The Experts below are selected from a list of 1404 Experts worldwide ranked by ideXlab platform
Stuart L Graham - One of the best experts on this subject based on the ideXlab platform.
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comparison of visual field sensitivities between the medmont Automated Perimeter and the humphrey field analyser
Clinical and Experimental Ophthalmology, 2010Co-Authors: John Landers, Alok Sharma, Ivan Goldberg, Stuart L GrahamAbstract:Background: Two commonly used Perimeters in Australia and in many parts of Asia are the Humphrey field analyser II (HFA) and the Medmont Automated Perimeter (MAP). Each device maps the incremental light threshold of the visual field and describes the sensitivity at each point in ‘decibels’ (dB); however, these values are not interchangeable between devices. This study was designed to compare directly the sensitivity values of HFA and MAP visual fields. Methods: Sixty-three subjects who had suspected glaucoma, ocular hypertension or glaucoma, or were normal controls were recruited selectively. One eye from each patient was tested with the MAP and HFA in random order on the same day. Corresponding points between the two tests were identified and their sensitivities were compared. Results: Sensitivities between MAP and HFA were strongly correlated (r2 = 0.45; P < 0.0001), with the relationship between them being described by the linear equation: MAP = 0.75*(HFA) − 0.87. On average, across the entire field MAP sensitivities were 7.4 dB (standard deviation 4.6 dB) lower than HFA. However, this relationship was modified by eccentricity and field sensitivity loss. Conclusion: Visual field sensitivities for MAP and HFA may be related by a linear relationship. Theoretical and clinical predictions that this difference may be on average approximately 5 dB have been confirmed.
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a comparison of global indices between the medmont Automated Perimeter and the humphrey field analyzer
British Journal of Ophthalmology, 2007Co-Authors: John A Landers, Alok Sharma, Ivan Goldberg, Stuart L GrahamAbstract:Background: Two commonly used Perimeters in Australia are the Humphrey Field Analyzer II (HFA) and the Medmont Automated Perimeter (MAP). Each device describes the visual field in terms of numerical values called 9global indices9, however these values are not interchangeable between devices. This study was designed to compare directly the global indices of HFA and MAP visual fields. Methods: 63 subjects who were glaucoma suspects, ocular hypertensives, glaucoma patients, or normal controls were recruited selectively. Each patient was tested with the MAP and HFA. Global indices were then compared between tests. These included Mean Deviation (MD) and Pattern Standard Deviation (PSD) from HFA and Average Defect (AD) and Pattern Defect (PD) from MAP. Results: Results of MD and PSD were strongly correlated with those of AD and PD respectively. The relationship between them could be described in terms of two polynomial equations: AD = 0.94 + 1.31(MD) + 0.02(MD) 2 and PD = 2.21(PSD) - 0.05(PSD) 2 - 0.006. These nonlinear relationships may be the result of differences in testing method (test stimulus spectrum, number of testing locations or background luminance) or differences in the way each global index was calculated. Conclusion: The AD and PD results obtained from the MAP may be substituted for the MD and PSD of the HFA after an appropriate conversion.
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a comparison of global indices between the medmont Automated Perimeter and the humphrey field analyzer short running title comparing medmont with humphrey global indices
2007Co-Authors: John A Landers, Alok Sharma, Ivan Goldberg, Stuart L GrahamAbstract:Background: Two commonly used Perimeters in Australia are the Humphrey Field Analyzer II (HFA) and the Medmont Automated Perimeter (MAP). Each device describes the visual field in terms of numerical values called ‘global indices’, however these values are not interchangeable between devices. This study was designed to compare directly the global indices of HFA and MAP visual fields. Methods: 63 subjects who were glaucoma suspects, ocular hypertensives, glaucoma patients, or normal controls were recruited selectively. Each patient was tested with the MAP and HFA. Global indices were then compared between tests. These included Mean Deviation (MD) and Pattern Standard Deviation (PSD) from HFA and Average Defect (AD) and Pattern Defect (PD) from MAP. Results: Results of MD and PSD were strongly correlated with those of AD and PD respectively. The relationship between them could be described in terms of two polynomial equations: AD = 0.94 + 1.31(MD) + 0.02(MD) and PD = 2.21(PSD) 0.05(PSD) 0.006. These nonlinear relationships may be the result of differences in testing method (test stimulus spectrum, number of testing locations or background luminance) or differences in the way each global index was calculated. Conclusion: The AD and PD results obtained from the MAP may be substituted for the MD and PSD of the HFA after an appropriate conversion.
F Fankhauser - One of the best experts on this subject based on the ideXlab platform.
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a comparison of unweighted and fluctuation weighted indices within the central 28 of glaucomatous visual fields measured with the octopus Automated Perimeter
International Ophthalmology, 1991Co-Authors: A T Funkhouser, F FankhauserAbstract:The main visual field indices of Flammer and the analogous ones of Heijl have been compared based on a population of 113 glaucomatous visual fields. It is shown that for the population studied, the differences between the two sets of indices are negligible for Octopus G1 program results and that they may thus be used interchangeably.
J P Renard - One of the best experts on this subject based on the ideXlab platform.
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a comparison of visual field testing with a new Automated Perimeter the compass visual field analyser and the humphrey visual field analyser
Acta Ophthalmologica, 2016Co-Authors: J R Fenolland, S Bonnel, R Rosenberg, D Sendon, W Ghazal, J M Giraud, J P RenardAbstract:Purpose To compare a new visual field analyser, Compass, that included an eye tracking and scanning ophthalmoloscopy to Humphrey visual field analyser (HFA). Methods Prospective cross study design. Patients were included after a complete examination: all were indemn of ocular disease except glaucoma. Visual acuity was 20/20 for each eye and spherical equivalent ranged from +3 to −3 D. Patients were randomly assigned to one instrument. HFA was performed with a 24-2 SITA standard strategy comparable to the Compass 24-2 ZEST strategy. Both eyes were tested and 30 min after where screened with the other instrument. MD, PSD and exam duration were compared for both devices using a Wilcoxon signed-rank test. Agreement was evaluated with a Bland-Altman graph for each parameter. Results The study included 67 eyes of 30 patients. This population was decomposed as: 13 normal eyes, 28 OHT or glaucoma suspect and 26 glaucoma. Patients’ demographics were (mean ± SD): age 66.3 ± 13.0 years, pachymetry 527.6 ± 28.95 μm, axial length 23.73 ± 0.99 mm, spherical equivalent −0.004 ± 1.3 D. 65 HFA vs. 62 compass visual fields were reliable (ns). Mean Deviation was equivalent for HFA and Compass instruments: −1.6 ± 2.6 vs. −1.4 ± 2.8 dB (p = 0.28). Pattern Standard Deviation was significantly higher for the Compass 3.9 ± 2.4 vs. 2.4 ± 1.9 dB for the HFA (p < 0.0001). Examen duration was also longer for the Compass 351 ± 83 s vs. 318 ± 48 s for the HFA (p = 0.0164). Bland Altman plots showed a good agreement between HFA and Compass. Conclusions This study shows that MD and failure rate were comparable between both instruments, PSD and examination duration were slightly higher for the Compass. Agreement was good between both instruments. As most of the patients included had already performed a HFA before, this may explain the duration difference between and should be consider in further explorations.
Ivan Goldberg - One of the best experts on this subject based on the ideXlab platform.
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A comparison of global indices between the Medmont Automated Perimeter and the Humphrey Field Analyzer
2020Co-Authors: John Landers, Alok Sharma, Ivan GoldbergAbstract:Background: Two commonly used Perimeters in Australia are the Humphrey Field Analyzer II (HFA) and the Medmont Automated Perimeter (MAP). Each device describes the visual field in terms of numerical values called global indices; however, these values are not interchangeable between devices. This study was designed to directly compare the global indices of HFA and MAP visual fields. Methods: 63 subjects who had suspected glaucoma, ocular hypertension or glaucoma, or were normal controls were recruited selectively. Each patient was tested with the MAP and HFA. Global indices were then compared between tests. These included mean deviation (MD) and pattern standard deviation (PSD) from the HFA and average defect (AD) and pattern defect (PD) from the MAP. Results: The MD and PSD results were strongly correlated with the AD and PD results, respectively. The relationship between them could be described in terms of two polynomial equations: AD = 0.94+1.31(MD)+0.02(MD) 2 and PD = 2.21(PSD)-0.05(PSD) 2 -0.006. These non-linear relationships may be the result of differences in testing method (test stimulus spectrum, number of testing locations or background luminance) or differences in the way each global index was calculated. Conclusion: The AD and PD results obtained from the MAP may be substituted for the MD and PSD results from the HFA after appropriate conversion
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comparison of visual field sensitivities between the medmont Automated Perimeter and the humphrey field analyser
Clinical and Experimental Ophthalmology, 2010Co-Authors: John Landers, Alok Sharma, Ivan Goldberg, Stuart L GrahamAbstract:Background: Two commonly used Perimeters in Australia and in many parts of Asia are the Humphrey field analyser II (HFA) and the Medmont Automated Perimeter (MAP). Each device maps the incremental light threshold of the visual field and describes the sensitivity at each point in ‘decibels’ (dB); however, these values are not interchangeable between devices. This study was designed to compare directly the sensitivity values of HFA and MAP visual fields. Methods: Sixty-three subjects who had suspected glaucoma, ocular hypertension or glaucoma, or were normal controls were recruited selectively. One eye from each patient was tested with the MAP and HFA in random order on the same day. Corresponding points between the two tests were identified and their sensitivities were compared. Results: Sensitivities between MAP and HFA were strongly correlated (r2 = 0.45; P < 0.0001), with the relationship between them being described by the linear equation: MAP = 0.75*(HFA) − 0.87. On average, across the entire field MAP sensitivities were 7.4 dB (standard deviation 4.6 dB) lower than HFA. However, this relationship was modified by eccentricity and field sensitivity loss. Conclusion: Visual field sensitivities for MAP and HFA may be related by a linear relationship. Theoretical and clinical predictions that this difference may be on average approximately 5 dB have been confirmed.
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a comparison of global indices between the medmont Automated Perimeter and the humphrey field analyzer
British Journal of Ophthalmology, 2007Co-Authors: John A Landers, Alok Sharma, Ivan Goldberg, Stuart L GrahamAbstract:Background: Two commonly used Perimeters in Australia are the Humphrey Field Analyzer II (HFA) and the Medmont Automated Perimeter (MAP). Each device describes the visual field in terms of numerical values called 9global indices9, however these values are not interchangeable between devices. This study was designed to compare directly the global indices of HFA and MAP visual fields. Methods: 63 subjects who were glaucoma suspects, ocular hypertensives, glaucoma patients, or normal controls were recruited selectively. Each patient was tested with the MAP and HFA. Global indices were then compared between tests. These included Mean Deviation (MD) and Pattern Standard Deviation (PSD) from HFA and Average Defect (AD) and Pattern Defect (PD) from MAP. Results: Results of MD and PSD were strongly correlated with those of AD and PD respectively. The relationship between them could be described in terms of two polynomial equations: AD = 0.94 + 1.31(MD) + 0.02(MD) 2 and PD = 2.21(PSD) - 0.05(PSD) 2 - 0.006. These nonlinear relationships may be the result of differences in testing method (test stimulus spectrum, number of testing locations or background luminance) or differences in the way each global index was calculated. Conclusion: The AD and PD results obtained from the MAP may be substituted for the MD and PSD of the HFA after an appropriate conversion.
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a comparison of global indices between the medmont Automated Perimeter and the humphrey field analyzer short running title comparing medmont with humphrey global indices
2007Co-Authors: John A Landers, Alok Sharma, Ivan Goldberg, Stuart L GrahamAbstract:Background: Two commonly used Perimeters in Australia are the Humphrey Field Analyzer II (HFA) and the Medmont Automated Perimeter (MAP). Each device describes the visual field in terms of numerical values called ‘global indices’, however these values are not interchangeable between devices. This study was designed to compare directly the global indices of HFA and MAP visual fields. Methods: 63 subjects who were glaucoma suspects, ocular hypertensives, glaucoma patients, or normal controls were recruited selectively. Each patient was tested with the MAP and HFA. Global indices were then compared between tests. These included Mean Deviation (MD) and Pattern Standard Deviation (PSD) from HFA and Average Defect (AD) and Pattern Defect (PD) from MAP. Results: Results of MD and PSD were strongly correlated with those of AD and PD respectively. The relationship between them could be described in terms of two polynomial equations: AD = 0.94 + 1.31(MD) + 0.02(MD) and PD = 2.21(PSD) 0.05(PSD) 0.006. These nonlinear relationships may be the result of differences in testing method (test stimulus spectrum, number of testing locations or background luminance) or differences in the way each global index was calculated. Conclusion: The AD and PD results obtained from the MAP may be substituted for the MD and PSD of the HFA after an appropriate conversion.
Alok Sharma - One of the best experts on this subject based on the ideXlab platform.
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A comparison of global indices between the Medmont Automated Perimeter and the Humphrey Field Analyzer
2020Co-Authors: John Landers, Alok Sharma, Ivan GoldbergAbstract:Background: Two commonly used Perimeters in Australia are the Humphrey Field Analyzer II (HFA) and the Medmont Automated Perimeter (MAP). Each device describes the visual field in terms of numerical values called global indices; however, these values are not interchangeable between devices. This study was designed to directly compare the global indices of HFA and MAP visual fields. Methods: 63 subjects who had suspected glaucoma, ocular hypertension or glaucoma, or were normal controls were recruited selectively. Each patient was tested with the MAP and HFA. Global indices were then compared between tests. These included mean deviation (MD) and pattern standard deviation (PSD) from the HFA and average defect (AD) and pattern defect (PD) from the MAP. Results: The MD and PSD results were strongly correlated with the AD and PD results, respectively. The relationship between them could be described in terms of two polynomial equations: AD = 0.94+1.31(MD)+0.02(MD) 2 and PD = 2.21(PSD)-0.05(PSD) 2 -0.006. These non-linear relationships may be the result of differences in testing method (test stimulus spectrum, number of testing locations or background luminance) or differences in the way each global index was calculated. Conclusion: The AD and PD results obtained from the MAP may be substituted for the MD and PSD results from the HFA after appropriate conversion
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comparison of visual field sensitivities between the medmont Automated Perimeter and the humphrey field analyser
Clinical and Experimental Ophthalmology, 2010Co-Authors: John Landers, Alok Sharma, Ivan Goldberg, Stuart L GrahamAbstract:Background: Two commonly used Perimeters in Australia and in many parts of Asia are the Humphrey field analyser II (HFA) and the Medmont Automated Perimeter (MAP). Each device maps the incremental light threshold of the visual field and describes the sensitivity at each point in ‘decibels’ (dB); however, these values are not interchangeable between devices. This study was designed to compare directly the sensitivity values of HFA and MAP visual fields. Methods: Sixty-three subjects who had suspected glaucoma, ocular hypertension or glaucoma, or were normal controls were recruited selectively. One eye from each patient was tested with the MAP and HFA in random order on the same day. Corresponding points between the two tests were identified and their sensitivities were compared. Results: Sensitivities between MAP and HFA were strongly correlated (r2 = 0.45; P < 0.0001), with the relationship between them being described by the linear equation: MAP = 0.75*(HFA) − 0.87. On average, across the entire field MAP sensitivities were 7.4 dB (standard deviation 4.6 dB) lower than HFA. However, this relationship was modified by eccentricity and field sensitivity loss. Conclusion: Visual field sensitivities for MAP and HFA may be related by a linear relationship. Theoretical and clinical predictions that this difference may be on average approximately 5 dB have been confirmed.
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a comparison of global indices between the medmont Automated Perimeter and the humphrey field analyzer
British Journal of Ophthalmology, 2007Co-Authors: John A Landers, Alok Sharma, Ivan Goldberg, Stuart L GrahamAbstract:Background: Two commonly used Perimeters in Australia are the Humphrey Field Analyzer II (HFA) and the Medmont Automated Perimeter (MAP). Each device describes the visual field in terms of numerical values called 9global indices9, however these values are not interchangeable between devices. This study was designed to compare directly the global indices of HFA and MAP visual fields. Methods: 63 subjects who were glaucoma suspects, ocular hypertensives, glaucoma patients, or normal controls were recruited selectively. Each patient was tested with the MAP and HFA. Global indices were then compared between tests. These included Mean Deviation (MD) and Pattern Standard Deviation (PSD) from HFA and Average Defect (AD) and Pattern Defect (PD) from MAP. Results: Results of MD and PSD were strongly correlated with those of AD and PD respectively. The relationship between them could be described in terms of two polynomial equations: AD = 0.94 + 1.31(MD) + 0.02(MD) 2 and PD = 2.21(PSD) - 0.05(PSD) 2 - 0.006. These nonlinear relationships may be the result of differences in testing method (test stimulus spectrum, number of testing locations or background luminance) or differences in the way each global index was calculated. Conclusion: The AD and PD results obtained from the MAP may be substituted for the MD and PSD of the HFA after an appropriate conversion.
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a comparison of global indices between the medmont Automated Perimeter and the humphrey field analyzer short running title comparing medmont with humphrey global indices
2007Co-Authors: John A Landers, Alok Sharma, Ivan Goldberg, Stuart L GrahamAbstract:Background: Two commonly used Perimeters in Australia are the Humphrey Field Analyzer II (HFA) and the Medmont Automated Perimeter (MAP). Each device describes the visual field in terms of numerical values called ‘global indices’, however these values are not interchangeable between devices. This study was designed to compare directly the global indices of HFA and MAP visual fields. Methods: 63 subjects who were glaucoma suspects, ocular hypertensives, glaucoma patients, or normal controls were recruited selectively. Each patient was tested with the MAP and HFA. Global indices were then compared between tests. These included Mean Deviation (MD) and Pattern Standard Deviation (PSD) from HFA and Average Defect (AD) and Pattern Defect (PD) from MAP. Results: Results of MD and PSD were strongly correlated with those of AD and PD respectively. The relationship between them could be described in terms of two polynomial equations: AD = 0.94 + 1.31(MD) + 0.02(MD) and PD = 2.21(PSD) 0.05(PSD) 0.006. These nonlinear relationships may be the result of differences in testing method (test stimulus spectrum, number of testing locations or background luminance) or differences in the way each global index was calculated. Conclusion: The AD and PD results obtained from the MAP may be substituted for the MD and PSD of the HFA after an appropriate conversion.
