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Lin C, Toychiev A, Ablordeppey R, Slavi N, Srinivas M, Benavente-Perez A. Myopia Alters the Structural Organization of the Retinal Vasculature, GFAP-Positive Glia, and Ganglion Cell Layer Thickness. Int J Mol Sci 2022; 23:6202. [PMID: 35682880 PMCID: PMC9181442 DOI: 10.3390/ijms23116202] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/22/2022] [Accepted: 05/30/2022] [Indexed: 11/17/2022] Open
Abstract
To describe the effect of myopic eye growth on the structure and distribution of astrocytes, vasculature, and retinal nerve fiber layer thickness, which are critical for inner retinal tissue homeostasis and survival. Astrocyte and capillary distribution, retinal nerve fiber (RNFL), and ganglion cell layer (GCL) thicknesses were assessed using immunochemistry and spectral domain optical coherence tomography on eleven retinas of juvenile common marmosets (Callithrix Jacchus), six of which were induced with lens-induced myopia (refraction, Rx: -7.01 ± 1.8D). Five untreated age-matched juvenile marmoset retinas were used as controls (Rx: -0.74 ± 0.4D). Untreated marmoset eyes grew normally, their RNFL thickened and their astrocyte numbers were associated with RNFL thickness. Marmosets with induced myopia did not show this trend and, on the contrary, had reduced astrocyte numbers, increased GFAP-immunopositive staining, thinner RNFL, lower peripheral capillary branching, and increased numbers of string vessels. The myopic changes in retinal astrocytes, vasculature, and retinal nerve fiber layer thickness suggest a reorganization of the astrocyte and vascular templates during myopia development and progression. Whether these adaptations are beneficial or harmful to the retina remains to be investigated.
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Affiliation(s)
| | | | | | | | | | - Alexandra Benavente-Perez
- Department of Biological Sciences, SUNY College of Optometry, New York, NY 10036, USA; (C.L.); (A.T.); (R.A.); (N.S.); (M.S.)
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Kim G, Lee EJ, Kim T. Parapapillary choroidal microvasculature dropout in nonglaucomatous healthy eyes. Acta Ophthalmol 2020; 98:e754-e760. [PMID: 32115892 DOI: 10.1111/aos.14385] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 02/05/2020] [Indexed: 12/18/2022]
Abstract
PURPOSE To determine the incidence of parapapillary choroidal microvasculature dropout (MvD) in nonglaucomatous healthy eyes using optical coherence tomography angiography (OCTA) and to characterize the MvD observed in these eyes. METHODS Seventy-six eyes (19 eyes with an MvD and 57 age-matched eyes without an MvD) from a cohort of 297 nonglaucomatous healthy eyes that underwent OCTA were included. The peripapillary choroidal microvasculature was evaluated in en-face images obtained using swept-source OCTA. An MvD was defined as a focal sectoral capillary dropout with no visible microvascular network identified in the en-face images of the choroidal layer. The incidence of MvD and clinical characteristics associated with the presence of an MvD was determined. RESULTS MvD was found in 19 of the 297 nonglaucomatous healthy eyes (6.4%). Compared with age-matched eyes without an MvD, eyes with an MvD had lower systolic blood pressure (p = 0.021), diastolic blood pressure (p = 0.048), mean arterial pressure (p = 0.025) and mean ocular perfusion pressure (p = 0.032). Logistic regression analyses showed that cold extremities (p = 0.046), lower mean arterial pressure (p = 0.021) and lower mean ocular perfusion pressure (p = 0.023) were associated with the presence of an MvD. CONCLUSIONS Parapapillary choroidal MvD can be present in nonglaucomatous healthy eyes. The presence of an MvD is associated with systemic vascular dysregulation.
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Affiliation(s)
- Gyu‐Nam Kim
- Department of Ophthalmology Institute of Health Sciences Gyeongsang National University School of Medicine Gyeongsang National University Hospital Jinju South Korea
| | - Eun Ji Lee
- Department of Ophthalmology Seoul National University College of Medicine Seoul National University Bundang Hospital Seongnam South Korea
| | - Tae‐Woo Kim
- Department of Ophthalmology Seoul National University College of Medicine Seoul National University Bundang Hospital Seongnam South Korea
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Relationship Between OCT Angiography Temporal Peripapillary Vessel-Density and Octopus Perimeter Paracentral Cluster Mean Defect. J Glaucoma 2017; 26:397-402. [DOI: 10.1097/ijg.0000000000000630] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Holló G. Relationship between optical coherence tomography sector peripapillary angioflow-density and Octopus visual field cluster mean defect values. PLoS One 2017; 12:e0171541. [PMID: 28152106 PMCID: PMC5289610 DOI: 10.1371/journal.pone.0171541] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 01/17/2017] [Indexed: 11/18/2022] Open
Abstract
Purpose To compare the relationship of Octopus perimeter cluster mean-defect (cluster MD) values with the spatially corresponding optical coherence tomography (OCT) sector peripapillary angioflow vessel-density (PAFD) and sector retinal nerve fiber layer thickness (RNFLT) values. Methods High quality PAFD and RNFLT images acquired on the same day with the Angiovue/RTVue-XR Avanti OCT (Optovue Inc., Fremont, USA) on 1 eye of 27 stable early-to-moderate glaucoma, 22 medically controlled ocular hypertensive and 13 healthy participants were analyzed. Octopus G2 normal visual field test was made within 3 months from the imaging. Results Total peripapillary PAFD and RNFLT showed similar strong positive correlation with global mean sensitivity (r-values: 0.6710 and 0.6088, P<0.0001), and similar (P = 0.9614) strong negative correlation (r-values: -0.4462 and -0.4412, P≤0.004) with global MD. Both inferotemporal and superotemporal sector PAFD were significantly (≤0.039) lower in glaucoma than in the other groups. No significant difference between the corresponding inferotemporal and superotemporal parameters was seen. The coefficient of determination (R2) calculated for the relationship between inferotemporal sector PAFD and superotemporal cluster MD (0.5141, P<0.0001) was significantly greater than that between inferotemporal sector RNFLT and superotemporal cluster MD (0.2546, P = 0.0001). The R2 values calculated for the relationships between superotemporal sector PAFD and RNFLT, and inferotemporal cluster MD were similar (0.3747 and 0.4037, respectively, P<0.0001). Conclusion In the current population the relationship between inferotemporal sector PAFD and superotemporal cluster MD was strong. It was stronger than that between inferotemporal sector RNFLT and superotemporal cluster MD. Further investigations are necessary to clarify if our results are valid for other populations and can be usefully applied for glaucoma research.
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Affiliation(s)
- Gábor Holló
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
- * E-mail:
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Lee SH, Lee EJ, Kim TW. Topographic Correlation Between Juxtapapillary Choroidal Thickness and Microstructure of Parapapillary Atrophy. Ophthalmology 2016; 123:1965-73. [DOI: 10.1016/j.ophtha.2016.05.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 05/04/2016] [Accepted: 05/06/2016] [Indexed: 10/21/2022] Open
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Ho J, Branchini L, Regatieri C, Krishnan C, Fujimoto JG, Duker JS. Analysis of normal peripapillary choroidal thickness via spectral domain optical coherence tomography. Ophthalmology 2011; 118:2001-7. [PMID: 21703691 DOI: 10.1016/j.ophtha.2011.02.049] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 02/02/2011] [Accepted: 02/25/2011] [Indexed: 11/17/2022] Open
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<0.001). None of the other quadrants were significantly different from each other in terms of thickness. The inferior peripapillary choroid was significantly thinner compared with all other quadrants at all distances measured away from the optic nerve (P<0.001). Generally, the peripapillary choroid increases in thickness the farther it was away from the optic nerve and eventually approaching a plateau. The intraclass correlation coefficient ranged from 0.62 to 0.93 and Pearson's correlation coefficient ranged from 0.74 to 0.95 (P<0.001). Neither RNFL thickness nor average age was significantly correlated with average choroidal thickness. 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<0.001). FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.
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Affiliation(s)
- Joseph Ho
- New England Eye Center, Tufts Medical Center, Boston, MA 02111, USA
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Loukovaara S, Harju M, Immonen I. Macular blood flow measured by blue-field entoptoscopy and Heidelberg retinal flowmetry: comparison of two techniques in type 1 diabetes women during pregnancy. Acta Ophthalmol 2009; 87:506-10. [PMID: 19053960 DOI: 10.1111/j.1755-3768.2008.01303.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE This study compared macular capillary leucocyte velocity values measured with a psychophysical blue-field entoptic simulation (BFS) technique and confocal scanning laser Doppler flowmetry. METHODS A cross-sectional study was performed where macular capillary leucocyte velocity was measured by BFS using an Oculix BFS-2000 V2.1 psychophysical system and by confocal scanning laser Doppler flowmetry using Heidelberg retinal flowmetry (HRF) in 35 type 1 diabetes women during the second trimester. RESULTS The macular leucocyte velocities measured with BFS correlated significantly with the 50th percentile (r = 0.345, p = 0.042, n = 35, Spearman's non-parametric correlation), the 75th percentile (r = 0.432, p = 0.009) and the 90th percentile (r = 0.373, p = 0.027) of HRF flow values during the second trimester. However, there was no correlation between BFS velocity and the 25th percentile of HRF measurements. CONCLUSIONS Blue-field simulation is known to be an experimental technique that provides a quantitative measure of flow in the perifoveal capillary network. By contrast, HRF imaging reflects quantitative, multispectral, objective and non-invasive measurements in a two-dimensional projection of a three-dimensional retinal capillary bed. Our study showed that BFS velocity was correlated with HRF values in a group of women with diabetes during pregnancy. The positive correlation between BFS and HRF values suggests that the psychophysical BFS and scanning laser-based HRF measure similar functions in the retina.
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Affiliation(s)
- Sirpa Loukovaara
- Department of Ophthalmology, Helsinki University Central Hospital, Finland.
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Interobserver Repeatability of Heidelberg Retinal Flowmetry Using Pixel-by-Pixel Analysis. J Glaucoma 2009; 18:280-3. [DOI: 10.1097/ijg.0b013e318181544a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Harju M, Kurvinen L, Saari J, Vesti E. Blood flow in the peripapillary retina in exfoliation glaucoma. Clin Exp Ophthalmol 2008; 36:738-43. [DOI: 10.1111/j.1442-9071.2008.01884.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Harris A, Kagemann L, Ehrlich R, Rospigliosi C, Moore D, Siesky B. Measuring and interpreting ocular blood flow and metabolism in glaucoma. Can J Ophthalmol 2008; 43:328-36. [DOI: 10.3129/i08-051] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Mavroudis L, Harris A, Topouzis F, Wilson MR, Yu F, Anastasopoulos E, Koskosas A, Siesky B, Pappas T, Founti P, Coleman AL. Reproducibility of pixel-by-pixel analysis of Heidelberg retinal flowmetry images: the Thessaloniki Eye Study. Acta Ophthalmol 2008; 86:81-6. [PMID: 17850404 DOI: 10.1111/j.1600-0420.2007.01003.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To identify the investigator effect in the analysis results of Heidelberg retinal flowmetry (HRF) images when pixel-by-pixel analysis is performed. METHODS Thirty-two of 732 HRF images were randomly selected from a population-based study. Pixel-by-pixel analysis was performed by two trained masked graders in the following way: a square window of 40 x 40 pixels or two windows of 30 x 30 pixels or four windows of 20 x 20 pixels free from blood vessels at the peripapillary retina were identified. Using a 1 x 1-pixel window, the grader performed pointwise analysis according to a specific protocol. The analysis process was performed by each observer three times (A, B, C) at 1-week intervals. The percentage of pixels with < 1 arbitrary unit of flow (zero flow), the 10th, 25th, 50th, 75th and 90th percentiles and mean flow values were calculated. The difference between the results of analyses B-A and C-A for all HRF parameters was estimated using the Wilcoxon signed rank test. Mixed-effect regression models were also used after controlling for grader effect and correlation within subjects. RESULTS There was no statistically significant difference between the results of analyses B-A and C-A or for any parameter in the mixed-effect regression models. Intraclass correlation was 0.9665 for the percentage of zero flow pixels. CONCLUSIONS Pixel-by-pixel analysis of HRF images by trained graders remains a highly reproducible method. No grader effect was found. If a precise protocol is followed, the results are independent of the exact placement of the analysis windows and the pointwise analysis of the identified and mapped retinal tissue.
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Affiliation(s)
- Leonidas Mavroudis
- II Department of Ophthalmology, Aristotle University of Thessaloniki, Thessaloniki, Greece
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Sato EA, Ohtake Y, Shinoda K, Mashima Y, Kimura I. Decreased blood flow at neuroretinal rim of optic nerve head corresponds with visual field deficit in eyes with normal tension glaucoma. Graefes Arch Clin Exp Ophthalmol 2005; 244:795-801. [PMID: 16315043 DOI: 10.1007/s00417-005-0177-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2005] [Revised: 09/14/2005] [Accepted: 10/06/2005] [Indexed: 10/25/2022] Open
Abstract
PURPOSE To determine the relationship between the blood flow parameters of the optic disc rim and the glaucomatous visual field changes. DESIGN Observational cross-sectional study. METHODS Tissue blood flow in the neuroretinal rim within the optic disc was determined with the Heidelberg retina flowmeter(HRF) in 54 eyes of 54 patients with normal tension glaucoma (NTG). Patients were selected whose visual field defects were confined to either the superior or inferior hemifield. Blood flow measurements were made in a 10 degrees x 2.5 degrees area of the superior and inferior neuroretinal rim within the optic disc. The mean blood flow (MBF) was calculated by the automatic full-field perfusion image analyzer program, and the ratio of the MBF in the superior to the inferior rim areas (the S/I ratio) was calculated from the same HRF image in order to minimize the variation of measurement condition. RESULTS Inferior rim blood flow is less than superior rim blood flow in patients with superior hemifield defect, and superior rim blood flow is reduced compared to inferior in patients with inferior hemifield defect. The mean S/I ratios of the MBF in the patients with superior hemifield defect (1.46, n=37) was significantly higher than that in the patients with inferior hemifield defect (0.79, n=17; P<0.0001, Mann-Whitney U-test). CONCLUSIONS The blood flow in the neuroretinal rim was found to correspond to the regional visual field defect in eyes with NTG. Reductions in flow were associated with reductions in function.
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Affiliation(s)
- Enrique Adan Sato
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, 160-8582 Tokyo, Japan
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Jonescu-Cuypers CP, Harris A, Wilson R, Kagemann L, Mavroudis LV, Topouzis F, Coleman AL. Reproducibility of the Heidelberg retinal flowmeter in determining low perfusion areas in peripapillary retina. Br J Ophthalmol 2004; 88:1266-9. [PMID: 15377548 PMCID: PMC1772337 DOI: 10.1136/bjo.2003.039099] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To evaluate the interobserver variability and retest reproducibility of confocal scanning laser Doppler flowmeter in measuring capillary perfusion of the peripapillary retina. METHODS Blood flow measurements were performed in one eye of 10 normal subjects by two investigators on two different days (visits). Five separate measurements of the peripapillary blood flow parameters were recorded by each observer at each visit. The Heidelberg retina flowmeter was used to record capillary perfusion in a 2560x640 microm area of the superotemporal peripapillary region and pixel by pixel analysis was done from an area adjacent to the optic disc, with a minimum of 1600 pixels. The percentage of pixels with less than 1 arbitrary unit of flow (no flow) and 10, 25, 50, 75, 90th percentiles of flow values was calculated. Interobserver measurements were compared by paired t test. Intraclass correlations (ICC) were used to determine the interobserver variability and retest reproducibility of the measurements. Intrasession coefficients of variations (CV) were also calculated. RESULTS There were no statistically significant differences between the two observers for all measurements and between visits for the percentage of pixels with no flow. ICC was 66% (range 57.09%-77.1%) for pixels with no flow. For the 10, 25, 50, 75, 90th percentiles of flow the ICC was 63.07% (53.91%-77.81%), 71.3% (64.23%-80.85%), 72.61% (66.02%-78.96%), 65.86% (58.53%-74.77%), and 60.05% (54.34%-70.06%), respectively. CV was 16.59%, 11.47%, 9.32%, 9.03%, 11.58%, and 16.05% for the percentage of no flow pixels and the 10, 25, 50, 75, 90th percentiles of flow, respectively. CONCLUSIONS The Heidelberg retinal flowmeter allows reproducible measurements of all levels of capillary perfusion areas when pixel by pixel analysis is used.
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Jonescu-Cuypers CP, Harris A, Bartz-Schmidt KU, Kagemann L, Boros AS, Heimann UE, Lenz BH, Hilgers RD, Krieglstein GK. Reproducibility of circadian retinal and optic nerve head blood flow measurements by Heidelberg retina flowmetry. Br J Ophthalmol 2004; 88:348-53. [PMID: 14977767 PMCID: PMC1772040 DOI: 10.1136/bjo.2003.024885] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND/AIM The Heidelberg retina flowmeter (HRF) is designed to measure retinal capillary blood flow. Previous studies however showed weak reproducibility of data. The intraindividual reproducibility of circadian HRF measurements was examined in healthy subjects in three locations of the retina. METHODS 36 healthy volunteers (27.3 (SD 4.3) years) were examined by HRF seven times a day (t0-t6). Using a default window of 10 x 10 pixels, three consecutive measurements were performed in three precise focusing planes: superficial, intermediate and deep layer, peripapillary retina, neuroretinal rim and cup, respectively. Images of identical tissue locations identified by capillary landmarks of each layer were selected to quantify the retinal microcirculation of each volunteer. Means and standard deviations of all flow results of a given subject were calculated, at t0-t6 and the coefficients of variation as a measure of reproducibility. RESULTS The coefficients of variation ranged between 8.4% and 41.0% in the superficial layer (mean 19.8% (SD 8.4%)), 10.6%, and 43.0% in the intermediate layer (mean 24.0% (SD 8.4%)), and 9.9% and 84.0% (mean 29.6% (SD 15.8%)) in the deep layer. CONCLUSIONS These data show the best reproducibility of measurements in the superficial layer followed by the intermediate and the deep layer. Clinically, this is an unsatisfactory intraindividual reproducibility of flow values in each studied layer.
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Kimura I, Shinoda K, Tanino T, Ohtake Y, Mashima Y, Oguchi Y. Scanning laser Doppler flowmeter study of retinal blood flow in macular area of healthy volunteers. Br J Ophthalmol 2004; 87:1469-73. [PMID: 14660455 PMCID: PMC1920574 DOI: 10.1136/bjo.87.12.1469] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To compare the interocular and intraocular differences of capillary perfusion, and the intraocular regional differences of retinal blood flow in the macular area of healthy volunteers. METHODS Tissue blood flow in the macula was examined in both eyes of 20 healthy volunteers with the Heidelberg retinal flowmeter. Blood flow measurements were made in a 10 degrees x 2.5 degrees area superior and inferior to the macula. The mean blood flow (MBF) was calculated by an automatic full field perfusion image analyser program. The MBF in the right and left eyes and in the superior and inferior macular areas of the same eye were compared. RESULTS The ratios of the MBF in the right eye to the left eye in the macular areas were 1.00, and 1.03, respectively. The ratio of the MBF in the superior macular area to the inferior area was 1.01 for the right eyes and 1.04 for the left eyes. CONCLUSIONS Because no significant differences were found in the MBF between the two eyes and between the superior and inferior macular areas in the same eye, interocular (for example, affected eye versus fellow eye) and intraocular (superior versus inferior macular areas) comparisons of MBF can be made to determine if changes in retinal perfusion have occurred.
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Affiliation(s)
- I Kimura
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
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Hafez AS, Bizzarro RLG, Lesk MR. Evaluation of optic nerve head and peripapillary retinal blood flow in glaucoma patients, ocular hypertensives, and normal subjects. Am J Ophthalmol 2003; 136:1022-31. [PMID: 14644212 DOI: 10.1016/s0002-9394(03)00632-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
PURPOSE To compare optic nerve head (ONH) and peripapillary retinal blood flow in subjects with open-angle glaucoma (OAG), ocular hypertension (OHT), and normal eyes (NOR) using full-field perfusion analysis of scanning laser Doppler flowmetry (SLDF) images. DESIGN Prospective, nonrandomized clinical trial. METHODS Twenty uncontrolled OAG patients, 20 uncontrolled OHT patients, and 20 normal volunteers were prospectively enrolled. Mean ONH and peripapillary retinal blood flow measurements were performed by SLDF version 3.3 using five Heidelberg Retina Flowmeter (Heidelberg Engineering, Heidelberg, Germany) images. Statistical evaluations were performed on the three study groups using one-way analysis of variance. Flow values of the neuroretinal rim of the ONH, nasal peripapillary retina, and temporal peripapillary retina were then correlated with the clinical parameters of age, cup/disk (C/D) ratio, intraocular pressure (IOP), visual field mean defect, maximum-recorded IOP, and ocular perfusion pressure. Neuroretinal rim blood flow in the OAG group was 158 +/- 79 arbitrary units (au), whereas in the OHT group it was 277 +/- 158 au, and in the NOR group it was 272 +/- 93 au. Differences were statistically significant between the OAG group and each of the other groups (P =.001) but not between OHT and NOR groups (P =.91). Peripapillary retinal flow values showed no statistically significant differences between groups (P =.76 nasal and 0.93 temporal). RESULTS Neuroretinal rim flow values showed a significant inverse correlation with C/D ratio (P =.001). Mean neuroretinal rim blood flow was significantly higher (350 +/- 184 au) in the 10 OHT patients with C/D ratios < 0.4 when compared with the 10 OHT patients with larger C/D ratios (203 +/- 79 au) (P =.039). Conversely, peripapillary retinal blood flow showed no significant correlation with any clinical parameter. CONCLUSION Open-angle glaucoma patients had significantly lower blood flow in the ONH compared with OHT patients and normal volunteers. No significant differences in ONH blood flow were found between ocular hypertensives and normal volunteers. For peripapillary retinal blood flow, no significant difference was seen between any groups. Neuroretinal rim blood flow was significantly inversely correlated to increased C/D ratio. Ocular hypertensives with larger C/D ratios demonstrated significantly lower rim blood flow compared with those with smaller C/D ratios, suggesting that rim perfusion might be reduced in high-risk ocular hypertensives before the manifestation of visual field defects.
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Affiliation(s)
- Ali S Hafez
- Department of Ophthalmology and Guy-Bernier Research Center, Maisonneuve-Rosemont Hospital, University of Montreal, Montréal, Canada
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Hosking SL, Embleton SJ, Cunliffe IA. Application of a local search strategy improves the detection of blood flow deficits in the neuroretinal rim of glaucoma patients using scanning laser Doppler flowmetry. Br J Ophthalmol 2001; 85:1298-302. [PMID: 11673292 PMCID: PMC1723767 DOI: 10.1136/bjo.85.11.1298] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND/AIM Blood flow measures acquired using the scanning laser Doppler flowmeter (SLDF) are known to be highly susceptible to spatial and temporal variations of physiological origin. The purpose of this study was to evaluate a local search strategy intended to overcome these intrinsic variations, thereby improving the detection of blood flow defects resulting from glaucoma. METHODS The sample consisted of one eye of each of 15 glaucoma patients (aged 69.1 (SD 6.6) years) and 15 normal subjects (aged 65.2 (13.7) years). Three 10 degree images of the superior temporal retina and three images of the superior temporal rim were acquired using the Heidelberg retina flowmeter (HRF). Standard analysis was performed using a 10 x 10 pixel frame. For the search strategy the same frame was located within a 15 x 15 pixel window and manually repositioned in order to identify the highest and lowest local values of blood flow. Student's paired t test was used to identify differences between groups for the two methods (p<0.05). RESULTS The standard strategy revealed no significant differences in blood flow measures between the subjects at either the retina or neuroretinal rim. With the search strategy there was also no difference in blood flow measures at the retina. At the neuroretinal rim, the search strategy demonstrated that the highest measured blood flow, volume, and velocity values were significantly lower for the glaucoma patients (p = 0.002, 0.02, and 0.002 respectively) while comparison of the lowest flow values showed that glaucoma patients had lower blood flow and velocity only (p = 0.023 and 0.021 respectively). CONCLUSIONS Glaucoma patients exhibit reduced ocular blood flow at the neuroretinal rim, which seems to affect high velocity flow more profoundly than low velocity flow. When analysing perfusion images a local search strategy is recommend to identify the highest local blood flow values in order to optimise the ability to differentiate between subject groups.
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Affiliation(s)
- S L Hosking
- Neurosciences Research Institute, Aston University, Aston Triangle, Birmingham B4 7ET, UK.
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Németh J, Michelson G, Harazny J. Retinal microcirculation correlates with ocular wall thickness, axial eye length, and refraction in glaucoma patients. J Glaucoma 2001; 10:390-5. [PMID: 11711836 DOI: 10.1097/00061198-200110000-00005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To examine the correlations of refraction, axial eye length, and posterior eye wall thickness with retinal microcirculation. PATIENTS AND METHODS In a prospective study, 25 patients with primary open-angle glaucoma, 12 patients with ocular hypertension, and 12 healthy subjects were examined; only one eye of each participant was considered in the analysis. Posterior eye wall thickness and axial eye length were measured with standardized A-scan ultrasonography. Retinal microcirculation temporal to the optic disc was determined by a scanning laser Doppler flowmeter using automatic full-field perfusion image analyzer software. RESULTS In glaucoma patients, temporal retinal mean flow exhibited significant correlation to the eye wall thickness (r = 0.470, P = 0.042), axial eye length (r = -0.570, P = 0.011), and refraction of the eye (r = 0.520, P = 0.022). In glaucomatous eyes, the temporal retinal mean flow was significantly lower than in healthy subjects or in ocular hypertensive patients (P = 0.01). CONCLUSIONS Myopic eyes have longer axial eye length and thinner ocular wall than emmetropic eyes. In glaucoma patients, the longer the axial eye length and the thinner the ocular wall, the more reduced the retinal microcirculation. The reduced microcirculation found in myopic glaucomatous eyes might contribute to the development of glaucomatous damage in these eyes.
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Affiliation(s)
- J Németh
- First Department of Ophthalmology, Semmelweis University, Budapest, Hungary
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Squirrell DM, Watts A, Evans D, Mody C, Talbot JF. A prospective evaluation of the Heidelberg retina flowmeter in diagnosing ischaemia following branch retinal vein occlusion: a masked, controlled comparison with fluorescein angiography. Eye (Lond) 2001; 15:261-6. [PMID: 11450717 DOI: 10.1038/eye.2001.91] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To evaluate the use of the Heidelberg retina flowmeter (HRF) in diagnosing retinal ischaemia following macular branch retinal vein occlusion. METHODS Ten patients with ischaemic macular branch retinal vein occlusion, as determined by strict fluorescein angiographic criteria, were examined with the HRF. Blood flow, blood volume and blood velocity characteristics from areas of ischaemic and non-ischaemic retina were recorded and the results between the normal and ischaemic areas of retina compared with paired t-test analysis. Ten healthy volunteers were similarly examined and acted as a control group. RESULTS Compared with normal retina the HRF recorded a statistically significant reduction in blood flow within the ischaemic retina in 7 of the 10 study patients. In 2 patients the HRF actually recorded a statistically significant increase in blood flow in the area of ischaemic retina; there was no significant difference in the blood flow recorded in the normal and ischaemic retina in the remaining patient. HRF examination of the control group revealed a significant difference in the blood flow between two areas of apparently normal retina in 3 of the 10 volunteers. CONCLUSION The HRF is not a reliable tool for diagnosing retinal ischaemia following branch retinal vein occlusion. Our results may suggest that the HRF blood flow recordings are not derived from the retinal circulation alone, but represent the cumulative blood flow through the combined circulations of the retina and choriocapillaris.
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Affiliation(s)
- D M Squirrell
- Department of Ophthalmology, Royal Hallamshire Hospital, Sheffield, UK.
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Cioffi GA. Three Common Assumptions About Ocular Blood Flow and Glaucoma. Surv Ophthalmol 2001; 45 Suppl 3:S325-31; discussion S332-4. [PMID: 11377457 DOI: 10.1016/s0039-6257(01)00199-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Although substantial indirect evidence exists to link altered ocular blood flow to glaucoma, it must be remembered that the validity of investigations in this area depends on acceptance of three basic assumptions: 1) ischemia directly causes or increases the susceptibility of the optic nerve to glaucomatous damage; 2) optic nerve vascular anatomy and physiology allows identification of the critical vascular beds in optic nerve disease; and 3) current measurement techniques provide the ability to monitor important vascular beds. The hypotheses underlying these assumptions are examined.
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Affiliation(s)
- G A Cioffi
- Discoveries in Sight, Devers Eye Institute, Portland, OR 97210, USA
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Abstract
Vascular disorders of the anterior optic nerve, historically, have been described as potential etiologic factors in the development of glaucomatous optic neuropathy. During the past several decades, clinical and experimental evidence of the involvement of vascular aberrations as a potential causative factor or associated risk factor have increased. However, the direct evidence that optic nerve ischemia contributes to glaucomatous optic neuropathy remains limited. Several questions about our current knowledge arise. Can ischemia alone or in combination with other factors cause glaucomatous optic neuropathy? Does our current knowledge of the vascular anatomy and physiology of the optic nerve allow us to understand vascular changes observed in individuals with glaucoma? Can we rely on current measurement techniques to assess and monitor the vascular beds of the optic nerve? This article summarizes the complex nature of the microcirculation in the anterior optic nerve, discusses the possible contribution of vascular factors in the development of glaucoma optic neuropathy, and examines the measurement techniques used in current studies.
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Affiliation(s)
- G A Cioffi
- Devers Eye Institute, Portland, OR 97210, USA
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Holló G. Scanning laser Doppler flowmeter study of retinal and optic disk blood flow in glaucomatous patients. Am J Ophthalmol 1997; 123:859-60. [PMID: 9535643 DOI: 10.1016/s0002-9394(14)71148-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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