Journal List > J Korean Ophthalmol Soc > v.49(7) > 1008018

Il Kwon, Won Park, and Suk Chung: Retinal Nerve Fiber Layer Thickness Analysis in Early Glaucoma

Abstract

Purpose

To investigate the difference between superior and inferior peripapillary retinal nerve fiber layer (RNFL) thickness in early glaucoma patients who have RNFL defect in either superior quadrant or inferior quadrant and to determine if it can be useful to detect early glaucomatous change.

Methods

Eighty eight patients with early glaucoma who have RNFL defect in either the superior quadrant or the inferior quadrant as confirmed by red free photograph (40 eyes with normal standard automated perimetry and 48 eyes with early glaucomatous visual field loss) were divided into the superior RNFL defect group and the inferior RNFL defect group. The average RNFL thickness was measured in the superior and inferior quadrants using optical coherence tomography and the thickness differences between the superior and the inferior quadrants (S-I difference) were compared among early glaucoma eyes and 59 normal controls. Then, discriminative power of the S-I difference was assessed by area under ROC (AUROC).

Results

The average thickness of the RNFL showed a statistically significant difference between early glaucoma eyes and normal controls (P<0.05). S-I differences of the superior RNFL defect group and inferior RNFL defect group in preperimetric patients and in early perimetric patients were -20.5±16.4 µm and 15.0±14.2 µm, -24.0±17.2 µm and 18.4±16.7 µm, respectively, which were significantly greater than that of the normal control group (-8.2±17.1 µm). AUROC of S-I difference in the superior and inferior defect groups of preperimetric patients were 0.691, 0.872, respectively.

Conclusions

The difference in RNFL thickness between the superior and inferior quadrants (S-I difference) in early glaucoma patients was larger than in normal controls. We expect that this parameter of RNFL analysis using OCT can be useful in detecting early glaucoma.

References

1. Quigley HA, Addicks EM, Green WR. Optic nerve damage in human glaucoma. III:quantitiative correlation of nerve fiber loss and visual field defect in glaucoma, ischemic neuropathy, papilledema, and toxic neuropathy. Arch Ophthalmol. 1982; 100:135–46.
2. Quigley HA, Dunkelberger GR, Green WR. Retinal ganglion cell atrophy correlated with automated perimetry in human eyes with glaucoma. Am J Ophthalmol. 1989; 107:453–64.
crossref
3. Kerrigan-Baumrind LA, Quigley HA, Pease ME. . Number of ganglion cells in glaucoma eyes compared with threshold visual field tests in the same persons. Invest Ophthalmol Vis Sci. 2000; 41:741–8.
4. Greaney MJ, Hoffman DC, Garway-Heath DF. . Comparison of optic nerve imaging methods to distinguish normal eyes from those with glaucoma. Invest Ophthlamol Vis Sci. 2002; 43:140–5.
5. Bagga H, Feuer WJ, Greenfield DS. Detection of psychophysical and structural injury in eyes with glaucomatous optic neuropathy and normal standard automated perimetry. Arch Ophthalmol. 2006; 124:169–76.
crossref
6. Kwok HM, Vincent WL, Kwok FS. Retinal nerve fiber layer measurement by optical coherence tomography in glaucoma suspects with short-wavelength perimetry abnormalities. J Glaucoma. 2003; 12:45–9.
7. Quigley HA, Dunkelberger GR, Green WR. Retinal ganglion cell atrophy correlated with automated perimetry in human eyes with glaucoma. Am J Ophthalmol. 1989; 107:453–64.
crossref
8. Chi QM, Tomita G, Inazumi K. . Evaluation of the effect of aging on the retinal nerve fiber layer thickness using scanning laser polarimetry. J Glaucoma. 1995; 406:644–9.
crossref
9. Williams ZY, Schuman JS, Gamell L. . Optical coherence tomography measurement of nerve fiber layer thickness and the likelihood of a visual field defect. Am J Ophthalmol. 2002; 134:538–46.
10. Da pozzo S, Iacono P, Marchesan R. . The effect of aging on retinal nerve fibre layer thickness: an evaluation by scanning laser polarimetry with variable corneal compensation. Acta Ophthalmol Scand. 2006; 84:375–9.
11. Anderson DR. Automated static perimetry. 1992. 1st ed. St. Louis: Mosby Year Book Inc;p. 80.
12. Airaksinen PJ, Drance SM, Douglas GR. . Diffuse and localized nerve fiber loss in glaucoma. Am J Ophthalmol. 1984; 98:566–71.
crossref
13. Sommer A, Katz J, Quigley HA. . Clinically detectable nerve fiber atrophy precedes the onset of glaucomatous field loss. Arch Ophthalmol. 1991; 109:77–83.
crossref
14. Johnson CA, Sample PA, Zangwill LM. . Structure and Function Evaluation (SAFE):II. Comparison of optic disc and visual field characteristics. Am J Ophthalmol. 2003; 135:148–54.
15. Hwang JM, Kim TW, Park KH. . Correlation between topographic profiles of localized retinal nerve fiber layer defects as determined by optical coherence tomography and red-free fundus photography. J Glaucoma. 2006; 15:223–8.
crossref
16. Kim TW, Park KH, Kim DM. . Ability of Stratus OCT to identify localized retinal nerve fiber layer defects in patients with normal standard automated perimetry results. Invest Ophthalmol Vis Sci. 2007; 48:1635–41.
crossref
17. Badlani V, Shahidi M, Shakoor A. . Nerve fiber layer thickness in glaucoma patients with asymmetric hemifield visual field loss. J Glaucoma. 2006; 15:275–80.
crossref
18. Kim JG, Ko MK, Choe JK. Neuroretinal rim area and pattern of neuroretinal rim loss in glaucomatous optic disc. J Korea Ophthalmol Soc. 1994; 35:565–71.
19. Budenz DL, Michael A, Chang RT. . Sensitivity and specificity of the stratus OCT for perimetric glaucoma. Ophthalmology. 2005; 112:3–9.
20. Kim TW, Park UC, Park KH. . Ability of stratus OCT to identify localized retinal nerve fiber layer defects in patients with normal standard automated perimetry results. Invest Ophthalmol Vis Sci. 2007; 48:1635–41.
crossref

Figure 1.
ROC (receiver operator characteristic) curve of the each parameter in the superior RNFL defect group.
jkos-49-1101f1.tif
Figure 2.
ROC curve of the each parameter in the inferior RNFL defect group.
jkos-49-1101f2.tif
Table 1.
Characteristics in each group
Preperimetric glaucoma
Early perimetric glaucoma
Control p-value
Sup* Inf* Sup* Inf*
Number (eye) 14 26 21 27 59
Sex (M/F) 7/7 14/12 11/10 15/12 29/30
Age (year) 54±9.1 48.2±14 54.2±16.5 52.2±14.3 47.6±9.1 0.115
SE(D) -0.97±2.9 -1.9±3.1 -1.9±2.3 -1.2±2.9 -0.66±1.2 0.065

* Location of RNFL defect;

SE=spherical equivalent. (ANOVA, p<0.05)

Table 2.
RNFL thickness of preperimetric glaucoma eyes and control eyes
Sup* p-value Inf* p-value Control
Avg (µm) 96.8±10.9 0.000 98.9±11.3 0.000 109.9±7.4
Sup (µm) 112.8±19.3 0.000 128.2±15.2 0.021 136.2±14.0
Inf (µm) 133.3±15.5 0.008 113.2±18.3 0.000 144.2±12.9
Sup-Inf (µm) -20.5±16.4 0.017 15.0±14.2 0.000 -8.2±17.1

* Location of RNFL defect;

Statistical significance in RNFL thickness compared to control group. (Student t-test, p<0.05)

Table 3.
RNFL thickness of early perimetric glaucoma eyes and control eyes
Sup* p-value Inf* p-value Control
Avg (µm) 87.3±12.3 0.000 91.1±11.6 0.000 109.9±7.4
Sup (µm) 94.1±18.6 0.000 119.6±16.8 0.000 136.2±14.0
Inf (µm) 118.1±21.8 0.000 101.2±18.8 0.000 144.2±12.9
Sup-Inf (µm) -24.0±17.2 0.000 18.4±16.7 0.000 -8.2±17.1

* Location of RNFL defect;

Statistical significance in RNFL thickness compared to control group. (Student t-test, p<0.05)

Table 4.
Statistical analysis of RNFL thickness between preperimetric and early perimetric glaucoma according to the location of RNFL defect
P-value Sup* Inf
Avg 0.025 0.017
Sup 0.007 0.057
Inf 0.022 0.023
Sup-Inf 0.547 0.433

* Sup=superior RNFL defect group;

Inf=inferior RNFL defect group. (Student t-test, P<0.05)

Table 5.
Area under ROC, sensitivity, specificity and cut-off value to separate normal subjects from patients with preperimetric glaucoma
ROC area Sensitivity (%) Specificity (%) Cut-off value (µm)
Sup defect group
Avg 0.811 78.6 93.2 99.15
Sup 0.825 71.4 91.5 119.5
Inf 0.710 64.3 91.4 134
Sup-Inf 0.691 57.1 71.2 -16.0

Inf defect group
Avg 0.786 76.9 79.7 104.6
Sup 0.648 46.2 81.4 125.5
Inf 0.903 80.8 93.2 123.5
Sup-Inf 0.872 88.5 79.7 3.5
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