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Richard A. Stone - One of the best experts on this subject based on the ideXlab platform.

  • In vivo human Choroidal Thickness measurements: Evidence for diurnal fluctuations
    Investigative Ophthalmology and Visual Science, 2009
    Co-Authors: Jamin S. Brown, Gregor F. Schmid, Graham E. Quinn, Ellie L. Francis, Gui-shuang Ying, D.i. Flitcroft, Richard A. Stone
    Abstract:

    PURPOSE: The authors applied partial coherence interferometry (PCI) to estimate the Thickness of the human choroid in vivo and to learn whether it fluctuates during the day. METHODS: By applying signal processing techniques to existing PCI tracings of human ocular axial length measurements, a signal modeling algorithm was developed and validated to determine the position and variability of a postretinal peak that, by analogy to animal studies, likely corresponds to the Choroidal/scleral interface. The algorithm then was applied to diurnal axial eye length datasets. RESULTS: The postretinal peak was identified in 28% of subjects in the development and validation datasets, with mean subfoveal Choroidal Thicknesses of 307 and 293 microm, respectively. Twenty-eight of 40 diurnal PCI datasets had at least two time points with identifiable postretinal peaks, yielding a mean Choroidal Thickness of 426 microm and a mean high-low difference in Choroidal Thickness of 59.5 +/- 24.2 microm (range, 25.9-103 microm). The diurnal Choroidal Thickness fluctuation was larger than twice the SE of measurement (24.5 microm) in 16 of these 28 datasets. Axial length and Choroidal Thickness tended to fluctuate in antiphase. CONCLUSIONS: Signal processing techniques provide Choroidal Thickness estimates in many, but not all, PCI datasets of axial eye measurements. Based on eyes with identifiable postretinal peaks at more than one time in a day, Choroidal Thickness varied over the day. Because of the established role of the choroid in retinal function and its possible role in regulating eye growth, further development and refinement of clinical methods to measure its Thickness are warranted.

  • in vivo human Choroidal Thickness measurements evidence for diurnal fluctuations
    Investigative Ophthalmology & Visual Science, 2009
    Co-Authors: Jamin S. Brown, Gregor F. Schmid, Graham E. Quinn, Ellie L. Francis, Gui-shuang Ying, Richard A. Stone, Ian D Flitcroft
    Abstract:

    PURPOSE. The authors applied partial coherence interferometry (PCI) to estimate the Thickness of the human choroid in vivo and to learn whether it fluctuates during the day. METHODS. By applying signal processing techniques to existing PCI tracings of human ocular axial length measurements, a signal modeling algorithm was developed and validated to determine the position and variability of a postretinal peak that, by analogy to animal studies, likely corresponds to the Choroidal/scleral interface. The algorithm then was applied to diurnal axial eye length datasets. RESULTS. The postretinal peak was identified in 28% of subjects in the development and validation datasets, with mean subfoveal Choroidal Thicknesses of 307 and 293 m, respectively. Twenty-eight of 40 diurnal PCI datasets had at least two time points with identifiable postretinal peaks, yielding a mean Choroidal Thickness of 426 m and a mean high-low difference in Choroidal Thickness of 59.5 24.2 m (range, 25.9‐103 m). The diurnal Choroidal Thickness fluctuation was larger than twice the SE of measurement (24.5 m) in 16 of these 28 datasets. Axial length and Choroidal Thickness tended to fluctuate in antiphase. CONCLUSIONS. Signal processing techniques provide Choroidal Thickness estimates in many, but not all, PCI datasets of axial eye measurements. Based on eyes with identifiable postretinal peaks at more than one time in a day, Choroidal Thickness varied over the day. Because of the established role of the choroid in retinal function and its possible role in regulating eye growth, further development and refinement of clinical methods to measure its Thickness are warranted. (Invest Ophthalmol Vis Sci. 2009;50:5‐12) DOI:10.1167/iovs.08-1779

Jamin S. Brown - One of the best experts on this subject based on the ideXlab platform.

  • In vivo human Choroidal Thickness measurements: Evidence for diurnal fluctuations
    Investigative Ophthalmology and Visual Science, 2009
    Co-Authors: Jamin S. Brown, Gregor F. Schmid, Graham E. Quinn, Ellie L. Francis, Gui-shuang Ying, D.i. Flitcroft, Richard A. Stone
    Abstract:

    PURPOSE: The authors applied partial coherence interferometry (PCI) to estimate the Thickness of the human choroid in vivo and to learn whether it fluctuates during the day. METHODS: By applying signal processing techniques to existing PCI tracings of human ocular axial length measurements, a signal modeling algorithm was developed and validated to determine the position and variability of a postretinal peak that, by analogy to animal studies, likely corresponds to the Choroidal/scleral interface. The algorithm then was applied to diurnal axial eye length datasets. RESULTS: The postretinal peak was identified in 28% of subjects in the development and validation datasets, with mean subfoveal Choroidal Thicknesses of 307 and 293 microm, respectively. Twenty-eight of 40 diurnal PCI datasets had at least two time points with identifiable postretinal peaks, yielding a mean Choroidal Thickness of 426 microm and a mean high-low difference in Choroidal Thickness of 59.5 +/- 24.2 microm (range, 25.9-103 microm). The diurnal Choroidal Thickness fluctuation was larger than twice the SE of measurement (24.5 microm) in 16 of these 28 datasets. Axial length and Choroidal Thickness tended to fluctuate in antiphase. CONCLUSIONS: Signal processing techniques provide Choroidal Thickness estimates in many, but not all, PCI datasets of axial eye measurements. Based on eyes with identifiable postretinal peaks at more than one time in a day, Choroidal Thickness varied over the day. Because of the established role of the choroid in retinal function and its possible role in regulating eye growth, further development and refinement of clinical methods to measure its Thickness are warranted.

  • in vivo human Choroidal Thickness measurements evidence for diurnal fluctuations
    Investigative Ophthalmology & Visual Science, 2009
    Co-Authors: Jamin S. Brown, Gregor F. Schmid, Graham E. Quinn, Ellie L. Francis, Gui-shuang Ying, Richard A. Stone, Ian D Flitcroft
    Abstract:

    PURPOSE. The authors applied partial coherence interferometry (PCI) to estimate the Thickness of the human choroid in vivo and to learn whether it fluctuates during the day. METHODS. By applying signal processing techniques to existing PCI tracings of human ocular axial length measurements, a signal modeling algorithm was developed and validated to determine the position and variability of a postretinal peak that, by analogy to animal studies, likely corresponds to the Choroidal/scleral interface. The algorithm then was applied to diurnal axial eye length datasets. RESULTS. The postretinal peak was identified in 28% of subjects in the development and validation datasets, with mean subfoveal Choroidal Thicknesses of 307 and 293 m, respectively. Twenty-eight of 40 diurnal PCI datasets had at least two time points with identifiable postretinal peaks, yielding a mean Choroidal Thickness of 426 m and a mean high-low difference in Choroidal Thickness of 59.5 24.2 m (range, 25.9‐103 m). The diurnal Choroidal Thickness fluctuation was larger than twice the SE of measurement (24.5 m) in 16 of these 28 datasets. Axial length and Choroidal Thickness tended to fluctuate in antiphase. CONCLUSIONS. Signal processing techniques provide Choroidal Thickness estimates in many, but not all, PCI datasets of axial eye measurements. Based on eyes with identifiable postretinal peaks at more than one time in a day, Choroidal Thickness varied over the day. Because of the established role of the choroid in retinal function and its possible role in regulating eye growth, further development and refinement of clinical methods to measure its Thickness are warranted. (Invest Ophthalmol Vis Sci. 2009;50:5‐12) DOI:10.1167/iovs.08-1779

Jay S Duker - One of the best experts on this subject based on the ideXlab platform.

  • analysis of normal peripapillary Choroidal Thickness via spectral domain optical coherence tomography
    Ophthalmology, 2011
    Co-Authors: James G Fujimoto, Joseph Ho, Lauren Branchini, Caio V Regatieri, Chandrasekharan Krishnan, Jay S Duker
    Abstract:

    Purpose To analyze the normal peripapillary Choroidal Thickness utilizing a commercial spectral domain optical coherence tomography (OCT) device and determine the intergrader reproducibility of this method. Design Retrospective, noncomparative, noninterventional case series. Participants Thirty-six eyes of 36 normal patients seen at the New England Eye Center between April and September 2010. Methods All patients underwent high-definition scanning with the Cirrus HD-OCT. Two raster scans were obtained per eye, a horizontal and a vertical scan, both of which were centered at the optic nerve. Two independent graders individually measured the Choroidal Thickness. Choroidal Thickness was measured from the posterior edge of the retinal pigment epithelium to the choroid–scleral junction at 500-μm intervals away from the optic nerve in the superior, inferior, nasal, and temporal quadrants. Statistical analysis was conducted to compare mean Choroidal Thicknesses. Intergrader reproducibility was assessed by intraclass correlation coefficient and Pearson's correlation coefficient. Average Choroidal Thickness in each quadrant was compared with retinal nerve fiber layer (RNFL) Thickness in their respective quadrants. Main Outcome Measures Peripapillary Choroidal Thickness, intraclass coefficient, and Pearson's correlation coefficient. Results The peripapillary choroid in the inferior quadrant was significantly thinner compared with all other quadrants ( P P P Conclusions Manual segmentation of the peripapillary Choroidal Thickness is reproducible between graders, suggesting that this method is accurate. The inferior peripapillary choroid was significantly thinner than all other quadrants ( P Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.

  • Choroidal Thickness in normal eyes measured using cirrus hd optical coherence tomography
    American Journal of Ophthalmology, 2010
    Co-Authors: Varsha Manjunath, Mohammad Taha, James G Fujimoto, Jay S Duker
    Abstract:

    Purpose To examine Choroidal Thickness and area in healthy eyes using spectral-domain optical coherence tomography (SD-OCT). Design Retrospective, observational case series. Methods Thirty-four eyes (34 subjects), with no retinal or Choroidal disease, underwent high-definition raster scanning using SD-OCT with frame enhancement software. Choroidal Thickness was measured from the posterior edge of the retinal pigment epithelium to the choroid/sclera junction at 500-μm intervals up to 2500 μm temporal and nasal to the fovea. The central 1-mm area of the choroid was also measured, along with foveal Thickness of the retina. All measurements were performed by 2 independent observers. Statistical analysis was used to correlate inter-observer findings, Choroidal Thickness and area measurements with age, and Choroidal Thickness with retinal foveal Thickness. Results The 34 subjects had a mean age of 51.1 years. Reliable measurements of Choroidal Thickness were obtainable in 74% of eyes examined. Choroidal Thickness and area measurements had strong inter-observer correlation (r = 0.92, P P P P P = .18). Mean Choroidal Thickness showed a pattern of thinnest choroid nasally, thickening in the subfoveal region, and then thinning again temporally. Mean subfoveal Choroidal Thickness was found to be 272 μm (SD, ± 81 μm). Conclusions Choroidal Thickness can be measured using SD-OCT high-definition raster scans in the majority of eyes. Choroidal Thickness across the macula demonstrates a thin choroid nasally, thickest subfoveally, and again thinner temporally, and a trend toward decreasing Choroidal Thickness with age.

Jost B. Jonas - One of the best experts on this subject based on the ideXlab platform.

  • Choroidal Thickness in Open-angle Glaucoma.
    Journal of Glaucoma, 2020
    Co-Authors: Jost B. Jonas, Tessa M Forster, Philippe Steinmetz, Frank C Schlichtenbrede, B Harder
    Abstract:

    Abstract To examine Choroidal Thickness in open-angle glaucoma. The hospital-based case series study included a study group with patients with open-angle glaucoma and a control group. Choroidal Thickness was measured by enhanced depth imaging by spectral domain optical coherence tomography. The study group included 39 patients (71 eyes) and the control group consisted of 189 patients (228 eyes) with no significant difference between both groups in age (P=0.16) and refractive error (P=0.07). Choroidal Thickness in the foveal region (P=0.18), at a distance of 1000 μm from the fovea (P=0.39), 2000 μm from the fovea (P=0.46), and 2500 μm from the fovea (P=0.53) did not vary significantly between both groups. In multivariable analysis with adjustment for age and refractive error, Choroidal Thickness at the fovea [P=0.12; regression coefficient B: minus-8.60; 95% confidence interval (CI): -19.3, 2.1], at a horizontal distance of 1000 μm from the fovea (P=0.30; regression coefficient B: -4.98; 95% CI: -14.3, 4.4), 2000 μm from the fovea (P=0.20; regression coefficient B: -20.9; 95% CI: -53.2, 11.3), and 2500 μm from the fovea (P=0.45; regression coefficient B: -2.70; 95% CI: -9.67, 4.27) was not significantly associated with the diagnosis of glaucoma. In binary regression analysis with adjustment for age and refractive error, presence of glaucoma was significantly associated neither with subfoveal Choroidal Thickness [P=0.12; odds ratio (OR): 0.997; 95% CI: 0.993, 1.001] nor with Choroidal Thickness at a horizontal distance of 1000 μm from the fovea (P=0.47; OR: 0.998; 95% CI: 0.993, 1.002), 2000 μm from the fovea (P=0.23; OR: 0.997; 95% CI: 0.993, 1.002), or 2500 μm from the fovea (P=0.46; OR: 0.998; 95% CI: 0.992, 1.004). After adjusting for age and refractive error, open-angle glaucoma was not significantly associated with a marked thinning or a thickening of the choroid in the foveal and parafoveal region.

  • Choroidal Thickness in nonarteritic anterior ischemic optic neuropathy
    American Journal of Ophthalmology, 2014
    Co-Authors: Alexander K Schuster, Tessa M Forster, Philippe Steinmetz, Frank C Schlichtenbrede, B Harder, Jost B. Jonas
    Abstract:

    Purpose To examine Choroidal Thickness in nonarteritic anterior ischemic optic neuropathy (AION). Design Retrospective case control study. Methods In the eye clinic of the University Medical Center in Mannheim, Germany, we studied a group that consisted of patients with nonarteritic AION and a control group that consisted of individuals with normal fundus. Choroidal Thickness was measured by the enhanced-depth imaging of spectral-domain optical coherence tomography. The main outcome measure was Choroidal Thickness. Results The study group consisted of 20 patients: 11 patients with acute nonarteritic AION and an unaffected contralateral eye and 9 patients with acute unilateral nonarteritic AION and previously nonarteritic AION in the contralateral eye. The control group consisted of 58 patients (58 eyes). In multivariate analysis, thinner subfoveal Choroidal Thickness was associated with the diagnosis of nonarteritic AION ( P  = 0.001; regression coefficient B, −55.1), after adjusting for age ( P P  = 0.20). Similarly, unaffected eyes contralateral to eyes with acute nonarteritic AION as compared to control eyes showed thinner subfoveal Choroidal Thickness ( P  = 0.037) after adjusting for age ( P  = 0.001) and refractive error ( P  = 0.06). In a reverse manner, nonarteritic AION was associated with thinner subfoveal Choroidal Thickness ( P  = 0.007) after adjusting for age, optic disc diameter, gender, and refractive error. Conclusions Eyes affected by nonarteritic AION and unaffected contralateral eyes showed significantly thinner macular choroids than eyes of a control group after adjusting ocular and systemic parameters. A thin choroid may be added to the diagnostic features of nonarteritic AION. Future studies may examine the pathophysiologic meaning of the finding.

  • Choroidal Thickness in age related macular degeneration
    Retina-the Journal of Retinal and Vitreous Diseases, 2014
    Co-Authors: Jost B. Jonas, Tessa M Forster, Philippe Steinmetz, Frank C Schlichtenbrede, B Harder
    Abstract:

    Purpose:To examine Choroidal Thickness in age-related macular degeneration (AMD).Methods:The hospital-based case series study included patients with nonexudative or exudative AMD as study group, and the control group consisted of subjects with a normal fundus. Choroidal Thickness was measured by enh

  • Glaucoma and Choroidal Thickness.
    Journal of ophthalmic and vision research, 2014
    Co-Authors: Jost B. Jonas
    Abstract:

    Since the landmark study by Spaide and colleagues on the development of enhanced depth imaging by optical coherence tomography, an increasing number of studies have addressed Choroidal Thickness in normal eyes, factors associated with Choroidal Thickness in normal eyes, and associations of Choroidal Thickness with various retinal and retinoChoroidal disorders.1-4 These studies have revealed that mean subfoveal Choroidal Thickness (SFCT) in normal eyes is approximately 250μm in a population with mean age of 65 years,5 that it shows huge variability ranging from values as thin as 8μm to as large as 854μm, that it decreases with age by 4µm per year of older age and by 15 µm per diopter of increasing myopia, and that it is associated with male gender, a deeper anterior chamber and a thicker lens.5 Clinical studies also showed that patients with central serous chorioretinopathy have a thickened SFCT in the affected eye as well as in the contralateral unaffected eye, and that patients with polypoidal vascular choroidopathy have increased SFCT in association with dilatation of large Choroidal vessels.2,3 A recent study suggested that Choroidal Thickness is additionally influenced by brain pressure.6 With respect to Choroidal Thickness in angle-closure glaucoma, Arora and colleagues recently reported that Choroidal Thickness was significantly greater in the angle closure glaucoma group than in the open angle glaucoma group and normal subjects, with no significant difference between eyes with open angle glaucoma and normal subjects.7 Also after adjusting for age, axial length, intraocular pressure and central corneal Thickness, Choroidal Thickness was significantly greater in the angle closure glaucoma group than either normal eyes or those with open angle glaucoma. Interestingly, the severity of glaucomatous optic nerve damage as measured by cup/disc ratio or visual field mean deviation was not significantly associated with Choroidal Thickness. In another investigation, Arora and coworkers reported a significant increase in Choroidal Thickness and a decrease in anterior chamber depth when water drinking test was performed in eyes with anterior chamber angle closure as compared to eyes with open anterior chamber angles.8 In another recent study on fellow eyes of 44 patients with unilateral acute primary angle closure, Zhou and colleagues observed that the unaffected fellow eyes had thicker choroid than a group of control eyes after adjusting for age, axial length and gender.9 In this issue of JOVR, Hosseini and colleagues presented a study on macular and peripapillary Choroidal Thickness in patients with perimetric glaucoma.10 They confirm previous investigations which also did not find any significant difference in SFCT between patients with open angle glaucoma and non-glaucomatous individuals11-13 (Jonas JB, Steinmetz P, Forster T, Schlichtenbrede FC, Harder B. Choroidal Thickness in open-angle glaucoma. J Glaucoma 2014; in Press). Hosseini and colleagues extended the examinations into the peripapillary region in which, except for the temporal region, Choroidal Thickness did not differ between glaucomatous and control eyes. As also discussed by Hosseini et al, these findings may imply that Choroidal blood circulation may not be markedly involved or affected in open angle glaucoma. As in many situations, there are caveats. The most important layer for nourishment of the retinal pigment epithelium and the outer retina is the choriocapillaris, which makes up less than 20 µm (or less than 10%) of the whole choroid. The choriocapillaris is too thin and the contrast between it and neighboring structures is too weak to make it visible on OCT images. The results of the study by Hosseini et al therefore do not allow to conclude whether or not blood perfusion in the choriocapillaris is affected or primarily involved in the process of open angle glaucoma. This issue is also of importance for discussion on the pathogenesis of beta zone parapapillary atrophy. According to recent histomorphological studies and clinical investigations, one may differentiate between an alpha zone, characterized by the presence of Bruch´s membrane (which can be visualized on OCT images) and the presence of an irregularly structured retinal pigment epithelium; a beta zone is characterized by the presence of Bruch´s membrane but absence of retinal pigment epithelium, while a gamma zone is characterized by the absence of Bruch´s membrane (and therefore by the absence of retinal pigment epithelium).14-17 This newly defined beta zone is associated mostly with glaucoma but not with axial myopia, while gamma zone is associated mostly with axial myopia, but not with glaucoma. Since the retinal pigment epithelium depends for nourishment on the choriocapillaris and since glaucoma associated beta zone is characterized by loss of retinal pigment epithelium, it may be seductive to think of a primary insufficiency of the choriocapillaris in glaucomatous eyes, leading to loss of the retinal pigment epithelium. The study by Hosseini did not support this notion, however, due to limitation in the spatial resolution of the OCT technology, the results do neither contradict it. In conclusion, the carefully planned and conducted study by Hosseini and colleagues highlights the possibility of imaging the choroid by OCT technology and shows the potential impact Choroidal imaging may have on discussions on pathomechanisms of major eye diseases and on decision making in daily ophthalmic practice.

  • Choroidal Thickness in idiopathic subfoveal Choroidal neovascularization.
    Ophthalmologica, 2014
    Co-Authors: Xiao-yan Peng, Yong-peng Zhang, Jost B. Jonas
    Abstract:

    Purpose: To evaluate Choroidal Thickness in patients with idiopathic Choroidal neovascularization. Methods: The observationa

Graham E. Quinn - One of the best experts on this subject based on the ideXlab platform.

  • In vivo human Choroidal Thickness measurements: Evidence for diurnal fluctuations
    Investigative Ophthalmology and Visual Science, 2009
    Co-Authors: Jamin S. Brown, Gregor F. Schmid, Graham E. Quinn, Ellie L. Francis, Gui-shuang Ying, D.i. Flitcroft, Richard A. Stone
    Abstract:

    PURPOSE: The authors applied partial coherence interferometry (PCI) to estimate the Thickness of the human choroid in vivo and to learn whether it fluctuates during the day. METHODS: By applying signal processing techniques to existing PCI tracings of human ocular axial length measurements, a signal modeling algorithm was developed and validated to determine the position and variability of a postretinal peak that, by analogy to animal studies, likely corresponds to the Choroidal/scleral interface. The algorithm then was applied to diurnal axial eye length datasets. RESULTS: The postretinal peak was identified in 28% of subjects in the development and validation datasets, with mean subfoveal Choroidal Thicknesses of 307 and 293 microm, respectively. Twenty-eight of 40 diurnal PCI datasets had at least two time points with identifiable postretinal peaks, yielding a mean Choroidal Thickness of 426 microm and a mean high-low difference in Choroidal Thickness of 59.5 +/- 24.2 microm (range, 25.9-103 microm). The diurnal Choroidal Thickness fluctuation was larger than twice the SE of measurement (24.5 microm) in 16 of these 28 datasets. Axial length and Choroidal Thickness tended to fluctuate in antiphase. CONCLUSIONS: Signal processing techniques provide Choroidal Thickness estimates in many, but not all, PCI datasets of axial eye measurements. Based on eyes with identifiable postretinal peaks at more than one time in a day, Choroidal Thickness varied over the day. Because of the established role of the choroid in retinal function and its possible role in regulating eye growth, further development and refinement of clinical methods to measure its Thickness are warranted.

  • in vivo human Choroidal Thickness measurements evidence for diurnal fluctuations
    Investigative Ophthalmology & Visual Science, 2009
    Co-Authors: Jamin S. Brown, Gregor F. Schmid, Graham E. Quinn, Ellie L. Francis, Gui-shuang Ying, Richard A. Stone, Ian D Flitcroft
    Abstract:

    PURPOSE. The authors applied partial coherence interferometry (PCI) to estimate the Thickness of the human choroid in vivo and to learn whether it fluctuates during the day. METHODS. By applying signal processing techniques to existing PCI tracings of human ocular axial length measurements, a signal modeling algorithm was developed and validated to determine the position and variability of a postretinal peak that, by analogy to animal studies, likely corresponds to the Choroidal/scleral interface. The algorithm then was applied to diurnal axial eye length datasets. RESULTS. The postretinal peak was identified in 28% of subjects in the development and validation datasets, with mean subfoveal Choroidal Thicknesses of 307 and 293 m, respectively. Twenty-eight of 40 diurnal PCI datasets had at least two time points with identifiable postretinal peaks, yielding a mean Choroidal Thickness of 426 m and a mean high-low difference in Choroidal Thickness of 59.5 24.2 m (range, 25.9‐103 m). The diurnal Choroidal Thickness fluctuation was larger than twice the SE of measurement (24.5 m) in 16 of these 28 datasets. Axial length and Choroidal Thickness tended to fluctuate in antiphase. CONCLUSIONS. Signal processing techniques provide Choroidal Thickness estimates in many, but not all, PCI datasets of axial eye measurements. Based on eyes with identifiable postretinal peaks at more than one time in a day, Choroidal Thickness varied over the day. Because of the established role of the choroid in retinal function and its possible role in regulating eye growth, further development and refinement of clinical methods to measure its Thickness are warranted. (Invest Ophthalmol Vis Sci. 2009;50:5‐12) DOI:10.1167/iovs.08-1779