Scanning Laser Polarimetry

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Robert N Weinreb - One of the best experts on this subject based on the ideXlab platform.

  • detection of progressive retinal nerve fiber layer loss in glaucoma using Scanning Laser Polarimetry with variable corneal compensation
    Investigative Ophthalmology & Visual Science, 2009
    Co-Authors: Felipe A. Medeiros, Linda M Zangwill, Pamela A Sample, Christopher Bowd, Luciana M Alencar, Gianmarco Vizzeri, Robert N Weinreb
    Abstract:

    Glaucoma is a progressive disease characterized by pathologic loss of ganglion cells and retinal nerve fiber layer with or without associated visual field loss.1 Current management of glaucoma is focused on reducing intraocular pressure, and treatment is considered effective if it is able to slow or halt disease progression. Accurate methods for detecting disease progression are therefore essential to monitor patients and evaluate the efficacy of therapy. Although automated perimetry has been the standard method for detecting progressive disease, it is known that many patients can have progressive structural damage that precedes detectable associated changes in the visual field.2,3 Evaluation of progressive structural damage in glaucoma can be performed by comparing the appearance of the optic disc on longitudinal stereophotographs. This method, however, is limited by the need for subjective evaluation performed by skilled examiners, requirement for pupillary dilation, and may also offer suboptimal evaluation of the retinal nerve fiber layer (RNFL). Several imaging technologies have become available to objectively evaluate the optic disc and the RNFL. One of these technologies, Scanning Laser Polarimetry (SLP), provides quantitative estimates of the thickness of the RNFL with potential use for diagnosis and follow-up of glaucoma patients.4,5 It is based on the principle that polarized light passing through the birefringent RNFL undergoes a measurable phase shift, known as retardation, which is linearly related to histologically measured RNFL tissue thickness.6 The introduction of variable corneal compensation (VCC) in a commercially available Scanning Laser polarimeter (GDx VCC, software version 5.5.1; Carl-Zeiss Meditec, Inc., Dublin, CA) has resulted in improved diagnostic accuracy compared to earlier versions of this technology, which used fixed corneal compensation.7-12 GDx VCC measurements are reproducible13,14 and detect RNFL loss in patients with glaucomatous visual field damage as well as in glaucoma suspects.11,15-18 However, the ability of this technology to monitor progressive RNFL loss in a longitudinal study has not yet been reported. The purpose of this study was to evaluate the ability of the GDx VCC to detect progressive RNFL loss in glaucoma patients and patients suspected of having the disease. We report on the ability of the GDx VCC to detect progressive disease, as well as on the factors influencing longitudinal measurements of the RNFL thickness obtained by this instrument.

  • Scanning Laser Polarimetry demonstration of retinal nerve fiber layer damage in human immunodeficiency virus positive patients without infectious retinitis
    Retina-the Journal of Retinal and Vitreous Diseases, 2007
    Co-Authors: Igor Kozak, Robert N Weinreb, D Bartsch, Lingyun Cheng, Allen Mccutchan, William R Freeman
    Abstract:

    BACKGROUND To use Scanning Laser Polarimetry with variable corneal compensation to measure the retinal nerve fiber layer (RNFL) in human immunodeficiency virus (HIV)-infected patients. METHODS Three groups were analyzed in a prospective cohort study from one center. Group A consisted of 52 eyes of HIV-positive patients whose CD4 cell counts had never fallen below 100/mm (1.0 x 10/L). Group B included 60 eyes of HIV-positive patients with CD4 cell counts that had fallen below 100/mm for at least 6 months in their history. Group C consisted of 50 eyes of HIV-negative patients. None of the eyes had a history of infectious retinitis. Retinal birefringence imaging studies were performed using a commercially available Scanning Laser. Superior, inferior, and ellipse averages as well as nerve fiber indicator parameters were used for comparison. RESULTS Group B significantly differed from group C in all parameters. Group B also differed from group A in all parameters with the exception of superior average. No difference was detected between group A and group C. CONCLUSION Scanning Laser Polarimetry demonstrated RNFL thinning in HIV-positive patients without retinitis who had a history of low CD4 cell counts compared with HIV-positive subjects with high CD4 cell counts and HIV-negative patients.

  • retinal nerve fiber layer thickness and visual sensitivity using Scanning Laser Polarimetry with variable and enhanced corneal compensation
    Ophthalmology, 2007
    Co-Authors: Christopher Bowd, Linda M Zangwill, Pamela A Sample, Felipe A. Medeiros, Ivan Maynart Tavares, Robert N Weinreb
    Abstract:

    Purpose To compare the strength of the structure–function association between Scanning Laser Polarimetry-measured retinal nerve fiber layer (RNFL) thickness and visual sensitivity. Two methods of corneal compensation were evaluated, variable corneal compensation (VCC) and enhanced corneal compensation (ECC). Design Observational case series. Participants One hundred twenty-seven glaucoma (repeatable abnormal visual fields [VF] by pattern standard deviation and/or glaucoma hemifield test) or glaucoma suspect (glaucomatous-appearing discs by photograph assessment without field defects) participants in the University of California, San Diego Diagnostic Innovations in Glaucoma Study. Methods One eye of each participant was imaged using GDx VCC and GDx ECC on the same day. Visual fields tested using the Humphrey Field Analyzer (with Swedish interactive threshold algorithm) were obtained within 6 months of imaging. Main Outcome Measure The associations ( R 2 ) using linear and logarithmic regression between RNFL thicknesses measured in 6 sectors (inferior, inferotemporal, temporal, superotemporal, superior, nasal) with VCC and ECC and VF sensitivities (decibel threshold measurements) measured in 6 corresponding sectors were compared. Comparisons were made using paired t tests on the log-transformed absolute values of regression residuals. Results Using GDx VCC, 32 scans had a typical scan score (TSS) ≤ 78 (lowest quartile) and no ECC scans had TSS R 2 ) ranged from 0.03 (temporal RNFL) to 0.22 (superotemporal RNFL) for VCC and from 0.01 (temporal RNFL) to 0.26 (superotemporal RNFL) for ECC. Associations generally were slightly stronger for ECC than for VCC, although these differences were only significant for inferotemporal RNFL ( R 2 = 0.19 and 0.11, for ECC and VCC, respectively). Conclusion The RNFL thickness associations with VF sensitivity are stronger using ECC compared with VCC, suggesting that ECC provides a better cross-sectional representation of visual function than VCC.

  • combining structural and functional testing for detection of glaucoma
    Ophthalmology, 2006
    Co-Authors: Neha Shah, Robert N Weinreb, Pamela A Sample, Christopher Bowd, Felipe A. Medeiros, Esther M Hoffmann, Linda M Zangwill
    Abstract:

    Purpose To assess whether the combined use of both structural and functional tests improves discrimination between healthy and glaucomatous eyes over either type of testing alone. Design Observational cross-sectional study. Participants One hundred twenty-three eyes of 123 participants enrolled in the Diagnostic Innovations in Glaucoma Study. Methods Because both structural and functional tests were evaluated, 2 definitions of glaucoma were used: glaucomatous visual field (VF) damage based on repeatable abnormal standard automated perimetry results (n = 43) and glaucomatous optic disc (glaucomatous optic neuropathy [GON]) based on masked assessment of optic disc stereophotographs (n = 65). Participants had Scanning Laser Polarimetry, optical coherence tomography (OCT), and confocal Scanning Laser ophthalmoscopy imaging in addition to frequency-doubling technology (FDT) perimetry and short-wavelength automated perimetry (SWAP) testing completed within a 6-month interval. Main Outcome Measures For each glaucoma definition, sensitivities and specificities were calculated for the best structural parameters, FDT perimetry pattern standard deviation (PSD), and SWAP PSD/glaucoma hemifield test, and then for each possible pairwise combination of one structural and one functional parameter. Results The best structural parameters for discriminating between glaucoma and control eyes were nerve fiber indicator for Scanning Laser Polarimetry, inferior average retinal nerve fiber layer thickness for OCT, and Moorfields regression classification for confocal Scanning Laser ophthalmoscopy. Sensitivities and specificities for detecting glaucomatous VF damage for Scanning Laser Polarimetry, OCT, confocal Scanning Laser ophthalmoscopy, FDT perimetry, and SWAP were 41.9% and 98.3%, 58.1% and 98.3%, 58.1% and 84.5%, 44.2% and 98.3%, and 65.1% and 86.2%, respectively. Adding FDT perimetry to each of the best structural parameters led to a significant ( P Conclusions A combination of parameters from structural tests and functional tests can improve the sensitivity of glaucoma detection. The sensitivity and specificity desired for a particular clinical application will determine the selection of the particular diagnostic tests.

  • structure function relationships using confocal Scanning Laser ophthalmoscopy optical coherence tomography and Scanning Laser Polarimetry
    Investigative Ophthalmology & Visual Science, 2006
    Co-Authors: Christopher Bowd, Linda M Zangwill, Pamela A Sample, Felipe A. Medeiros, Esther M Hoffmann, Ivan Maynart Tavares, Rupert R A Bourne, Robert N Weinreb
    Abstract:

    PURPOSE. To assess the strength of the association between retinal nerve fiber layer (RNFL) thickness and optic disc topography measured with confocal retinal tomography (HRT II; Heidelberg Engineering, Dossenheim, Germany), optical coherence tomography (StratusOCT; Carl Zeiss Meditec, Inc., Dublin, CA), and Scanning Laser Polarimetry (GDx with variable corneal compensator, VCC; Carl Zeiss Meditec, Inc.), and visual field (VF) sensitivity and to determine whether this association is better expressed as a linear or nonlinear function. METHODS. One hundred twenty-seven patients with glaucoma or suspected glaucoma and 127 healthy eyes from enrollees in the Diagnostic Innovations in Glaucoma Study (DIGS) were tested on HRT II, StratusOCT, GDx VCC, and standard automated perimetry (SAP, with the Swedish Interactive Thresholding Algorithm [SITA]) within 3 months of each other. Linear and logarithmic associations between RNFL thickness (HRT II, StratusOCT, and GDx VCC) and neuroretinal rim area (HRT II) and SAP sensitivity expressed in decibels were determined globally and for six RNFL/optic disc regions (inferonasal, inferotemporal, temporal, superotemporal, superonasal, and nasal) and six corresponding VF regions (superior, superonasal, nasal, inferonasal, inferior, and temporal). RESULTS. The associations (R 2 ) between global and regional RNFL/optic disc measurements and VF sensitivity ranged from <0.01 (temporal RNFL, nasal VF, and nasal RNFL, temporal VF; linear and logarithmic associations) to 0.26 (inferotemporal RNFL, superonasal VF; logarithmic association) for HRT II; from 0.02 (temporal RNFL, nasal VF; linear association) to 0.38 (inferotemporal RNFL, superonasal VF; logarithmic association) for OCT; and from 0.03 (temporal RNFL, nasal VF; linear association) to 0.21 (inferotemporal RNFL, superonasal VF; logarithmic association) for GDx. Structure-function relationships generally were strongest between the inferotemporal RNFL- optic disc sector and the superonasal visual field and were significantly stronger for StratusOCT RNFL thickness than for other instruments in this region. Global associations (linear and logarithmic) were significantly stronger using OCT compared with HRT. In most cases, logarithmic fits were not significantly better than linear fits when visual sensitivity was expressed in log units (i.e., decibels). CONCLUSIONS. These results suggest that structure-function associations are strongest with StratusOCT measurements and are similar between HRT II and GDx VCC and these associations are generally no better expressed logarithmically than linearly when healthy, suspect, and glaucomatous eyes are considered.

Linda M Zangwill - One of the best experts on this subject based on the ideXlab platform.

  • detection of progressive retinal nerve fiber layer loss in glaucoma using Scanning Laser Polarimetry with variable corneal compensation
    Investigative Ophthalmology & Visual Science, 2009
    Co-Authors: Felipe A. Medeiros, Linda M Zangwill, Pamela A Sample, Christopher Bowd, Luciana M Alencar, Gianmarco Vizzeri, Robert N Weinreb
    Abstract:

    Glaucoma is a progressive disease characterized by pathologic loss of ganglion cells and retinal nerve fiber layer with or without associated visual field loss.1 Current management of glaucoma is focused on reducing intraocular pressure, and treatment is considered effective if it is able to slow or halt disease progression. Accurate methods for detecting disease progression are therefore essential to monitor patients and evaluate the efficacy of therapy. Although automated perimetry has been the standard method for detecting progressive disease, it is known that many patients can have progressive structural damage that precedes detectable associated changes in the visual field.2,3 Evaluation of progressive structural damage in glaucoma can be performed by comparing the appearance of the optic disc on longitudinal stereophotographs. This method, however, is limited by the need for subjective evaluation performed by skilled examiners, requirement for pupillary dilation, and may also offer suboptimal evaluation of the retinal nerve fiber layer (RNFL). Several imaging technologies have become available to objectively evaluate the optic disc and the RNFL. One of these technologies, Scanning Laser Polarimetry (SLP), provides quantitative estimates of the thickness of the RNFL with potential use for diagnosis and follow-up of glaucoma patients.4,5 It is based on the principle that polarized light passing through the birefringent RNFL undergoes a measurable phase shift, known as retardation, which is linearly related to histologically measured RNFL tissue thickness.6 The introduction of variable corneal compensation (VCC) in a commercially available Scanning Laser polarimeter (GDx VCC, software version 5.5.1; Carl-Zeiss Meditec, Inc., Dublin, CA) has resulted in improved diagnostic accuracy compared to earlier versions of this technology, which used fixed corneal compensation.7-12 GDx VCC measurements are reproducible13,14 and detect RNFL loss in patients with glaucomatous visual field damage as well as in glaucoma suspects.11,15-18 However, the ability of this technology to monitor progressive RNFL loss in a longitudinal study has not yet been reported. The purpose of this study was to evaluate the ability of the GDx VCC to detect progressive RNFL loss in glaucoma patients and patients suspected of having the disease. We report on the ability of the GDx VCC to detect progressive disease, as well as on the factors influencing longitudinal measurements of the RNFL thickness obtained by this instrument.

  • retinal nerve fiber layer thickness and visual sensitivity using Scanning Laser Polarimetry with variable and enhanced corneal compensation
    Ophthalmology, 2007
    Co-Authors: Christopher Bowd, Linda M Zangwill, Pamela A Sample, Felipe A. Medeiros, Ivan Maynart Tavares, Robert N Weinreb
    Abstract:

    Purpose To compare the strength of the structure–function association between Scanning Laser Polarimetry-measured retinal nerve fiber layer (RNFL) thickness and visual sensitivity. Two methods of corneal compensation were evaluated, variable corneal compensation (VCC) and enhanced corneal compensation (ECC). Design Observational case series. Participants One hundred twenty-seven glaucoma (repeatable abnormal visual fields [VF] by pattern standard deviation and/or glaucoma hemifield test) or glaucoma suspect (glaucomatous-appearing discs by photograph assessment without field defects) participants in the University of California, San Diego Diagnostic Innovations in Glaucoma Study. Methods One eye of each participant was imaged using GDx VCC and GDx ECC on the same day. Visual fields tested using the Humphrey Field Analyzer (with Swedish interactive threshold algorithm) were obtained within 6 months of imaging. Main Outcome Measure The associations ( R 2 ) using linear and logarithmic regression between RNFL thicknesses measured in 6 sectors (inferior, inferotemporal, temporal, superotemporal, superior, nasal) with VCC and ECC and VF sensitivities (decibel threshold measurements) measured in 6 corresponding sectors were compared. Comparisons were made using paired t tests on the log-transformed absolute values of regression residuals. Results Using GDx VCC, 32 scans had a typical scan score (TSS) ≤ 78 (lowest quartile) and no ECC scans had TSS R 2 ) ranged from 0.03 (temporal RNFL) to 0.22 (superotemporal RNFL) for VCC and from 0.01 (temporal RNFL) to 0.26 (superotemporal RNFL) for ECC. Associations generally were slightly stronger for ECC than for VCC, although these differences were only significant for inferotemporal RNFL ( R 2 = 0.19 and 0.11, for ECC and VCC, respectively). Conclusion The RNFL thickness associations with VF sensitivity are stronger using ECC compared with VCC, suggesting that ECC provides a better cross-sectional representation of visual function than VCC.

  • combining structural and functional testing for detection of glaucoma
    Ophthalmology, 2006
    Co-Authors: Neha Shah, Robert N Weinreb, Pamela A Sample, Christopher Bowd, Felipe A. Medeiros, Esther M Hoffmann, Linda M Zangwill
    Abstract:

    Purpose To assess whether the combined use of both structural and functional tests improves discrimination between healthy and glaucomatous eyes over either type of testing alone. Design Observational cross-sectional study. Participants One hundred twenty-three eyes of 123 participants enrolled in the Diagnostic Innovations in Glaucoma Study. Methods Because both structural and functional tests were evaluated, 2 definitions of glaucoma were used: glaucomatous visual field (VF) damage based on repeatable abnormal standard automated perimetry results (n = 43) and glaucomatous optic disc (glaucomatous optic neuropathy [GON]) based on masked assessment of optic disc stereophotographs (n = 65). Participants had Scanning Laser Polarimetry, optical coherence tomography (OCT), and confocal Scanning Laser ophthalmoscopy imaging in addition to frequency-doubling technology (FDT) perimetry and short-wavelength automated perimetry (SWAP) testing completed within a 6-month interval. Main Outcome Measures For each glaucoma definition, sensitivities and specificities were calculated for the best structural parameters, FDT perimetry pattern standard deviation (PSD), and SWAP PSD/glaucoma hemifield test, and then for each possible pairwise combination of one structural and one functional parameter. Results The best structural parameters for discriminating between glaucoma and control eyes were nerve fiber indicator for Scanning Laser Polarimetry, inferior average retinal nerve fiber layer thickness for OCT, and Moorfields regression classification for confocal Scanning Laser ophthalmoscopy. Sensitivities and specificities for detecting glaucomatous VF damage for Scanning Laser Polarimetry, OCT, confocal Scanning Laser ophthalmoscopy, FDT perimetry, and SWAP were 41.9% and 98.3%, 58.1% and 98.3%, 58.1% and 84.5%, 44.2% and 98.3%, and 65.1% and 86.2%, respectively. Adding FDT perimetry to each of the best structural parameters led to a significant ( P Conclusions A combination of parameters from structural tests and functional tests can improve the sensitivity of glaucoma detection. The sensitivity and specificity desired for a particular clinical application will determine the selection of the particular diagnostic tests.

  • structure function relationships using confocal Scanning Laser ophthalmoscopy optical coherence tomography and Scanning Laser Polarimetry
    Investigative Ophthalmology & Visual Science, 2006
    Co-Authors: Christopher Bowd, Linda M Zangwill, Pamela A Sample, Felipe A. Medeiros, Esther M Hoffmann, Ivan Maynart Tavares, Rupert R A Bourne, Robert N Weinreb
    Abstract:

    PURPOSE. To assess the strength of the association between retinal nerve fiber layer (RNFL) thickness and optic disc topography measured with confocal retinal tomography (HRT II; Heidelberg Engineering, Dossenheim, Germany), optical coherence tomography (StratusOCT; Carl Zeiss Meditec, Inc., Dublin, CA), and Scanning Laser Polarimetry (GDx with variable corneal compensator, VCC; Carl Zeiss Meditec, Inc.), and visual field (VF) sensitivity and to determine whether this association is better expressed as a linear or nonlinear function. METHODS. One hundred twenty-seven patients with glaucoma or suspected glaucoma and 127 healthy eyes from enrollees in the Diagnostic Innovations in Glaucoma Study (DIGS) were tested on HRT II, StratusOCT, GDx VCC, and standard automated perimetry (SAP, with the Swedish Interactive Thresholding Algorithm [SITA]) within 3 months of each other. Linear and logarithmic associations between RNFL thickness (HRT II, StratusOCT, and GDx VCC) and neuroretinal rim area (HRT II) and SAP sensitivity expressed in decibels were determined globally and for six RNFL/optic disc regions (inferonasal, inferotemporal, temporal, superotemporal, superonasal, and nasal) and six corresponding VF regions (superior, superonasal, nasal, inferonasal, inferior, and temporal). RESULTS. The associations (R 2 ) between global and regional RNFL/optic disc measurements and VF sensitivity ranged from <0.01 (temporal RNFL, nasal VF, and nasal RNFL, temporal VF; linear and logarithmic associations) to 0.26 (inferotemporal RNFL, superonasal VF; logarithmic association) for HRT II; from 0.02 (temporal RNFL, nasal VF; linear association) to 0.38 (inferotemporal RNFL, superonasal VF; logarithmic association) for OCT; and from 0.03 (temporal RNFL, nasal VF; linear association) to 0.21 (inferotemporal RNFL, superonasal VF; logarithmic association) for GDx. Structure-function relationships generally were strongest between the inferotemporal RNFL- optic disc sector and the superonasal visual field and were significantly stronger for StratusOCT RNFL thickness than for other instruments in this region. Global associations (linear and logarithmic) were significantly stronger using OCT compared with HRT. In most cases, logarithmic fits were not significantly better than linear fits when visual sensitivity was expressed in log units (i.e., decibels). CONCLUSIONS. These results suggest that structure-function associations are strongest with StratusOCT measurements and are similar between HRT II and GDx VCC and these associations are generally no better expressed logarithmically than linearly when healthy, suspect, and glaucomatous eyes are considered.

  • retinal nerve fiber layer thickness measurements with Scanning Laser Polarimetry predict glaucomatous visual field loss
    American Journal of Ophthalmology, 2004
    Co-Authors: Kourosh Mohammadi, Robert N Weinreb, Pamela A Sample, Christopher Bowd, Felipe A. Medeiros, Linda M Zangwill
    Abstract:

    Purpose To assess whether baseline retinal nerve fiber layer (RNFL) measurements obtained with a Scanning Laser polarimeter, the GDx Nerve Fiber Analyzer, (Laser Diagnostic Technologies Inc., San Diego, California) are predictive of development of repeatable glaucomatous visual field damage in glaucoma suspect eyes. Design Cohort study. Methods Participants were recruited from the UCSD longitudinal Diagnostic Innovations in Glaucoma Study (DIGS). One eye from each of 160 glaucoma suspects with normal standard automated perimetry (SAP) visual fields at baseline was studied. Study eyes were divided into convert and nonconvert groups based on the development of three consecutive glaucomatous visual fields during follow-up. SLP parameters, IOP, vertical cup disk ratio, stereophotograph assessment as glaucoma or normal, corneal thickness, and visual field indices were included in univariate and multivariate Cox proportional hazards models to determine which SLP RNFL and ocular parameters were predictive of visual field conversion. Results Sixteen (10%) eyes developed repeatable visual field damage (converts) and 144 (90%) did not (nonconverts). Mean (95%CI) follow-up time until visual field conversion for convert eyes was 2.7 (1.7, 3.6) years. Mean total follow-up of nonconvert eyes was 3.8 (3.5, 4.1) years. Four out of thirteen examined baseline SLP parameters and baseline SAP Mean Deviation (MD), SAP Pattern Standard Deviation (PSD), and glaucomatous stereophotograph assessment were significant univariate predictors of visual field conversion. In multivariate models adjusted for age, IOP and CCT, SLP parameters inferior ratio, ellipse modulation, and UCSD linear discriminant function (LDF) were significant predictors of visual field conversion. When SAP PSD and stereophotograph assessment were also included in the multivariate model inferior ratio and UCSD LDF remained independently predictive of visual field loss. Conclusions Thinner baseline SLP RNFL measurements were independent predictors of visual field damage. In addition to thinner SLP RNFL measurements, higher baseline SAP PSD, and baseline glaucomatous stereophotograph assessment each contributed to an increased risk of the development of abnormal visual fields in glaucoma suspect patients. SLP RNFL measurements were independently predictive of future visual loss even when age, IOP, CCT, vertical cup disk ratio, and SAP PSD were included in the model.

Costa V.p. - One of the best experts on this subject based on the ideXlab platform.

  • Discrimination Between Normal And Glaucomatous Eyes By Scanning Laser Polarimetry [discriminação Entre Olhos Normais E Glaucomatosos Mediante Polarimetria De Varredura A Laser]
    2015
    Co-Authors: Magacho L., Marcondes A.m., Costa V.p.
    Abstract:

    Purpose: To test the ability of the Scanning Laser Polarimetry to discriminate between normal and glaucomatous eyes. Methods: One-hundred and twelve patients with primary open-angle glaucoma and 88 normal individuals were enrolled in the study. All individuals underwent a complete ophthalmic evaluation, a 24-2 full threshold Humphrey visual field and a GDx examination. Cutoff points were selected, ROC curves were created, and the sensitivity (Se) and specificity (Sp) were calculated for each individual GDx parameter. Finally, a multivariate logistic analysis was developed in order to achieve a better Se/Sp ratio for the diagnosis of glaucoma. Results: The best GDx individual parameters were: the number (Se: 79.5%%, Sp: 81.8%, area under the ROC curve: 0.870), maximum modulation (Se: 83.0%, Sp: 76.1%, area under the ROC curve: 0.842) and ellipse modulation (Se: 65.2%, Sp: 88.6%). The multivariate logistic analysis resulted in an area under the ROC curve of 0.920 (Se: 85.7%, Sp: 90.9%). Conclusions: The combination of 2 or more parameters in a multivariate logistic analysis increases the ability of Scanning Laser Polarimetry to discriminate between normal and glaucomatous eyes

  • Discrimination Between Normal And Glaucomatous Eyes By Scanning Laser Polarimetry [discriminação Entre Olhos Normais E Glaucomatosos Mediante Polarimetria De Varredura A Laser]
    2015
    Co-Authors: Magacho L., Marcondes A.m., Costa V.p.
    Abstract:

    Purpose: To test the ability of the Scanning Laser Polarimetry to discriminate between normal and glaucomatous eyes. Methods: One-hundred and twelve patients with primary open-angle glaucoma and 88 normal individuals were enrolled in the study. All individuals underwent a complete ophthalmic evaluation, a 24-2 full threshold Humphrey visual field and a GDx examination. Cutoff points were selected, ROC curves were created, and the sensitivity (Se) and specificity (Sp) were calculated for each individual GDx parameter. Finally, a multivariate logistic analysis was developed in order to achieve a better Se/Sp ratio for the diagnosis of glaucoma. Results: The best GDx individual parameters were: the number (Se: 79.5%%, Sp: 81.8%, area under the ROC curve: 0.870), maximum modulation (Se: 83.0%, Sp: 76.1%, area under the ROC curve: 0.842) and ellipse modulation (Se: 65.2%, Sp: 88.6%). The multivariate logistic analysis resulted in an area under the ROC curve of 0.920 (Se: 85.7%, Sp: 90.9%). Conclusions: The combination of 2 or more parameters in a multivariate logistic analysis increases the ability of Scanning Laser Polarimetry to discriminate between normal and glaucomatous eyes.672249254Kerrigan-Baumrind, L.A., Quigley, H.A., Pease, M.E., Kerrigan, D.F., Mitchell, R.S., Number of ganglion cells in glaucoma eyes compared with threshold visual field tests in the same persons (2000) Invest Ophthalmol Vis Sci, 41, pp. 741-748Quigley, H.A., Addicks, E.M., Green, W.R., Optic nerve damage in human glaucoma. III. Quantitative correlation of nerve fiber loss and visual field defect in glaucoma, ischemic neuropathy, papilledema, and toxic neuropathy (1982) Arch Ophthalmol, 100, pp. 135-146Sommer, A., Katz, J., Quigley, H.A., Miller, N.R., Robin, A.L., Richter, R.C., Witt, K.A., Clinically detectable nerve fiber atrophy precedes the onset of glaucomatous field loss (1991) Arch Ophthalmol, 109, pp. 77-83Quigley, H.A., Katz, J., Derick, R.J., Gilbert, D., Sommer, A., An evaluation of optic disc and nerve fiber layer examinations in monitoring progression of early glaucoma damage (1992) Ophthalmology, 99, pp. 19-28Weinreb, R.N., Shakiba, S., Zangwill, L., Scanning Laser Polarimetry to measure the nerve fiber layer of normal and glaucomatous eyes (1995) Am J Ophthalmol, 119, pp. 627-636Weinreb, R.N., Zangwill, L., Berry, C.C., Bathija, R., Sample, P.A., Detection of glaucoma with Scanning Laser Polarimetry (1998) Arch Ophthalmol, 116, pp. 1583-1589Lauande-Pimentel, R., Carvalho, R.A., Oliveira, H.C., Gonçalves, D.C., Silva, L.M., Costa, V.P., Discrimination between normal and glaucomatous eyes with visual field and Scanning Laser Polarimetry measurements (2001) Br J Ophthalmol, 85, pp. 586-591Choplin, N.T., Lundy, D.C., The sensitivity and specificity of Scanning Laser Polarimetry in the detection of glaucoma in a clinical setting (2001) Ophthalmology, 108, pp. 899-904Kamal, D.S., Bunce, C., Hitchings, R.A., Use of the GDx to detect differences in retinal nerve fiber layer thickness between normal, ocular hypertensive and early glaucomatous eyes (2000) Eye, 14 (PT. 3A), pp. 367-370Colen, T.P., Tjon-Fo-sang, M.J., Mulder, P.G., Lemij, H.G., Reproducibility of measurements with the nerve fiber analyzer (NfA/GDx) (2000) J Glaucoma, 9, pp. 363-370Almeida, P.B., Almeida, G.V., Cohen, R., Prata Júnior, J.A., Melo, P.A.A., Correlação e correspondência topográfica entre espessura da camada de fibras nervosas da retina e campo visual no glaucoma primário de ângulo aberto (2001) Arq Bras Oftalmol, 64, pp. 109-115Weinreb, R.N., Shakiba, S., Sample, P.A., Shahrokni, S., Van Horn, S., Garden, V.S., Association between quantitative nerve fiber layer measurement and visual field loss in glaucoma (1995) Am J Ophthalmol, 120, pp. 732-738Caprioli, J., Discrimination between normal and glaucomatous eyes (1992) Invest Ophthalmol Vis Sci, 33, pp. 153-159Anderson, D.R., Patella, V.M., (1999) Automated Static Perimetry, , St. Louis: Year Book MosbyChylack Jr., L.T., Wolfe, J.K., Singer, D.M., Leske, M.C., Bullimore, M.A., Bailey, I.L., The lens opacities classification system III (1993) The Longitudinal Study of Cataract Study Group. Arch Ophthalmol, 111, pp. 831-836Hodapp, E., Parrish, I.I.R.K., Anderson, D.R., (1993) Clinical Decisions in Glaucoma, , St. Louis: Year Book;Lauande-Pimentel, R., Costa, V.P., Análise da camada de fibras nervosas da retina (2001) Um Guia Para Interpretar o Exame de Polarimetria, , Rio de Janeiro: Cultura Médica;Cross, E.M., Chaffin, W.W., Use of the binomial theorem in interpreting results of multiple tests of significance (1982) Educat Psychol Measure, 42, pp. 25-34Zangwill, L.M., Bowd, C., Berry, C.C., Williams, J., Blumenthal, E.Z., Sanchez-Galeana, C.A., Discriminating between normal and glaucomatous eyes using the Heidelberg retina tomograph, GDx nerve fiber analyzer, and optical coherence tomograph (2001) Arch Ophthalmol, 119, pp. 985-993Greaney, M.J., Hoffman, D.C., Garway-Heath, D.F., Nakla, M., Coleman, A.L., Caprioli, J., Comparison of optic nerve imaging methods to distinguish normal eyes from those with glaucoma (2002) Invest Ophthalmol Vis Sci, 43, pp. 140-145Garway-Heath, D.F., Hitchings, R.A., Sources of bias in studies of optic disc and retinal nerve fiber layer morphology (1998) Br J Ophthalmol, 82, p. 98

  • The Influence Of Intraocular Pressure Reduction With Medication On Retinal Nerve Fiber Layer Thickness Measurements Obtained With Scanning Laser Polarimetry In Glaucomatous And Hypertensive Eyes [influência Da Redução Medicamentosa Da Pressão Intra-ocular Na Medida Da Espessura Da Camada De Fibras Nervosas Da Retina De Olhos Hipertensos E Glaucomatosos Pela Polarimetria De Varredura A Laser]
    2015
    Co-Authors: Avelino R.r.g., Luis P.a.h., Medeiros M., Costa V.p.
    Abstract:

    Purpose: To evaluate changes in retinal nerve fiber layer thickness as measured by Scanning Laser Polarimetry (SLP) after the use of medication to reduce intraocular pressure (IOP) in glaucomatous or ocular hypertensive patients. Methods: The authors prospectively enrolled 37 eyes of 37 patients in whom IOP was reduced by more than 25% after the use of medication. The images were obtained before and 15 to 30 days after the introduction of medication. The SLP parameters measured before and after the use of medication were compared using paired Student's t Test. Results: The mean IOP was significantly reduced from 26.57±4.23 mmHg to 16.54 ±2.92 mmHg after the use of medication (p0.05). Conclusion: The retinal nerve fiber layer thickness, as measured by SLP, is not affected by the reduction of IOP with medication in patients with glaucoma or ocular hypertension

  • The Influence Of Intraocular Pressure Reduction With Medication On Retinal Nerve Fiber Layer Thickness Measurements Obtained With Scanning Laser Polarimetry In Glaucomatous And Hypertensive Eyes [influência Da Redução Medicamentosa Da Pressão Intra-ocular Na Medida Da Espessura Da Camada De Fibras Nervosas Da Retina De Olhos Hipertensos E Glaucomatosos Pela Polarimetria De Varredura A Laser]
    2015
    Co-Authors: Avelino R.r.g., Luis P.a.h., Medeiros M., Costa V.p.
    Abstract:

    Purpose: To evaluate changes in retinal nerve fiber layer thickness as measured by Scanning Laser Polarimetry (SLP) after the use of medication to reduce intraocular pressure (IOP) in glaucomatous or ocular hypertensive patients. Methods: The authors prospectively enrolled 37 eyes of 37 patients in whom IOP was reduced by more than 25% after the use of medication. The images were obtained before and 15 to 30 days after the introduction of medication. The SLP parameters measured before and after the use of medication were compared using paired Student's t Test. Results: The mean IOP was significantly reduced from 26.57±4.23 mmHg to 16.54 ±2.92 mmHg after the use of medication (p0.05). Conclusion: The retinal nerve fiber layer thickness, as measured by SLP, is not affected by the reduction of IOP with medication in patients with glaucoma or ocular hypertension.695655659Glaucoma Primário de Ângulo Aberto 1° Consenso da Sociedade Brasileira de Glaucoma (2001), 1, p. 54. , São Paulo: BG CulturalQuigley, H.A., Addicks, E.M., Green, W.R., Optic nerve damage in human glaucoma. III. Quantitative correlation of nerve fiber loss and visual field defect in glaucoma, ischemic neuropathy, papilledema, and toxic neuropathy (1982) Arch Ophthalmol, 100 (1), pp. 135-146Kahn, H.A., Leibowitz, H., Ganley, J.P., Kini, M., Colton, T., Nickerson, R., Dawber, T.R., Randomized controlled clinical trial. National Eye Institute workshop for ophthalmologists. Standardizing diagnostic procedures (1975) Am J Ophthalmol, 79 (5), pp. 768-775Lichter, P.R., Variability of expert observers in evaluating the optic disc (1976) Trans Am Ophthalmol Soc, 74, pp. 532-572Weinreb, R.N., Dreher, A.W., Coleman, A., Quigley, H., Shaw, B., Reiter, K., Histopathologic validation of Fourier-ellipsometry measurements of optic nerve topography in glaucoma (1998) Invest Ophthalmol Vis Sci, 29, pp. 1294-1298Kamal, D.S., Bunce, C., Hitchings, R.A., Use of the GDx to detect differences in retinal nerve fibre layer thickness between normal, ocular hypertensive and early glaucomatous eyes (2000) Eye, 14 (PART 3A), pp. 367-370Hollo, G., Szabo, A., Vargha, P., Scanning Laser Polarimetry versus frequency - Doubling perimetry and conventional threshold perimetry: Changes during a 12-month follow-up in preperimetric glaucoma. A pilot study (2001) Acta Ophthalmol Scand, 79 (4), pp. 403-407Tezel, G., Siegmund, K.D., Trinkaus, K., Wax, M.B., Kass, M.A., Kolker, A.E., Clinical factors associated with progression of glaucomatous optic disc damage in treated patients (2001) Arch Ophthalmol, 119 (6), pp. 813-818Bowd, C., Weinreb, R.N., Lee, B., Emdadi, A., Zangwill, L.M., Optic disk topography after medical treatment to reduce intraocular pressure (2000) Am J Ophthalmol, 130 (3), pp. 280-286Chylack Jr., L.T., Wolfe, J.K., Singer, D.M., Leske, M.C., Bullimore, M.A., Bailey, I.L., The Lens Opacities Classification System III (1993) Arch Ophthalmol, 111 (6), pp. 831-836. , The Longitudinal Study of Cataract Study GroupZangwill, L.M., Bowd, C., Berry, C.C., Williams, J., Blumenthal, E.Z., Sanchez-Galeana, C.A., Discriminating between normal and glaucomatous eyes using the Heidelberg Retina Tomograph, GDx Nerve Fiber Analyzer, and Optical Coherence Tomograph (2001) Arch Ophthalmol, 119 (7), pp. 985-993Raitta, C., Tomita, G., Vesti, E., Harju, M., Nakao, H., Optic disc topography before and after trabeculectomy in advanced glaucoma (1996) Ophthalmic Surg Lasers, 27 (5), pp. 349-354Yoshikawa, K., Inoue, Y., Changes in optic disc parameters after intraocular pressure reduction in adult glaucoma patients (1999) Jpn J Ophthalmol, 43 (3), pp. 225-231Lee, B.L., Zangwill, L., Weinreb, R.B., Change in optic disc topography associated with diurnal variation in intraocular pressure (1999) J Glaucoma, 8 (3), pp. 221-223Park, K.H., Kim, D.M., Youn, D.H., Short-term change of optic time head topography after trabeculectomy in adult glaucoma patients as measured by Heidelberg retina tomograph (1997) Korean J Ophthalmol, 11 (1), pp. 1-6Lesk, M.R., Spaeth, G.L., Azuara-Blanco, A., Araujo, S.V., Katz, L.J., Terebuh, A.K., Reversal of optic disc cupping after glaucoma surgery analyzed with a Scanning Laser tomograph (1999) Ophthalmology, 106 (5), pp. 1013-1018Kotecha, A., Siriwardena, D., Fitzke, F.W., Hitchings, R.A., Khaw, P.T., Optic disc changes following trabeculectomy: Longitudinal and localization of change (2001) Br J Ophthalmol, 85 (8), pp. 956-961Topouzis, F., Peng, F., Kotas-Neumann, R., Garcia, R., Sanguinet, J., Yu, F., Coleman, A.L., Longitudinal changes in the optic disc topography of adult patients after trabeculectomy (1999) Ophthalmology, 106 (6), pp. 1147-1151Parrow, K.A., Shin, D.H., Tsai, C.S., Hong, Y.J., Juzych, M.S., Shi, D.X., Intraocular messure-dependent dynamic changes of optic disc cupping in adult glaucoma patients (1992) Ophthalmology, 99 (1), pp. 36-40Bowd, C., Weinreb, R.N., Lee, B., Emdadi, A., Zargwill, L.M., Optic disk topography after medical treatment to reduce intraocular pressure (2000) Am J Ophthalmol, 130 (3), pp. 280-286Yamada, N., Tomita, G., Yamamoto, T., Kitazawa, Y., Changes in the nerve fiber layer thickness following a reduction of intraocular pressure after trabeculectomy (2000) J Glaucoma, 9 (5), pp. 371-37

David S Greenfield - One of the best experts on this subject based on the ideXlab platform.

  • DS: Scanning Laser Polarimetry with enhanced corneal compensation and optical coherence tomography in normal and glaucomatous eyes. Invest Ophthalmol Vis Sci 2007
    2020
    Co-Authors: Mitra Sehi, Stephen Ume, David S Greenfield
    Abstract:

    Advanced Imaging in Glaucoma Study Group 2 PURPOSE. To examine the association between Scanning Laser Polarimetry (SLP), using enhanced (ECC) and variable corneal compensation (VCC) with optical coherence tomography (OCT), and to compare their discriminating ability in the diagnosis of glaucoma. METHODS. Normal and glaucomatous eyes enrolled from four clinical sites underwent complete examination, automated perimetry, SLP-ECC, SLP-VCC, and OCT. Eyes were characterized in two groups based on the typical scan score (TSS): Normal birefringence pattern (NBP) was defined as a TSS of 80 to 100 and abnormal birefringence pattern (ABP) as TSS Յ 79. For each of the six SLP parameters and five OCT parameters the areas under the receiver operating characteristic curve (AUROCs) were calculated to compare the discriminating ability of each imaging modality, to differentiate between normal and glaucomatous eyes. RESULTS. Ninety-five normal volunteers and 63 patients with glaucoma were enrolled. Average visual field mean deviation was Ϫ4.2 Ϯ 4.3 dB in the glaucoma group. In eyes with NBP, SLP-ECC had significantly (all P Յ 0.001) greater correlation with OCT average, superior, and inferior retinal nerve fiber layer (RNFL; r ϭ 0.79, 0.67, 0.74) compared with SLP-VCC (r ϭ 0.71, 0.43, 0.37). In eyes with ABP, SLP-ECC had a significantly greater (all P Յ 0.001) correlation with OCT average, superior, and inferior RNFL (r ϭ 0.75, 0.73, 0.83) compared with SLP-VCC (r ϭ 0.51, 0.22, 0.18). The AUROC for OCT inferior average thickness (0.91) was similar (P ϭ 0.26) to the TSNIT (temporal, superior, nasal, inferior, temporal) average obtained using SLP-ECC (0.87) and significantly (P ϭ 0.02) greater than SLP-VCC (0.81). CONCLUSIONS. Compared with SLP-VCC, SLP-ECC has significantly stronger correlations with OCT and may improve the discriminating ability for early glaucoma diagnosis. (Invest Ophthalmol Vis Sci

  • quantitative assessment of atypical birefringence images using Scanning Laser Polarimetry with variable corneal compensation
    American Journal of Ophthalmology, 2005
    Co-Authors: Harmohina Bagga, David S Greenfield, William J Feuer
    Abstract:

    Purpose To define the clinical characteristics of atypical birefringence images and to describe a quantitative method for their identification. Design Prospective, comparative, clinical observational study. Methods Normal and glaucomatous eyes underwent complete examination, standard automated perimetry, Scanning Laser Polarimetry with variable corneal compensation (GDx-VCC), and optical coherence tomography (OCT) of the macula, peripapillary retinal nerve fiber layer (RNFL), and optic disk. Eyes were classified into two groups: normal birefringence pattern (NBP) and atypical birefringence pattern (ABP). Clinical, functional, and structural characteristics were assessed separately. A multiple logistic regression model was used to predict eyes with ABP on the basis of a quantitative scan score generated by a support vector machine (SVM) with GDx-VCC. Results Sixty-five eyes of 65 patients were enrolled. ABP images were observed in 5 of 20 (25%) normal eyes and 23 of 45 (51%) glaucomatous eyes. Compared with eyes with NBP, glaucomatous eyes with ABP demonstrated significantly lower SVM scores ( P R 2 = .75 vs .27). ABP images were significantly correlated with older age ( R 2 = .16, P = .001). The SVM score was the only significant ( P Conclusions ABP images exist in a subset of normal and glaucomatous eyes, are associated with older patient age, and produce an artifactual increase in RNFL thickness using GDx-VCC. The SVM score is highly predictive of ABP images.

  • relationship between visual field sensitivity and retinal nerve fiber layer thickness as measured by Scanning Laser Polarimetry
    Investigative Ophthalmology & Visual Science, 2004
    Co-Authors: P G Schlottmann, David S Greenfield, Stefano De Cilla, Joseph Caprioli, David F Garwayheath
    Abstract:

    PURPOSE: To evaluate the strength and pattern of the relationship between visual field (VF) sensitivity and retinal nerve fiber layer (RNFL) thickness measurements by Scanning Laser Polarimetry (SLP). METHODS: Fifty-four eyes of 54 normal subjects (age, 42 +/- 15 years; VF mean deviation [MD], -0.69 +/- 1.01 dB) and 51 eyes of 51 glaucoma patients (age, 66 +/- 14 years; VF MD, -6.92 +/- 5.43 dB) were imaged with an SLP using fixed corneal compensation (FCC) and variable corneal compensation (VCC). VF sensitivity was recorded in the dB and the 1/L scales. Linear and logarithmic relationships were sought globally and in six VF sectors. Relationships of VF and RNFL thickness with age were sought in normal subjects. RESULTS: Both VF sensitivity and RNFL thickness declined with age (as determined by the regression slope): -0.13% (P = 0.0005) and -0.64% (P = 0.0001) per year for dB and 1/L VF sensitivity, respectively, and -0.25% (P = 0.003) per year for VCC RNFL thickness. FCC RNFL thickness was not statistically significantly related to age. The relationship of VF sensitivity to VCC global (R(2) = 0.49) and sectoral (R(2) = 0.00-0.47) RNFL thickness was greater than for FCC global (R(2) = 0.12) and sectoral (R(2) = 0.00-0.21) RNFL thickness. Relationships were curvilinear with the dB scale, with logarithmic regression of dB VF sensitivity against RNFL thickness being significantly better than linear regression. Logarithmic regression of 1/L VF sensitivity against RNFL thickness was no better than linear regression for all sectors. There was no relationship between VF sensitivity and RNFL thickness in the temporal peripapillary RNFL sector. CONCLUSIONS: The strength of the structure/function relationships compare well with previous reports in the literature. The relationships were curvilinear with the dB scale and linear with the 1/L scale, and were much stronger with VCC than with FCC RNFL thickness measurements.

  • Scanning Laser Polarimetry with variable corneal compensation identification and correction for corneal birefringence in eyes with macular disease
    Investigative Ophthalmology & Visual Science, 2003
    Co-Authors: Harmohina Bagga, David S Greenfield, Robert W Knighton
    Abstract:

    PURPOSE. In Scanning Laser Polarimetry with variable corneal compensation (SLP-VCC), the macula is used as an intraocular polarimeter to calculate and neutralize corneal birefringence based on an intact Henle's layer. The purpose of this investigation was to validate this strategy in eyes with macular structural disease. METHODS. A nerve fiber analyzer was modified to enable the measurement of corneal polarization axis and magnitude so that compensation for corneal birefringence was eye specific. Normal subjects and patients with a variety of pathologic macular conditions underwent complete ocular examination, SLP-VCC, and direct measurement of the corneal polarization axis (CPA), with a slit-lamp-mounted corneal polarimeter. Macular birefringence patterns were classified as well defined, weak, or indeterminate bow ties. A new screen method is described that determines the anterior segment birefringence without relying on the presence of macular bow-tie patterns. RESULTS. Forty-seven eyes (20 normal, 27 with maculopathy) of 47 patients (mean age, 59.0 ± 19.0 years; range, 24-88) were enrolled. The correlation between CPA measured with corneal Polarimetry (CPA by P IV [fourth Purkinje image]) and SLP-VCC was less in eyes with macular disease (R 2 = 0.22, P = 0.024) compared with normal eyes (R 2 = 0.72, P 0.05), eyes with macular disease showed a significant association between CPA and average thickness (R 2 = 0.27, P = 0.005), ellipse average (R 2 = 0.24, P = 0.0085), superior average (R 2 = 0.24, P = 0.009), inferior average (R 2 = 0.28, P = 0.004), and superior integral (R 2 = 0.37, P = 0.0008), suggesting incomplete corneal compensation. Greater correlation between CPA by P IV and CPA derived by SLP-VCC was found by using the screen method (R 2 = 0.83, P < 0.0001) compared with the bow-tie method (R 2 = 0.22, P = 0.024) in eyes with maculopathy. CONCLUSIONS. Macular strategies for neutralization of corneal birefringence using SLP-VCC can fail if Henle's layer is disrupted by macular disease. The screen method provides a more robust measure of the anterior segment birefringence in some eyes with macular disease.

  • measurement of the magnitude and axis of corneal polarization with Scanning Laser Polarimetry
    Archives of Ophthalmology, 2002
    Co-Authors: Robert N Weinreb, David S Greenfield, Christopher Bowd, Linda M Zangwill
    Abstract:

    Background: Scanning Laser Polarimetry uses a polarization compensator to isolate corneal birefringence from the birefringence of the retinal nerve fiber layer. This compensator assumes a fixed corneal polarization magnitude (CPM) of 60 nm and a fixed corneal polarization axis (CPA) of 15° in all subjects. Objectives: To measure the CPM and CPA with a Scanning Laser polarimeter and to determine if the assumed compensation values are representative of those observed in healthy and glaucomatous eyes. Methods: The CPM and CPA were measured in 51 healthy eyes and 55 glaucomatous eyes using a modified Scanning Laser polarimeter (GDx Nerve Fiber Analyzer; Laser Diagnostic Technologies Inc, San Diego, Calif) with an experimental variable CPM and CPA compensator. The CPM and CPA distributions in healthy and glaucomatous eyes were compared, and the CPM and CPA relationships with age, corneal thickness, and corneal curvature were also investigated. Nasally upward CPA values (in degrees) were recorded as negative; nasally downward CPA values were recorded as positive. Results: The CPM and CPA measurements were normally distributed with many eyes having values different from those assumed by the GDx corneal compensator. For healthy and glaucomatous eyes combined, CPM measurements ranged from 7 nm to 91 nm (mean±SD, 40.0±15.7 nm). The CPA measurements ranged from �13° to 73° (mean±SD, 24.5°±17.4°). A significant effect of age on CPA was observed when all eyes were combined (R 2 =0.10; P<.001). There were no differences in CPM or CPA between healthy and glaucomatous eyes after adjusting for age. No effects of corneal thickness on CPM (R 2 =0.04; P=.05) or CPA (R 2 =0.01; P=.24) or of corneal curvature on CPM (R 2 = 0.002; P = .67) or CPA (R 2 =0.009; P=.34) were observed. Conclusions: The range of CPM and CPA values observed in glaucomatous and healthy eyes suggests that the narrow-band corneal compensator used by the GDx Scanning Laser polarimeter is inappropriately compensating for anterior segment birefringence in many eyes.

Hiroshi Ishikawa - One of the best experts on this subject based on the ideXlab platform.

  • imaging of the optic nerve and retinal nerve fiber layer an essential part of glaucoma diagnosis and monitoring
    Survey of Ophthalmology, 2014
    Co-Authors: Jacek Kotowski, Hiroshi Ishikawa, Gadi Wollstein, Joel S Schuman
    Abstract:

    Because glaucomatous damage is irreversible early detection of structural changes in the optic nerve head and retinal nerve fiber layer is imperative for timely diagnosis of glaucoma and monitoring of its progression. Significant improvements in ocular imaging have been made in recent years. Imaging techniques such as optical coherence tomography, Scanning Laser Polarimetry and confocal Scanning Laser ophthalmoscopy rely on different properties of light to provide objective structural assessment of the optic nerve head, retinal nerve fiber layer and macula. In this review, we discuss the capabilities of these imaging modalities pertinent for diagnosis of glaucoma and detection of progressive glaucomatous damage and provide a review of the current knowledge on the clinical performance of these technologies.

  • assessment of optic disc anatomy and nerve fiber layer thickness in ocular hypertensive subjects with normal short wavelength automated perimetry
    Ophthalmology, 2002
    Co-Authors: Andrea Mistlberger, Sek Tien Hoh, David S Greenfield, Jeffrey M Liebmann, Hiroshi Ishikawa, Michael Marmor, Robert Ritch
    Abstract:

    Abstract Purpose To compare optic disc topography and nerve fiber layer thickness in ocular hypertensive eyes and normal subjects. Design Prospective, case-controlled study. Participants and controls One eye in each of 20 normal and 27 ocular hypertensive patients was enrolled. Methods Consecutive normal and ocular hypertensive patients were enrolled. Each patient underwent complete ophthalmic examination, achromatic automated perimetry, short-wavelength automated perimetry, confocal Scanning Laser ophthalmoscopy, confocal Scanning Laser Polarimetry, and optical coherence tomography. The intraocular pressure was 21 mmHg or less for normal subjects and at least 25 mmHg on two separate occasions in ocular hypertensive eyes. Structural parameters were compared between the two groups. Eyes with evidence of glaucomatous optic neuropathy, achromatic visual field loss, or evidence of focal visual field injury during short-wavelength automated perimetry were excluded. Main outcome measures Optic nerve head topography and nerve fiber layer thickness. Results The three imaging technologies could not detect differences in optic disc or nerve fiber layer anatomy between the two groups. Ocular hypertensive eyes had a greater corrected pattern standard deviation than normal eyes during short-wavelength automated perimetry ( P = 0.04). Conclusions Ocular hypertensive eyes with normal achromatic automated perimetry and short-wavelength automated perimetry could not be distinguished from normal subjects with confocal Scanning Laser ophthalmoscopy, confocal Scanning Laser Polarimetry, and optical coherence tomography.

  • optical coherence tomography and Scanning Laser Polarimetry in normal ocular hypertensive and glaucomatous eyes
    American Journal of Ophthalmology, 2000
    Co-Authors: Sek Tien Hoh, David S Greenfield, Andrea Mistlberger, Jeffrey M Liebmann, Hiroshi Ishikawa
    Abstract:

    PURPOSE: To evaluate the relationship between visual function and retinal nerve fiber layer measurements obtained with Scanning Laser Polarimetry and optical coherence tomography in a masked, prospective trial. METHODS: Consecutive normal, ocular hypertensive, and glaucomatous subjects who met inclusion and exclusion criteria were evaluated. Complete ophthalmologic examination, disk photography, Scanning Laser Polarimetry, optical coherence tomography, and automated achromatic perimetry were performed. RESULTS: Seventy-eight eyes of 78 patients (17 normal, 23 ocular hypertensive, and 38 glaucomatous) were enrolled (mean age, 56.8 ± 11.5 years; range, 26 to 75 years). Eyes with glaucoma had significantly greater neural network scores on Scanning Laser Polarimetry and lower maximum modulation, ellipse modulation, and mean retinal nerve fiber layer thickness measured with optical coherence tomography compared with normal and ocular hypertensive eyes, respectively (all P < .005). Significant associations were observed between neural network number (r = −.51, r = .03), maximum modulation (r = .39, r = −.32), ellipse modulation (r = .36, r = −.28), and optical coherence tomography–generated retinal nerve fiber layer thickness (r = .68, r = −.59) and visual field mean deviation and corrected pattern standard deviation, respectively. All Scanning Laser Polarimetry parameters were significantly associated with optical coherence tomography–generated retinal nerve fiber layer thickness. CONCLUSION: Optical coherence tomography and Scanning Laser Polarimetry were capable of differentiating glaucomatous from nonglaucomatous populations in this cohort; however considerable measurement overlap was observed among normal, ocular hypertensive, and glaucomatous eyes. Retinal nerve fiber layer structural measurements demonstrated good correlation with visual function, and retinal nerve fiber layer thickness by optical coherence tomography correlated with retardation measurements by Scanning Laser Polarimetry.

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