빛간섭단층촬영을이용한정상, 녹내장의증, 초기녹내장에서의변수비교분석 1379
1380
Table 1. Criteria for each subject Enrolled group Criteria All subjects Best corrected visual acuity >0.5 Refractive error <4 diopter (Spherical equivalent) No history of systemic disease, trauma, and secondary causes of glaucoma No significant cataract or vitreous opacity Normal subject Intraocular pressure (IOP) 21 mmhg with repeated measure Normal finding on ocular examination Absence of glaucomatous optic neuropathy (GON) defined as vertical cup/disk asymmetry between fellow eyes of 0.2 or less cup/disk ratio of 0.6 or less Intact neural rim without peripapillary hemorrhages, notches, localized pallor, or RNFL (Retinal nerve fiber layer) defects Normal visual field defined as mean deviation and pattern standard deviation within 95% confidence limits Glaucoma hemifield test (GHT): within normal limit Glaucoma suspect Intraocular pressure (IOP) 21 mmhg with repeated measure Presence of glaucomatous optic neuropathy (GON) Normal visual field (GHT: within normal limit or borderline) Early glaucoma Glaucomatous optic neuropathy plus Glaucomatous visual field loss in the corresponding hemifield location Based on liberal criteria GHT : outside normal limit Mean deviation >-6dB in Humphrey field analyzer Enrolled group Criteria All subjects Best corrected visual acuity >0.5 Refractive error <4 diopter (Spherical equivalent) No history of systemic disease, trauma, and secondary causes of glaucoma No significant cataract or vitreous opacity Normal subject Intraocular pressure (IOP) 21 mmhg with repeated measure Normal finding on ocular examination Absence of glaucomatous optic neuropathy (GON) defined as vertical cup/disk asymmetry between fellow eyes of 0.2 or less cup/disk ratio of 0.6 or less Intact neural rim without peripapillary hemorrhages, notches, localized pallor, or RNFL (Retinal nerve fiber layer) defects Normal visual field defined as mean deviation and pattern standard deviation within 95% confidence limits Glaucoma hemifield test (GHT): within normal limit Glaucoma suspect Intraocular pressure (IOP) 21 mmhg with repeated measure Presence of glaucomatous optic neuropathy (GON) Normal visual field (GHT: within normal limit or borderline) Early glaucoma Glaucomatous optic neuropathy plus Glaucomatous visual field loss in the corresponding hemifield location Based on liberal criteria GHT: outside normal limit Mean deviation > -6dB in Humphrey field analyzer 1381
Table 2. Backgrounds of subjects Normal Glaucoma suspect Early glaucoma P value Number of patient 102 72 85 Age (years) 52.40±9.41 51.51±9.58 52.76±11.02.728 MD * (db) -1.76±.06-1.79±1.17-3.52±1.38.000 R.E. (diopter) -1.26±2.19-0.59±1.72-0.53±2.17.217 Cup/disk ratio 0.42±0.12 0.61±0.13 0.65±0.21.000 CCT (µm) 518.7±37.0 520.5±43.7 522.7±25.9.835 IOP (mmhg) 16.23±3.11 16.40±3.09 16.78±5.14.623 MD * : mean deviation. R.E. : refractive error. CCT : central corneal thickness. IOP : intraocular pressure. P value : statistical significance was tested by ANOVA. Table 3. Comparison of OCT measured optic nerve head (ONH) analysis parameter value among groups Measurement Normal Glaucoma suspect Early glaucoma P * vert. integrated rim vol. (mm 3 ) 0.27±0.16 0.22±0.13 0.18±0.14.000 horiz. Integrated Rim Area (mm 2 ) 1.62±0.20 1.60±0.21 1.39±0.24.000 rim area (mm 2 ) 1.54±0.35 1.44±0.33 1.20±0.45.000 cup/disk area ratio 0.42±0.14 0.51±0.13 0.55±0.16.000 cup/disk horiz. ratio 0.69±0.15 0.76±0.12 0.78±0.13.000 cup/disk vert. ratio 0.59±0.13 0.66±0.10 0.68±0.14.012 P * : ANOVA, Tuckey Kramer test was performed in normal, glaucoma suspect, and early glaucoma patient. : Normal group significantly different from early glaucoma and glaucoma suspect groups. : Early glaucoma group significantly different from normal and glaucoma suspect groups. 1382
Table 4. Comparison of OCT measured retinal nerve fiber layer (RNFL) thickness (µm) analysis parameter value among groups Measurement Normal Glaucoma Suspect Early Glaucoma P * P P P Average 104.2±9.7 103.6±9.6 92.8±14.5.000.938.000.000 Superior quadrant 126.7±14.0 125.8±15.4 114.3±19.4.000.922.000.000 Temporal quadrant 73.7±10.0 74.1±11.7 66.4±15.4.000.982.000.000 Inferior quadrant 137.1±16.8 131.6±16.0 118.9±22.2.000.140.000.000 Nasal quadrant 79.1±15.6 82.7±18.8 74.1±17.3.007.351.116.005 Smax 159.5±19.4 159.2±18.6 146.4±22.9.000.993.000.000 Imax 170.3±18.8 167.4±17.6 150.3±27.3.000.658.000.000 CH (Clock hour)12 130.4±20.2 129.1±23.4 117.3±24.5.000.928.000.003 CH11 133.1±19.4 132.7±22.0 119.5±27.8.000.994.000.001 CH10 86.4±14.5 86.2±16.8 77.7±19.6.001.995.001.005 CH9 (temporal) 60.3±10.4 60.8±10.9 55.4±14.9.008.961.021.019 CH8 77.7±14.9 78.4±15.7 68.9±18.4.000.965.001.001 CH7 142.4±20.2 137.3±23.4 121.1±30.3.000.381.000.000 CH6 (inferior) 149.1±22.9 144.2±20.6 130.9±27.4.000.384.000.002 CH5 118.9±23.3 117.9±23.0 106.2±21.7.000.955.001.004 CH4 77.9±16.8 81.1±16.0 72.9±18.6.001.451.111.008 CH3 (nasal) 64.7±13.9 66.1±16.5 61.3±16.0.125.820.290.125 CH2 91.1±22.6 93.2±22.0 84.0±22.3.024.819.081.030 CH1 117.1±19.4 115.4±19.0 102.5±25.6.000.868.000.001 Smax = Superior maximum; Imax = Inferior maximum. P * : ANOVA test was performed in normal, glaucoma suspect, and early glaucoma patient. P : Tuckey-Kramer test was performed in normal and glaucoma suspect. P : Tuckey-Kramer test was performed in normal and early glaucoma. P : Tuckey-Kramer test was performed in glaucoma suspect and early glaucoma. Smax = Superior maximum; Imax = Inferior maximum. Table 5. Area under the receiver operating characteristic (AUROC) curve, best combination of sensitivity/specificity with specificity 90% for the individual OCT parameters detecting early glaucoma Measurement AUROC Cut off value Sensitivity Specificity ONH * parameters horiz. integrated rim area 0.753 1.35 47.1% 92.0% rim area 0.729 1.11 45.9% 91.4% vert. integrated rim vol. 0.713 0.13 41.2% 91.4% RNFL thickness parameters Imax 0.718 144.5 37.6% 92.0% average thickness 0.759 92.5 50.6% 92.0% inferior 0.728 111.5 35.3% 93.7% ONH * = optic nerve head; RNFL = retinal nerve fiber layer; AUROC = area under the ROC curve; Imax = Inferior maximum. 1383
Table 6. Area under the receiver operating characteristic (AUROC) curve, best combination of sensitivity/specificity with specificity 80% for the individual OCT parameters detecting early glaucoma Measurement AUROC Cut off value Sensitivity Specificity ONH * parameters horiz. integrated rim area 0.753 1.42 51.8 83.9 rim area 0.729 1.56 55.3 81.6 vert. integrated rim vol. 0.713 0.14 48.2 84.5 RNFL thickness parameters Imax 0.718 154.5 54.1 81.0 average thickness 0.759 94.3 58.8 81.0 Inferior 0.728 120.5 50.6 81.6 ONH * = optic nerve head; RNFL = retinal nerve fiber layer; AUROC = area under the ROC curve; Imax = Inferior maximum. Figure 1. Receiver operating characteristic (ROC) curve of horizontal integrated rim width in control group and early glaucoma group. It has the best discriminating capability. Cut-off value 1.529 mm 2 yields high diagnostic value with sensitivity 72.9% and specificity 65.5%. Figure 2. Receiver operating characteristic (ROC) curve of average thickness in control group and early glaucoma group. It has the best discriminating capability among thickness parameters. Cut off value 92.17 µm yields high diagnostic value with sensitivity 49.4% and specificity 93.1%. 1384
1385
1) Gupta N, Weinerb RN. New definition of glaucoma. Curr Opin Ophthalmol 1997;8:38-41. 2) Quigley HA, Miller NR, George T. Clinical evaluation of nerve fiber layer atrophy as a indicator of glaucomatous optic nerve damage. Arch Ophthalmol 1980;98:1564-71. 3) Tuulonen A, Lehtola J, Airaksinen PJ. Nerve fiber layer defects with normal visual fields. Ophthalmology 1993;110:587-98. 4) Quigley HA, Dunkelberg GR, Green WR. Retinal ganglion cell atrophy correlated with automated perimetry in human eyes with glaucoma. Am J Ophthalmol 1989;107:453-64. 5) Sommer A, Katz J, Quigley HA, et al. Clinically detectable nerve fiber layer atrophy precedes the onset of glaucomatous field loss. Arch Ophthalmol 1991;109:77-83. 6) Schuman JS, Tamar PK, Hertzmark E, et al. Reproducibility of nerve fiber layer thickness measurements using optical coherence tomography. Ophthalmology 1996;103:1889-98. 7) Blumenthal EZ, Williams JM, Weinreb RN, et al. Reproducibility of nerve fiber layer thickness measurements by use of optical coherence tomography. Ophthalmology 2000;107: 2278-82. 8) Jonas JB, Schmidt AM, Muller-Bergh JA, et al. Human optic nerve fiber count and optic disc size. Invest Ophthalmol Vis Sci 1992;33:2012-8. 9) Varma R, Skaf M, Barrone E. Retinal nerve fiber layer thickness in normal human eyes. Ophthalmology 1996;103: 2114-9. 10) Tsai CS, Zangwill L, Gonzalez C, et al. Ethnic differences in optic nerve topography. J Glaucoma 1995;4:248-57. 11) Huang D, Swanson EA, Lin CP, et al. Optical coherence tomography. Science 1991;54:1178-81. 12) Schuman JS, Hee MR, Arya Av, et al. Optical coherence tomography of the human retina. Arch Ophthalmol 1995;113: 325-32. 13) Schuman JS, Hee MR, Puliafito CA, et al. Quantification of nerve fiber layer thickness in normal and glaucomatous eyes using optical coherence tomography. Arch Ophthalmol 1995;113:586-96. 14) Balazsi AG, Rootman J, Drance SM, et al. The effect of age on the nerve fiber population of the human optic nerve. Am J Ophthalmol 1984;97:760-6. 15) Johnson BM, Miao M, Sadun M. Age related decline of human optic nerve axon populations. Age 1987;10:5-9. 16) Hrynchak P, Hutchings N, Jones D, Simpson T. A comparison of cup-to-disc ratio measurement in normal subjects using optical coherence tomography image analysis of the optic nerve head and stereo fundus biomicroscopy. Ophthalmic Physiol Opt 2004;24:543-50. 17) Sim JO, Park CK. Optic nerve head analysis obtained by optical coherence tomography for the diagnosis of glaucoma in Koreans. J Korean Ophthalmol Soc 2004;45:1885-92. 18) Kanamori A, Nakamura M, Escano M, et al. Evaluation of the glaucomatous damage on retinal nerve fiber layer thickness measured by optical coherence tomography. Am J Ophthalmol 2003;135:513-20. 19) Zangwill LM, Bowd C, Berry CC, et al. Discriminating between normal and glaucomatous eye using the Heidelberg Retina Tomography, GDx Nerve Fiber Analyser, and Optical Coherence Tomographt. Arch Ophthalmol 2001;119:985-93. 20) Hoh ST, Greenfield DS, Mistberger A, et al. Optical coherence tomography and scanning laser polarimetry in normal, ocular hypertension and glaucomatous eyes. Am J Ophthalmol 2000;129:129-33. 1386
Optical Coherence Tomography Parameters of Normal, Glaucoma Suspect, and Early Glaucoma Patients Su Eun Park, M.D., Jin Kwon Jung, M.D., Ji Yong Jung, M.D., Song Hee Park, M.D. Department of Ophthalmology, College of Medicine, Soonchunhyang University, Seoul, Korea Purpose: The objective of this study is to compare optic nerve head (ONH) analysis parameters and retinal nerve fiber layer (RNFL) thickness parameters as measured by optical coherence tomography (OCT) among age-matched normal eyes, glaucoma-suspect eyes, and early glaucomatous eyes; and to determine the discriminating parameter best suited to distinguish early glaucoma in age-matched normal eyes and glaucomasuspect eyes. Methods: One hundred two normal eyes, 72 glaucoma-suspect eyes, and 85 eyes with early glaucoma that had been submitted to OCT and Humphrey field analysis were enrolled in this study. Optic nerve head analysis values and RNFL thickness values with OCT scans were compared among all groups. Sensitivity and specificity for the detection of early glaucoma were determined with a receiver operating characteristic (ROC) curve. Results: The best-suited parameters were determined to be from 0.637 to 0.753 in optic nerve head parameters and from 0.506 to 0.759 in RNFL thickness parameters calculated with the area under the ROC curve (AUROC). The average thickness for early glaucomatous eye (0.818) had the widest AUROC among all parameters. The sensitivity and specificity of RNFL thickness parameter were determined to be 49.4% and 93.1%, respectively, at the cut-off value 92.17 µm. Conclusions: Optic nerve head and RNFL thickness parameters measured with OCT have relatively high sensitivity and specificity for detecting early glaucomatous eyes. Furthermore, they may provide clinically relevant information for the detection of early glaucomatous damage and for monitoring glaucomatous changes. J Korean Ophthalmol Soc 48(10):1379-1387, 2007 Key Words: Optical coherence tomography, Optic disc parameter, Retinal nerve fiber layer thickness parameter 1387