Applicability of automatic spectral domain optical coherence tomography for glaucoma mass screening

Purpose: To perform a preliminary evaluation of the applicability of automatic spectral domain optical coherence tomography (ASD-OCT) for glaucoma mass screening in a population-based setting.

Methods: Information using ASD-OCT (thicknesses of the macular retinal nerve fiber layer [mRNFL], disc retinal nerve fiber layer [dRNFL], ganglion cell layer [GCL] + inner plexiform layer [IPL]; GCL+, and ganglion cell complex [GCL + IPL + RNFL; GCL++]) was obtained from 245 eyes of 123 glaucomatous subjects and 1,454 eyes of 727 normal subjects. For all four measurements, each grid was scored as follows: 2= within 95% of the normal database; 1= within 5%; and 0= within 1%. The sums of each grid (mRNFLs, dRNFLs, GCL+s, and GCL++s) were used as indicators. The effectiveness was estimated by the area under the receiver operating characteristic curve (AUC-ROC). The appropriate algorithm was then applied to 10,145 eyes of 5,088 subjects from the general population (mean age: 50.1±10.3 years).

Results: AUC-ROC of mRNFLs, dRNFLs, GCL+s, and GCL++s was 0.927 (95% confidence interval [CI] =0.903-0.950), 0.919 (95% CI =0.899-0.940), 0.972 (95% CI =0.958-0.986), and 0.972 (95% CI =0.957-0.986), respectively. The discriminant analysis demonstrated that the canonical correlation coefficients of mRNFLs, dRNFLs, GCL+s, and dGCL++s were 0.07, 0.255, 0.661, and 0.207, respectively. AUC-ROC of the discriminant value was 0.971 (95% CI =0.956-0.986). The sensitivity/specificity using GCL+s (cutoff =160) was 81.6%/99.9%. This algorithm was applied to the general population, and 1,658 eyes (16.3%) were found to be positive for glaucoma.

Conclusion: In the case-control setting, ASD-OCT showed a relatively high performance, and the thickness of the GCL + IPL was the best predictor. However, further prospective studies are needed, in which the results of this study are compared to the general population, because the false-positive rate of glaucoma seems to be high.