The Experts below are selected from a list of 441 Experts worldwide ranked by ideXlab platform
Dimitrios Brouzas - One of the best experts on this subject based on the ideXlab platform.
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home based visual field test for glaucoma screening comparison with Humphrey Perimeter
Clinical Ophthalmology, 2018Co-Authors: Stylianos Tsapakis, Dimitrios Papaconstantinou, Andreas Diagourtas, Stylianos A Kandarakis, Konstantinos Droutsas, Konstantinos Andreanos, Dimitrios BrouzasAbstract:Purpose: To present a home-based visual field examination method using a PC monitor or virtual reality glasses and evaluate the reliability of the method by comparing the results with those of the Humphrey Perimeter, in order to assess the possibility of glaucoma screening through the Internet. Materials and methods: Software implementing a supra-threshold algorithm for the central 24° (52 points) of visual field at three threshold levels: 1) -4 db, 2) -8 db, and 3) -12 db, from the age-expected sensitivity was used for the purpose of testing. The software uses the web camera as a "virtual photometer" in order to detect room luminosity and allows self-testing using a computer monitor or virtual reality glasses using an Android smartphone with a 6-inch display. The software includes an expert system to analyze the visual field image and validate the reliability of the results. It also allows the physician to combine the results from two or more tests into a single test in order to achieve higher statistical accuracy of the final result. A total of ten patients, 20 eyes tested×52 points per eye=1,040 visual field test points, were compared point to point to those obtained using the Humphrey Perimeter for the same patients, as they appeared randomly and consecutively at the glaucoma department within hours. Results: Good receiver operating characteristic/area under the curve coefficient was found, ranging from 0.762 to 0.837 (P<0.001). Sensitivity ranged from 0.637 to 0.942, and specificity ranged from 0.735 to 0.497. Conclusion: The home-based visual field test exhibits a reasonable receiver operating characteristic curve when compared to the Humphrey Perimeter, without the need of specialized equipment. The test may be useful for glaucoma screening.
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visual field examination method using virtual reality glasses compared with the Humphrey Perimeter
Clinical Ophthalmology, 2017Co-Authors: Stylianos Tsapakis, Dimitrios Papaconstantinou, Andreas Diagourtas, Konstantinos Droutsas, Konstantinos Andreanos, Marilita M. Moschos, Dimitrios BrouzasAbstract:PURPOSE: To present a visual field examination method using virtual reality glasses and evaluate the reliability of the method by comparing the results with those of the Humphrey Perimeter. MATERIALS AND METHODS: Virtual reality glasses, a smartphone with a 6 inch display, and software that implements a fast-threshold 3 dB step staircase algorithm for the central 24° of visual field (52 points) were used to test 20 eyes of 10 patients, who were tested in a random and consecutive order as they appeared in our glaucoma department. The results were compared with those obtained from the same patients using the Humphrey Perimeter. RESULTS: High correlation coefficient (r=0.808, P<0.0001) was found between the virtual reality visual field test and the Humphrey Perimeter visual field. CONCLUSION: Visual field examination results using virtual reality glasses have a high correlation with the Humphrey Perimeter allowing the method to be suitable for probable clinical use.
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visual field examination using a video projector comparison with Humphrey Perimeter
Clinical Ophthalmology, 2014Co-Authors: Dimitrios Brouzas, Stylianos Tsapakis, Eirini Nitoda, Marilita M. MoschosAbstract:PURPOSE: To present a method of visual field examination using a video projector. Also, we compare our results with those of a Humphrey Perimeter, which is accepted as standard in automated perimetry. MATERIALS AND METHODS: Software implementing a full-threshold 4-2-step staircase algorithm for the central 30-2 of the visual field (76 points) has been developed and tested in nine eyes of seven patients using an Epson TW 700 video projector. The results were compared to those obtained from the same patients using the Humphrey Perimeter. RESULTS: High correlation between the video projector visual fields and those of the Humphrey Perimeter was found. The point-to-point correlation coefficient ranged from 0.75 to 0.90, with P<0.0001 for each eye. CONCLUSION: Visual field examination results using a video projector have high correlation with those of a Humphrey Perimeter. The method is possibly suitable for clinical use.
Stylianos Tsapakis - One of the best experts on this subject based on the ideXlab platform.
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home based visual field test for glaucoma screening comparison with Humphrey Perimeter
Clinical Ophthalmology, 2018Co-Authors: Stylianos Tsapakis, Dimitrios Papaconstantinou, Andreas Diagourtas, Stylianos A Kandarakis, Konstantinos Droutsas, Konstantinos Andreanos, Dimitrios BrouzasAbstract:Purpose: To present a home-based visual field examination method using a PC monitor or virtual reality glasses and evaluate the reliability of the method by comparing the results with those of the Humphrey Perimeter, in order to assess the possibility of glaucoma screening through the Internet. Materials and methods: Software implementing a supra-threshold algorithm for the central 24° (52 points) of visual field at three threshold levels: 1) -4 db, 2) -8 db, and 3) -12 db, from the age-expected sensitivity was used for the purpose of testing. The software uses the web camera as a "virtual photometer" in order to detect room luminosity and allows self-testing using a computer monitor or virtual reality glasses using an Android smartphone with a 6-inch display. The software includes an expert system to analyze the visual field image and validate the reliability of the results. It also allows the physician to combine the results from two or more tests into a single test in order to achieve higher statistical accuracy of the final result. A total of ten patients, 20 eyes tested×52 points per eye=1,040 visual field test points, were compared point to point to those obtained using the Humphrey Perimeter for the same patients, as they appeared randomly and consecutively at the glaucoma department within hours. Results: Good receiver operating characteristic/area under the curve coefficient was found, ranging from 0.762 to 0.837 (P<0.001). Sensitivity ranged from 0.637 to 0.942, and specificity ranged from 0.735 to 0.497. Conclusion: The home-based visual field test exhibits a reasonable receiver operating characteristic curve when compared to the Humphrey Perimeter, without the need of specialized equipment. The test may be useful for glaucoma screening.
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visual field examination method using virtual reality glasses compared with the Humphrey Perimeter
Clinical Ophthalmology, 2017Co-Authors: Stylianos Tsapakis, Dimitrios Papaconstantinou, Andreas Diagourtas, Konstantinos Droutsas, Konstantinos Andreanos, Marilita M. Moschos, Dimitrios BrouzasAbstract:PURPOSE: To present a visual field examination method using virtual reality glasses and evaluate the reliability of the method by comparing the results with those of the Humphrey Perimeter. MATERIALS AND METHODS: Virtual reality glasses, a smartphone with a 6 inch display, and software that implements a fast-threshold 3 dB step staircase algorithm for the central 24° of visual field (52 points) were used to test 20 eyes of 10 patients, who were tested in a random and consecutive order as they appeared in our glaucoma department. The results were compared with those obtained from the same patients using the Humphrey Perimeter. RESULTS: High correlation coefficient (r=0.808, P<0.0001) was found between the virtual reality visual field test and the Humphrey Perimeter visual field. CONCLUSION: Visual field examination results using virtual reality glasses have a high correlation with the Humphrey Perimeter allowing the method to be suitable for probable clinical use.
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visual field examination using a video projector comparison with Humphrey Perimeter
Clinical Ophthalmology, 2014Co-Authors: Dimitrios Brouzas, Stylianos Tsapakis, Eirini Nitoda, Marilita M. MoschosAbstract:PURPOSE: To present a method of visual field examination using a video projector. Also, we compare our results with those of a Humphrey Perimeter, which is accepted as standard in automated perimetry. MATERIALS AND METHODS: Software implementing a full-threshold 4-2-step staircase algorithm for the central 30-2 of the visual field (76 points) has been developed and tested in nine eyes of seven patients using an Epson TW 700 video projector. The results were compared to those obtained from the same patients using the Humphrey Perimeter. RESULTS: High correlation between the video projector visual fields and those of the Humphrey Perimeter was found. The point-to-point correlation coefficient ranged from 0.75 to 0.90, with P<0.0001 for each eye. CONCLUSION: Visual field examination results using a video projector have high correlation with those of a Humphrey Perimeter. The method is possibly suitable for clinical use.
Juhani P Airaksinen - One of the best experts on this subject based on the ideXlab platform.
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nerve fiber layer defects with normal visual fields do normal optic disc and normal visual field indicate absence of glaucomatous abnormality
Ophthalmology, 1993Co-Authors: Anja Tuulonen, Jaana Lehtola, Juhani P AiraksinenAbstract:Purpose: When the optic disc has normal appearance with no abnormalities in routine automated perimetry, the subject is not considered to have glaucoma. The purpose of this study is to show how such patients may have localized retinal nerve fiber layer defects with corresponding functional abnormality. Methods: The authors selected eight eyes of eight patients who had a localized retinal nerve fiber layer defect extending within a few degrees from fovea but in whom the optic disc appearance and Humphrey 30-2 visual fields were normal. Of the eight patients, three had positive family history of glaucoma, two had suspected retinal nerve fiber layer abnormality in routine eye examination, two had increased intraocular pressure (IOP), and one had advanced low-tension glaucoma in one eye with a normal fellow eye. The authors examined the central 10° visual field with 10° resolution using Humphrey Perimeter and the Ring and Centring programs of the high-pass resolution Perimeter. Results: A central field defect corresponding to retinal nerve fiber layer defect was found in six of eight patients: in both 10° Humphrey field and Centring programs (2 eyes), in Humphrey only (2 eyes), and in Centring only (2 eyes). Conclusions: The results indicate that retinal nerve fiber layer photographs are helpful in diagnosing glaucoma because early glaucomatous abnormalities cannot be excluded without nerve fiber layer photography. Currently available routine perimetric examination programs do not always detect very early functional damage.
Marilita M. Moschos - One of the best experts on this subject based on the ideXlab platform.
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visual field examination method using virtual reality glasses compared with the Humphrey Perimeter
Clinical Ophthalmology, 2017Co-Authors: Stylianos Tsapakis, Dimitrios Papaconstantinou, Andreas Diagourtas, Konstantinos Droutsas, Konstantinos Andreanos, Marilita M. Moschos, Dimitrios BrouzasAbstract:PURPOSE: To present a visual field examination method using virtual reality glasses and evaluate the reliability of the method by comparing the results with those of the Humphrey Perimeter. MATERIALS AND METHODS: Virtual reality glasses, a smartphone with a 6 inch display, and software that implements a fast-threshold 3 dB step staircase algorithm for the central 24° of visual field (52 points) were used to test 20 eyes of 10 patients, who were tested in a random and consecutive order as they appeared in our glaucoma department. The results were compared with those obtained from the same patients using the Humphrey Perimeter. RESULTS: High correlation coefficient (r=0.808, P<0.0001) was found between the virtual reality visual field test and the Humphrey Perimeter visual field. CONCLUSION: Visual field examination results using virtual reality glasses have a high correlation with the Humphrey Perimeter allowing the method to be suitable for probable clinical use.
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visual field examination using a video projector comparison with Humphrey Perimeter
Clinical Ophthalmology, 2014Co-Authors: Dimitrios Brouzas, Stylianos Tsapakis, Eirini Nitoda, Marilita M. MoschosAbstract:PURPOSE: To present a method of visual field examination using a video projector. Also, we compare our results with those of a Humphrey Perimeter, which is accepted as standard in automated perimetry. MATERIALS AND METHODS: Software implementing a full-threshold 4-2-step staircase algorithm for the central 30-2 of the visual field (76 points) has been developed and tested in nine eyes of seven patients using an Epson TW 700 video projector. The results were compared to those obtained from the same patients using the Humphrey Perimeter. RESULTS: High correlation between the video projector visual fields and those of the Humphrey Perimeter was found. The point-to-point correlation coefficient ranged from 0.75 to 0.90, with P<0.0001 for each eye. CONCLUSION: Visual field examination results using a video projector have high correlation with those of a Humphrey Perimeter. The method is possibly suitable for clinical use.
Michele Iester - One of the best experts on this subject based on the ideXlab platform.
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clinical ability of heidelberg retinal tomograph examination to detect glaucomatous visual field changes
Ophthalmology, 2001Co-Authors: Stefano Miglior, Marta Casula, M Guareschi, Ilaria Marchetti, Michele Iester, N OrzalesiAbstract:Abstract Purpose To determine the agreement between Heidelberg Retinal Tomograph (HRT; Heidelberg Instruments, Heidelberg, Germany) and visual field examinations in differentiating normal from glaucomatous eyes and to evaluate the sensitivity and specificity of HRT optic disc examination in detecting eyes with glaucomatous damage. Study design Cross-sectional study. Participants Three hundred fifty-nine patients, for a total of 359 eyes (55 normal, 209 with ocular hypertension [OHT], and 95 with primary open-angle glaucoma). Intervention Optic disc imaging by HRT, using a 10° angle view; a mean of three repeated images were analyzed using version 2.01 software. The optic disc was classified as "normal/glaucomatous" on the basis of multivariate discriminant analysis and cumulative frequency distribution (ranked-segment distribution curves). The visual field was examined using the DS 30 II program (Humphrey Perimeter, Zeiss Humphrey System, Dublin, CA), with a glaucomatous visual field being defined on the basis of an abnormal glaucoma hemifield test and a statistically significant corrected pattern standard deviation less than 4 dB. Main outcome measures Agreement between HRT and visual field examinations calculated by means of the κ statistic and the sensitivity and specificity of HRT examination. Results The agreement between the visual field-based and HRT definition of glaucoma was fair to poor, with a κ statistic of between 0.48 and 0.28. The sensitivity and specificity of the HRT examination were, respectively, 80% and 65%, according to Mikelberg's analysis, and, respectively, 31% to 53% and 90% to 92%, according to the analysis based on cumulative curves of normality. Conclusions In a broad clinical setting including normal, OHT, and glaucoma patients, the HRT and visual field tests have fair to poor agreement in detecting glaucoma. The HRT demonstrated a lack of specificity when using Mikelberg's multivariate discriminant analysis and a lack of sensitivity when using cumulative frequency distribution (ranked-segment distribution) curves. These values did not change when normal or OHT patients were excluded from the analysis. In the clinical setting, caution should be used when interpreting HRT results on the basis of multivariate discriminant analysis or cumulative frequency distribution curves.
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the effect of optic disc size on diagnostic precision with the heidelberg retina tomograph
Ophthalmology, 1997Co-Authors: Michele Iester, Frederick S Mikelberg, Stephen M DranceAbstract:Purpose: The authors evaluated the ability of a confocal scanning laser ophthalmoscope to detect glaucomatous visual field loss by using their previously described discriminant formula on a prospectively obtained cohort. The relationship of optic disc size to diagnostic classification was also evaluated. Methods: One eye was chosen randomly from each of 153 subjects. Sixty control eyes had intraocular pressure less than 21 mmHg and normal visual fields; 93 glaucomatous eyes had intraocular pressure greater than 21 mmHg and abnormal visual fields. The optic disc status purposely was not used for classification purposes. All subjects were examined with the Heidelberg Retina Tomograph (HRT; Heidelberg Engineering GMBH, Heidelberg, Germany) and Humphrey Perimeter, program 30-2 (Humphrey Instruments, Inc., San Leandro, CA). Visual fields were considered abnormal by the authors' previously published criteria. The HRT classification used age, adjusted cup shape measure, rim volume, and height variation contour to classify the optic disc as normal or glaucomatous. Then the authors assessed the sensitivity, specificity, and diagnostic precision for the entire group, and for three subsets classified by disc area: disc area less than 2 mm 2 , between 2 and 3 mm 2 , and more than 3 mm 2 . Results: The entire group had a sensitivity, specificity, and diagnostic precision of 74%, 88%, and 80%, respectively. The specificity was 83% when disc area was less than 2 mm 2 and improved to 89% when disc area was more than 2 mm2. The sensitivity tended to improve from 65% to 79%, and to 83% if the disc area increased, but the difference was not statistically significant. Conclusions: In a prospective cohort of patients, the HRT discriminant analysis formula was capable of detecting glaucomatous visual field loss with good precision. Unusually small optic discs continue to present diagnostic difficulties.