Recently, the introduction of spectral-domain optical coherence tomography (SD-OCT) has enabled measurement of retinal thickness in the posterior pole in 64 sectors. SD-OCT was used to evaluate the diagnostic effectiveness in detecting glau-comatous abnormality of visual field sensitivity. A normal value for retinal thickness was determined and then compared in corre-sponding local sectors.
Thirty healthy controls and 30 glaucoma subjects were evaluated. Macular thickness values from the 4 adjacent square cells in an 8 × 8 posterior pole retinal thickness map were averaged for a mean retinal thickness (MRT) value. A normative database was prepared using the data from the healthy eyes of this study to determine the diagnostic criteria for MRT. If the MRT value was <5% (Criteria A) or <1% (Criteria B) of the normative database, it was considered to be abnormal. The abnormalities of the MRT value for each diagnostic criteria were compared with the visual field sensitivity results in the corresponding positions.
The concordance of abnormalities between MRT and visual field sensitivity at 16 measured points was low in both criteria A (Kappa value; −0.418∼0.429) and B (Kappa value; −0.363∼0.444). Based on the results of the visual field at each focal point, the sensitivities and specificities of MRT values using the 2 criteria ranged from 0% to 100%.
In this study, MRT values showed low correlation and diagnostic ability to detect decreased sensitivity of the visual field in corresponding points, when customized criteria derived from a normative database were applied.
The mean retinal thickness mapping corresponding to the visual field sensitivity. (A) A macular thickness map yielded by posterior pole asymmetry analysis of spectral domain optical coherence tomography is divided into 64 squares centered on the fovea. (B) We divided both the superior and inferior hemifields into 8 sectorsparts based on the horizontal raphe. Retinal thickness values of 4 ad-jacent square cells in the 8 χ8 grid of the posterior pole thickness map were averaged on the mean retinal thickness value. (C) Among the 52 test points of the central 24-2 pattern, the central 4 ×4 points corresponding to the 24° χ 24° posterior pole thickness map of the SPECTRALIS spectral-domain optical coherence tomography (SD-OCT) were considered. Same number between (B) and (C) indicated a pair of sector to undergo statistical analysis.
Demographic characteristics of study participants
Normal (n = 30) | Glaucoma (n = 30) | ||
---|---|---|---|
Age (years) | 52.03 ± 3.98 | 58.80 ± 4.12 | 0.55 |
Sex (M:F) | 13:17 | 20:10 | 0.07 |
Axial length (mm) | 23.83 ± 0.46 | 24.10 ± 0.58 | 0.30 |
Posterior pole retinal thickness (μm) | 294.15 ± 33.98 | 278.3 ± 41.03 | <0.01 |
Global index of standard automated perimetry | |||
MD (dB) | 0.34 ± 0.91 | -3.18 ± 5.89 | 0.03 |
PSD (dB) | 1.36 ± 0.10 | 3.92 ± 1.86 | <0.01 |
Values are presented as mean ± SD.
MD = median deviation; PSD = pattern standard deviation.
Independent
Chi-square test.
Mean retinal thickness of normal and glaucomatous eyes and cut off values in 16 sectors as well as average determined by SD-OCT
Sector | Control |
Glaucoma |
|||||
---|---|---|---|---|---|---|---|
Mean ± SD (μm) | Range (μm) | <5% (μm) | <1% (μm) | Mean ± SD (μm) | |||
Superior | 1 | 242.61 ± 8.57 | 230.25-254.50 | 224.08 | 217.25 | 231.76 ± 11.90 | <0.01 |
2 | 273.20 ± 9.99 | 259.50-288.75 | 251.66 | 248.75 | 258.14 ± 15.43 | <0.01 | |
3 | 292.49 ± 10.23 | 277.75-311.00 | 277.79 | 269.00 | 273.30 ± 18.02 | <0.01 | |
4 | 307.06 ± 12.75 | 287.25-334.00 | 287.25 | 284.50 | 274.10 ± 22.34 | <0.01 | |
5 | 268.84 ± 12.55 | 244.50-288.25 | 242.36 | 237.00 | 256.62 ± 13.43 | <0.01 | |
6 | 322.70 ± 13.50 | 294.50-338.00 | 293.55 | 291.75 | 306.86 ± 15.70 | <0.01 | |
7 | 336.46 ± 13.72 | 305.75-344.25 | 309.03 | 308.25 | 323.58 ± 18.77 | 0.04 | |
8 | 314.27 ± 13.20 | 289.75-333.25 | 289.90 | 282.00 | 299.94 ± 35.23 | 0.04 | |
Inferior | 1’ | 268.50 ± 9.89 | 227.50-321.25 | 249.15 | 245.00 | 224.07 ± 15.32 | <0.01 |
2’ | 269.24 ± 11.09 | 255.00-305.25 | 250.49 | 243.75 | 246.82 ± 14.75 | <0.01 | |
3’ | 287.96 ± 12.54 | 268.25-314.75 | 265.64 | 261.75 | 261.62 ± 19.69 | <0.01 | |
4’ | 304.00 ± 15.00 | 251.50-324.75 | 279.30 | 251.50 | 272.17 ± 27.47 | <0.01 | |
5’ | 269.78 ± 16.58 | 249.50-336.25 | 244.51 | 234.75 | 254.58 ± 13.72 | <0.01 | |
6’ | 324.26 ± 14.19 | 295.00-344.50 | 293.81 | 290.00 | 304.43 ± 19.28 | <0.01 | |
7’ | 331.91 ± 14.12 | 302.00-352.00 | 305.36 | 302.00 | 319.86 ± 21.19 | <0.01 | |
8’ | 313.50 ± 15.75 | 287.75-346.50 | 287.80 | 283.50 | 292.54 ± 20.52 | <0.01 |
Values are presented as mean ± SD.
SD-OCT = spectral-domain optical coherence tomography; SD = standard deviation.
Independent
Agreements of abnormal judgment between visual field sensitivity and mean retinal thickness, measurement in 16 tested sectors
Sector | Criteria A |
Criteria B |
|||
---|---|---|---|---|---|
Kappa value | Kappa value | ||||
Superior | 1 | -0.320 | 0.028 | 0.000 | 1.000 |
2 | -0.401 | 0.002 | -0.302 | 0.015 | |
3 | -0.418 | 0.014 | -0.363 | 0.015 | |
4 | 0.053 | 0.593 | 0.094 | 0.397 | |
5 | 0.02 | 0.894 | -0.064 | 0.506 | |
6 | 0.429 | 0.014 | 0.429 | 0.014 | |
7 | 0.132 | 0.356 | 0.132 | 0.356 | |
8 | 0.173 | 0.092 | 0.173 | 0.092 | |
Inferior | 1’ | -0.068 | 0.023 | -0.068 | 0.023 |
2’ | 0.110 | 0.351 | 0.187 | 0.170 | |
3’ | 0.233 | 0.102 | 0.268 | 0.070 | |
4’ | 0.170 | 0.190 | 0.444 | 0.014 | |
5’ | 0.379 | 0.037 | 0.380 | 0.008 | |
6’ | 0.286 | 0.088 | 0.000 | 1.000 | |
7’ | -0.119 | 0.377 | -0.105 | 0.513 | |
8’ | -0.017 | 0.900 | 0.020 | 0.894 |
If the average macular thickness value was <5% of that in the normative database, it was considered to be abnormal;
If the average macular thickness value was <1% of that in the normative database, it was considered to be abnormal.
The sensitivity and specificity of diagnostic criteria A and B of retinal thickness measurements to detect abnormal visual field sensitivity in 16 tested sectors
Sector | Criteria A |
Criteria B |
|||
---|---|---|---|---|---|
Sensitivity (%) | Specificity (%) | Sensitivity (%) | Specificity (%) | ||
Superior | 1 | 40.00 | 20.00 | 90.00 | 10.00 |
2 | 14.29 | 21.74 | 28.57 | 21.74 | |
3 | 0.00 | 47.83 | 14.29 | 30.43 | |
4 | 80.00 | 32.00 | 80.00 | 40.00 | |
5 | 11.11 | 90.48 | 0.00 | 95.23 | |
6 | 66.67 | 88.89 | 66.67 | 88.89 | |
7 | 50.00 | 78.57 | 50.00 | 78.57 | |
8 | 100.00 | 75.86 | 100.00 | 75.86 | |
Inferior | 1’ | 80.00 | 0.00 | 80.00 | 0.00 |
2’ | 75.00 | 50.00 | 75.00 | 61.54 | |
3’ | 80.00 | 60.00 | 80.00 | 64.00 | |
4’ | 80.00 | 52.00 | 60.00 | 88.00 | |
5’ | 57.14 | 82.61 | 28.57 | 100.00 | |
6’ | 66.67 | 70.83 | 66.67 | 75.00 | |
7’ | 0.00 | 71.43 | 0.00 | 82.14 | |
8’ | 33.33 | 62.96 | 33.33 | 70.37 |