1
|
Michelessi M, Riva I, Martini E, Figus M, Frezzotti P, Agnifili L, Manni G, Quaranta L, Miglior S, Posarelli C, Fazio S, Oddone F. Macular versus nerve fibre layer versus optic nerve head imaging for diagnosing glaucoma at different stages of the disease: Multicenter Italian Glaucoma Imaging Study. Acta Ophthalmol 2019; 97:e207-e215. [PMID: 30338652 DOI: 10.1111/aos.13930] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 09/02/2018] [Indexed: 02/07/2023]
Abstract
PURPOSE To compare the diagnostic accuracy of minimum rim width (MRW), peripapillary retinal nerve fibre layer (pRNFL) and multilayered macular analysis by Spectralis SD-OCT (Heidelberg Engineering, Germany) in discriminating perimetric glaucoma at different stages of the disease from healthy eyes. METHODS In this multicentre, prospective, evaluation of diagnostic tests study, multilayered macular analysis and MRW and pRNFL were obtained from one eye of 197 glaucoma (76 early, 68 moderate and 53 advanced) and of 83 healthy controls from the Multicenter Italian Glaucoma Imaging Study (MIGIS). The reference standard for classifying eyes as glaucomatous and for staging the disease was the visual field. The main outcome measures were area under the ROC curve (AUC) and sensitivity at fixed specificity (95%). RESULTS Average MRW and average pRNFL showed the highest and similar diagnostic accuracy in both the whole study population (AUC 0.968 and 0.939) and early glaucoma (AUC 0.956 and 0.929). Among the macular parameters, the three innermost retinal layers combined as the Ganglion Cell Complex provided the highest diagnostic accuracy (AUC 0.931) in the whole population, which was statistically similar to that of average pRNFL but inferior to that of average MRW. Compared to both average MRW and pRNFL, all macular parameters showed statistically significant lower accuracy in early glaucoma, but accuracy in moderate and advanced glaucoma showed no statistically significant differences among three protocols. CONCLUSION The diagnostic accuracy of MRW, pRNFL and macular analysis by Spectralis SD-OCT is overall good. MRW and pRNFL analysis performs statistically and clinically better than macular analysis to discriminate early glaucoma from healthy eyes.
Collapse
Affiliation(s)
| | | | | | - Michele Figus
- Department of Surgical, Medical, Molecular Pathology and of Critical Area University of Pisa Pisa Italy
| | - Paolo Frezzotti
- Department of Medicine, Surgery and Neuroscience University of Siena Siena Italy
| | - Luca Agnifili
- Ophthalmology Clinic Department of Medicine and Aging Science University G. d'Annunzio of Chieti‐Pescara Chieti Italy
| | - Gianluca Manni
- IRCCS – Fondazione Bietti Rome Italy
- DSCMT University of Rome, Tor Vergata Rome Italy
| | - Luciano Quaranta
- Department of Medical and Surgical Specialties Radiological Sciences and Public Health University of Brescia Brescia Italy
| | - Stefano Miglior
- Department of Ophthalmology University Bicocca of Milan Milan Italy
| | - Chiara Posarelli
- Department of Surgical, Medical, Molecular Pathology and of Critical Area University of Pisa Pisa Italy
| | - Stefano Fazio
- Department of Medicine, Surgery and Neuroscience University of Siena Siena Italy
| | | |
Collapse
|
2
|
Dong ZM, Wollstein G, Schuman JS. Clinical Utility of Optical Coherence Tomography in Glaucoma. Invest Ophthalmol Vis Sci 2017; 57:OCT556-67. [PMID: 27537415 PMCID: PMC4991023 DOI: 10.1167/iovs.16-19933] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Optical coherence tomography (OCT) has established itself as the dominant imaging modality in the management of glaucoma and retinal diseases, providing high-resolution visualization of ocular microstructures and objective quantification of tissue thickness and change. This article reviews the history of OCT imaging with a specific focus on glaucoma. We examine the clinical utility of OCT with respect to diagnosis and progression monitoring, with additional emphasis on advances in OCT technology that continue to facilitate glaucoma research and inform clinical management strategies.
Collapse
Affiliation(s)
- Zachary M Dong
- University of Pittsburgh Medical Center (UPMC) Eye Center Eye and Ear Institute, Department of Ophthalmology, University of Pittsburgh School of Medicine, Ophthalmology and Visual Science Research Center, Pittsburgh, Pennsylvania, United States
| | - Gadi Wollstein
- University of Pittsburgh Medical Center (UPMC) Eye Center Eye and Ear Institute, Department of Ophthalmology, University of Pittsburgh School of Medicine, Ophthalmology and Visual Science Research Center, Pittsburgh, Pennsylvania, United States 2Departmen
| | - Joel S Schuman
- University of Pittsburgh Medical Center (UPMC) Eye Center Eye and Ear Institute, Department of Ophthalmology, University of Pittsburgh School of Medicine, Ophthalmology and Visual Science Research Center, Pittsburgh, Pennsylvania, United States 2Departmen
| |
Collapse
|
3
|
Dong ZM, Wollstein G, Wang B, Schuman JS. Adaptive optics optical coherence tomography in glaucoma. Prog Retin Eye Res 2017; 57:76-88. [PMID: 27916682 PMCID: PMC5350038 DOI: 10.1016/j.preteyeres.2016.11.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 11/14/2016] [Accepted: 11/19/2016] [Indexed: 02/07/2023]
Abstract
Since the introduction of commercial optical coherence tomography (OCT) systems, the ophthalmic imaging modality has rapidly expanded and it has since changed the paradigm of visualization of the retina and revolutionized the management and diagnosis of neuro-retinal diseases, including glaucoma. OCT remains a dynamic and evolving imaging modality, growing from time-domain OCT to the improved spectral-domain OCT, adapting novel image analysis and processing methods, and onto the newer swept-source OCT and the implementation of adaptive optics (AO) into OCT. The incorporation of AO into ophthalmic imaging modalities has enhanced OCT by improving image resolution and quality, particularly in the posterior segment of the eye. Although OCT previously captured in-vivo cross-sectional images with unparalleled high resolution in the axial direction, monochromatic aberrations of the eye limit transverse or lateral resolution to about 15-20 μm and reduce overall image quality. In pairing AO technology with OCT, it is now possible to obtain diffraction-limited resolution images of the optic nerve head and retina in three-dimensions, increasing resolution down to a theoretical 3 μm3. It is now possible to visualize discrete structures within the posterior eye, such as photoreceptors, retinal nerve fiber layer bundles, the lamina cribrosa, and other structures relevant to glaucoma. Despite its limitations and barriers to widespread commercialization, the expanding role of AO in OCT is propelling this technology into clinical trials and onto becoming an invaluable modality in the clinician's arsenal.
Collapse
Affiliation(s)
- Zachary M Dong
- University of Pittsburgh Medical Center (UPMC) Eye Center, Eye and Ear Institute, Department of Ophthalmology, University of Pittsburgh School of Medicine, Ophthalmology and Visual Science Research Center, Pittsburgh, PA, United States.
| | - Gadi Wollstein
- New York University (NYU) Langone Eye Center, NYU Langone Medical Center, Department of Ophthalmology, NYU School of Medicine, New York, NY, United States.
| | - Bo Wang
- University of Pittsburgh Medical Center (UPMC) Eye Center, Eye and Ear Institute, Department of Ophthalmology, University of Pittsburgh School of Medicine, Ophthalmology and Visual Science Research Center, Pittsburgh, PA, United States.
| | - Joel S Schuman
- New York University (NYU) Langone Eye Center, NYU Langone Medical Center, Department of Ophthalmology, NYU School of Medicine, New York, NY, United States; Department of Electrical and Computer Engineering, New York University Tandon School of Engineering, Brooklyn, NY, United States.
| |
Collapse
|
4
|
Hong SW, Lee SB, Jee DH, Ahn MD. Interocular retinal nerve fiber layer thickness difference in normal adults. PLoS One 2015; 10:e0116313. [PMID: 25679786 PMCID: PMC4332477 DOI: 10.1371/journal.pone.0116313] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 12/08/2014] [Indexed: 11/29/2022] Open
Abstract
Purpose To determine the interocular retinal nerve fiber layer (RNFL) thickness difference of normal subjects. Methods Both eyes of 230 normal adults received peripapillary RNFL thickness measurements using OCT. The effect of ocular cyclotorsion on the RNFL thickness profile was mathematically corrected. The fractional and absolute interocular RNFL thickness differences at 256 points of peripapillary area were calculated. We divided the subjects into 3 groups according to the locations of superior and inferior peak thickness, respectively, and compared the interocular RNFL thickness differences between the subgroups. Results The fractional interocular RNFL thickness difference exhibited smaller regional variations than the absolute interocular difference. The means of fractional interocular differences were 0.100 ± 0.077 in the temporal half area and 0.146 ± 0.105 in the nasal half area, and the tolerance limits for the 95th and 99th distributions were about 0.246 and 0.344 in the temporal half area and 0.293 and 0.408 in the nasal half area, respectively. The fractional interocular differences of subgroups classified by the locations of superior and inferior peak RNFL thickness showed difference at smaller areas than the absolute interocular differences (19 and 8 points versus 49 and 23 points, respectively). Conclusion Glaucoma can be strongly suspected, if interocular fractional RNFL thickness difference is over 25% at 5 consecutive points or over 35% at 3 consecutive points in the temporal half area. The fractional interocular comparison is a better diagnostic approach because the fractional interocular RNFL thickness difference is less influenced by the locations of peak RNFL thickness.
Collapse
Affiliation(s)
- Seung Woo Hong
- Department of Ophthalmology and Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea
- Department of Ophthalmology, Armed Forces Capital Hospital of Korea, Seongnam city, Gyeonggi province, Korea
| | - Seung Bum Lee
- Department of Ophthalmology and Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Dong-hyun Jee
- Department of Ophthalmology and Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Myung Douk Ahn
- Department of Ophthalmology and Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea
- * E-mail:
| |
Collapse
|
5
|
Meier KL, Greenfield DS, Hilmantel G, Kahook MY, Lin C, Rorer EM, Singh K, Tarver ME, Weinreb RN, Eydelman MB, Liebmann JM. Special Commentary: Food and Drug Administration and American Glaucoma Society Co-sponsored Workshop. Ophthalmology 2014; 121:2116-23. [DOI: 10.1016/j.ophtha.2014.05.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 05/22/2014] [Accepted: 05/22/2014] [Indexed: 11/29/2022] Open
|
6
|
Interocular Retinal Nerve Fiber Layer Thickness Symmetry Value in Normal Young Adults. J Glaucoma 2014; 23:e125-31. [DOI: 10.1097/ijg.0000000000000032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
7
|
Chandra A, Bandyopadhyay AK, Bhaduri G. A comparative study of two methods of optic disc evaluation in patients of glaucoma. Oman J Ophthalmol 2013; 6:103-7. [PMID: 24082669 PMCID: PMC3779406 DOI: 10.4103/0974-620x.116643] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
INTRODUCTION Glaucoma is a progressive disorder and requires serial evaluation in order to monitor disease progression and optimize therapy. OBJECTIVE The objective of this study was to determine the correlation between each of cup/disc (C/D) ratio and the disc damage likelihood scale (DDLS) with retinal nerve fiber layer (RNFL) and global indices in Humphrey field analyzer II (HFA II). DESIGN Cross-sectional study. MATERIALS AND METHODS A total of 50 patients diagnosed with primary open angle glaucoma were examined to grade DDLS score and C/D ratio. The average (avg) RNFL was obtained using the Fast RNFL protocol on optical coherence tomography (OCT) (4.0.2 Carl Zeiss). HFA II Swedish Interactive Threshold Algorithm Standard 24-2 visual fields were obtained within 1 month of clinical examination. The correlation of C/D ratio with avg RNFL thickness, Mean deviation and Pattern standard deviation was calculated by Pearson correlation coefficient (r). Similar coefficients were obtained for DDLS. RESULTS The P value for the difference in the r between C/D ratio with RNFL (-0.628) and DDLS with RNFL (-0.8369) was significant (P < 0.01) when correlation of C/D, DDLS with RNFL was considered. CONCLUSION The DDLS shows stronger correlation with structural changes in OCT than C/D ratio. The disc diameter and rim width increases the value of clinical optic disc examination.
Collapse
Affiliation(s)
- Anuradha Chandra
- Department of Ophthalmology, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | | | | |
Collapse
|
8
|
Wu H, de Boer JF, Chen TC. Diagnostic capability of spectral-domain optical coherence tomography for glaucoma. Am J Ophthalmol 2012; 153:815-826.e2. [PMID: 22265147 DOI: 10.1016/j.ajo.2011.09.032] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 09/28/2011] [Accepted: 09/28/2011] [Indexed: 11/29/2022]
Abstract
PURPOSE To determine the diagnostic capability of spectral-domain optical coherence tomography in glaucoma patients with visual field defects. DESIGN Prospective, cross-sectional study. METHODS SETTINGS Participants were recruited from a university hospital clinic. STUDY POPULATION One eye of 85 normal subjects and 61 glaucoma patients with average visual field mean deviation of -9.61 ± 8.76 dB was selected randomly for the study. A subgroup of the glaucoma patients with early visual field defects was calculated separately. OBSERVATION PROCEDURES Spectralis optical coherence tomography (Heidelberg Engineering, Inc) circular scans were performed to obtain peripapillary retinal nerve fiber layer (RNFL) thicknesses. The RNFL diagnostic parameters based on the normative database were used alone or in combination for identifying glaucomatous RNFL thinning. MAIN OUTCOME MEASURES To evaluate diagnostic performance, calculations included areas under the receiver operating characteristic curve, sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio. RESULTS Overall RNFL thickness had the highest area under the receiver operating characteristic curve values: 0.952 for all patients and 0.895 for the early glaucoma subgroup. For all patients, the highest sensitivity (98.4%; 95% confidence interval, 96.3% to 100%) was achieved by using 2 criteria: ≥ 1 RNFL sectors being abnormal at the < 5% level and overall classification of borderline or outside normal limits, with specificities of 88.9% (95% confidence interval, 84.0% to 94.0%) and 87.1% (95% confidence interval, 81.6% to 92.5%), respectively, for these 2 criteria. CONCLUSIONS Statistical parameters for evaluating the diagnostic performance of the Spectralis spectral-domain optical coherence tomography were good for early perimetric glaucoma and were excellent for moderately advanced perimetric glaucoma.
Collapse
Affiliation(s)
- Huijuan Wu
- Glaucoma Service, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | | | | |
Collapse
|
9
|
Marschall S, Sander B, Mogensen M, Jørgensen TM, Andersen PE. Optical coherence tomography-current technology and applications in clinical and biomedical research. Anal Bioanal Chem 2011; 400:2699-720. [PMID: 21547430 DOI: 10.1007/s00216-011-5008-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 03/25/2011] [Accepted: 04/08/2011] [Indexed: 12/21/2022]
Abstract
Optical coherence tomography (OCT) is a noninvasive imaging technique that provides real-time two- and three-dimensional images of scattering samples with micrometer resolution. By mapping the local reflectivity, OCT visualizes the morphology of the sample. In addition, functional properties such as birefringence, motion, or the distributions of certain substances can be detected with high spatial resolution. Its main field of application is biomedical imaging and diagnostics. In ophthalmology, OCT is accepted as a clinical standard for diagnosing and monitoring the treatment of a number of retinal diseases, and OCT is becoming an important instrument for clinical cardiology. New applications are emerging in various medical fields, such as early-stage cancer detection, surgical guidance, and the early diagnosis of musculoskeletal diseases. OCT has also proven its value as a tool for developmental biology. The number of companies involved in manufacturing OCT systems has increased substantially during the last few years (especially due to its success in opthalmology), and this technology can be expected to continue to spread into various fields of application.
Collapse
Affiliation(s)
- Sebastian Marschall
- DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, Roskilde, Denmark
| | | | | | | | | |
Collapse
|
10
|
The location of the inferior and superior temporal blood vessels and interindividual variability of the retinal nerve fiber layer thickness. J Glaucoma 2010; 19:158-66. [PMID: 19661824 DOI: 10.1097/ijg.0b013e3181af31ec] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To determine if adjusting for blood vessel (BV) location can decrease the intersubject variability of retinal nerve fiber layer (RNFL) thickness measured with optical coherence tomography (OCT). SUBJECTS AND METHODS One eye of 50 individuals with normal vision was tested with OCT and scanning laser polarimetry (SLP). The SLP and OCT RNFL thickness profiles were determined for a peripapillary circle 3.4 mm in diameter. The midpoints between the superior temporal vein and artery (STva) and the inferior temporal vein and artery (ITva) were determined at the location where the vessels cross the 3.4 mm circle. The average OCT and SLP RNFL thicknesses for quadrants and arcuate sectors of the lower and upper optic disc were obtained before and after adjusting for BV location. This adjustment was carried out by shifting the RNFL profiles based upon the locations of the STva and ITva relative to the mean locations of all 50 individuals. RESULTS Blood vessel locations ranged over 39 (STva) and 33 degrees (ITva) for the 50 eyes. The location of the leading edge of the OCT and SLP profiles was correlated with the location of the BVs for both the superior [r=0.72 (OCT) and 0.72 (SLP)] and inferior [r=0.34 and 0.43] temporal vessels. However, the variability in the OCT and SLP thickness measurements showed little change due to shifting. After shifting, the difference in the coefficient of variation ranged from -2.1% (shifted less variable) to +1.7% (unshifted less variable). CONCLUSIONS The shape of the OCT and SLP RNFL profiles varied systematically with the location of the superior and inferior superior veins and arteries. However, adjusting for the location of these major temporal BVs did not decrease the variability for measures of OCT or SLP RNFL thickness.
Collapse
|
11
|
Li S, Wang X, Wu G, Fu J, Li S, Wan X, Wang N. Comparison of two retinal nerve fibre layer thickness measurement patterns of RTvue optical coherence tomography. Clin Exp Ophthalmol 2010; 39:222-9. [PMID: 20973891 DOI: 10.1111/j.1442-9071.2010.02438.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND To evaluate the agreement and repeatability between operator-dependent centring and automatic centring retinal nerve fibre layer thickness measurement patterns (RNFL3.45 and NHM4) of RTvue optical coherence tomography in normal and glaucomatous eyes. DESIGN Cross-sectional observational study. PARTICIPANTS A total of 153 eyes from 149 normal subjects and subjects with glaucoma were analysed. METHODS The retinal nerve fibre layer thickness was measured using RNFL3.45 and NHM4 three times on the same day to determine the repeatability and agreement between the two scan patterns. MAIN OUTCOME MEASURES Student's paired t-testing, intra-class correlation coefficient, coefficient of variation, test-retest viability, Pearson's correlation coefficient and Bland-Altman analysis of retinal nerve fibre layer thickness measurements. RESULTS The difference between RNFL3.45 and NHM4 measurements was statistically significant by paired t-testing (P=0.003) only in severe glaucoma group. The Pearson's correlation test showed a high degree of correlation of the mean retinal nerve fibre layer thickness (r=0.949). Bland-Altman plots showed that the differences between RNFL3.45 and NHM4 were smaller at thicker retinal nerve fibre layer values, but larger at thinner retinal nerve fibre layer values. The intra-class correlation coefficient for RNFL3.45 (and lower 95% confidence interval) in normal and glaucomatous eyes was 0.990 (0.985 confidence interval) and 0.997 (0.995 confidence interval), respectively. The intra-class correlation coefficient for NHM4 in normal and glaucomatous eyes was 0.989 (0.983 confidence interval) and 0.995 (0.992 confidence interval), respectively. The test-retest variability for RNFL3.45 and NHM4 ranged from 3.98 to 9.75µm in normal eyes, and from 4.10 to 13.34µm in glaucomatous eyes. CONCLUSION Measurements of retinal nerve fibre layer thickness by RNFL3.45 and NHM4 are in good agreement.
Collapse
Affiliation(s)
- Shuning Li
- Beijing Ophthalmology and Visual Science Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University Ophthalmology Department of Nanjing Tongren Hospital, Nanjing, China
| | | | | | | | | | | | | |
Collapse
|
12
|
Shin JH, Yoo YC, Park KH. Usefulness of Table Parameters of Stratus OCT in Detection of Localized Retinal Nerve Fiber Layer Defects. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2010. [DOI: 10.3341/jkos.2010.51.9.1237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Jung Hwan Shin
- Department of Ophthalmology, Kang Dong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Young Cheol Yoo
- Department of Ophthalmology, Kang Dong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Ki Ho Park
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea
| |
Collapse
|
13
|
|
14
|
An analysis of normal variations in retinal nerve fiber layer thickness profiles measured with optical coherence tomography. J Glaucoma 2008; 17:333-40. [PMID: 18703941 DOI: 10.1097/ijg.0b013e3181650f8b] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE To assess the normal variations in retinal nerve fiber layer (RNFL) thickness measured with optical coherence tomography (OCT). SUBJECTS AND METHODS Both eyes of 48 individuals (age 56.4+/-9.5 y) with normal vision and refractive errors between +/-6.0 D were tested with the fast RNFL scan protocol of the OCT3 (Zeiss Meditech). Their 256-point RNFL profiles were exported for analysis. The location and peak amplitude of the maxima of the RNFL profiles were measured. Intersubject and interocular variations were assessed with a coefficient of determination, R2. An R2 of 1.0 indicated that the average profile from all 48 individuals (or of the 2 eyes) accounted for 100% of the variation of an individual eye's profile. RESULTS The R2 for the interocular comparison was good, with averages of 0.91+/-0.07 (right eye) and 0.92+/-0.05 (left eye). The R2 for the comparison of the individual's profile to the mean group profile was only 0.61+/-0.29 (right eye) and 0.65+/-0.24 (left eye), with 27% of the R2 values below 0.5. Even after normalizing each individual's profile by its mean, R2 was only 0.75+/-0.16 (0.75+/-0.16) for the right (left) eye. The location of the peaks for the right (left) eye ranged over 91 degrees (88 degrees) for the superior peak and over 64 degrees (66 degrees) for the inferior peak. The range of peak amplitudes for the right (left) eye spanned a factor of 1.7 (1.8) and 2.0 (1.7) for the superior and inferior peaks, respectively. CONCLUSIONS There was a wide variation in the amplitude and shape of the individual RNFL profiles. However, the RNFL profiles of the 2 eyes of an individual were extremely similar. Adding an interocular comparison with OCT RNFL tests should help identify some false positives.
Collapse
|
15
|
Hougaard JL, Heijl A, Bengtsson B. Glaucomatous retinal nerve fibre layer defects may be identified in Stratus OCT images classified as normal. Acta Ophthalmol 2008; 86:569-75. [PMID: 18577195 DOI: 10.1111/j.1755-3768.2008.01263.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
PURPOSE We aimed to compare the retinal nerve fibre layer (RNFL) in different Stratus optical coherence tomography (OCT) images in glaucoma eyes with RNFL thickness values within normal limits. METHODS We studied the Stratus OCT high-resolution standard protocol for assessment of peripapillary RNFL thickness. The four glaucoma eyes presented (with reproducible visual field defects, mean deviations from -3.49 dB to -0.49 dB and structural loss on RNFL and/or disc photography) had results within the 95% normal limits for all OCT parameters (full circle, quadrant or clock hour mean RNFL thickness). We qualitatively compared the RNFL in pseudo-colour and grey-scale images defined by the Stratus OCT software with what appeared to be the RNFL when not defined automatically (and in raw data OCT images). RESULTS A localized RNFL defect was identified in conventional 495-nm RNFL photographs in all four patients. Obviously, in these selected eyes, the atrophy was not picked up by the OCT RNFL border algorithm, and at the corresponding location a localized RNFL atrophy (narrowing of the high signal intensity RNFL) was either not or just barely detectable in pseudo-colour OCT. However, defects seemed to be present in OCT grey-scale and raw data images in all four eyes. CONCLUSIONS Our observations suggest that OCT images obtained in glaucoma eyes that are misclassified by the standard statistical analyses of Stratus OCT may contain information indicating RNFL defects. Thus, the current diagnostic ability of OCT in glaucoma can probably be extended.
Collapse
Affiliation(s)
- Jesper Leth Hougaard
- Department of Clinical Sciences, Ophthalmology, Malmö University Hospital, Lund University, Malmö, Sweden.
| | | | | |
Collapse
|
16
|
|