods A total of 66 eyes of 66 patients with glaucoma or patients suspected of having glaucoma (34 females and 32 males; age range, 14-85 years) were enrolled in this study. Individual, local target condensation was realized by fundus-oriented perimetry (FOP) using a Campimeter and compared with the results of conventional automated perimetry (CAP), obtained with the Humphrey Field Analyzer (30-2 grid). Results Twenty-three of the 66 patients showed normal findings with both methods; 27 had concordantly pathological results. In 15 patients we obtained normal findings with CAP, whereas FOP revealed early glaucomatous VFDs. Only one patient showed VFDs with CAP, whereas FOP results were normal. Scotoma detection rates significantly differed between the 2 methods (P .25, sign test). This indicated that the target pattern, rather than the perimetric device, was most relevant for detecting glaucomatous VFDs. Follow-up throughout a series of 3 subsequent sessions at 6-month intervals revealed repeatable results in more than two thirds of all eyes for both FOP and CAP. Conclusions Fundus-oriented perimetry that uses individually condensed test grids significantly increases the detection rate of glaucomatous VFDs in morphologically conspicuous areas compared with CAP using equidistant (6° × 6°) target arrangements. Repeatability is comparable between both methods.