FDT and SWAP detect functional losses in cases of suspected glaucoma before glaucomatous losses detected by SAP.

To determine and validate the diagnostic ability of a linear discriminant function (LDF) based on the retinal nerve fiber layer thickness at each of the 12 clockhour positions obtained using optical coherence tomography for discriminating between healthy eyes and eyes with early glaucomatous visual field loss. Methods: We prospectively selected 62 consecutive healthy individuals and 73 patients with open-angle glaucoma to calculate the LDF. Another independent prospective sample of 280 healthy eyes and 302 glaucomatous eyes was used to evaluate the diagnostic accuracy of the LDF. Results: The proposed function was LDF=15.584-(12o'clock segment thickness ϫ 0.032)-(7-o'clock segment thicknessϫ 0.041)-(3-o'clock segment thickness [nasal side] ϫ 0.121). The greatest area under the receiver operating characteristic curve was observed for our LDF in both populations: 0.962 and 0.922. Our LDF and the average thickness yielded sensitivities of 74.5% and 67.8%, respectively, at a fixed specificity of 95%. Conclusions: The LDF increased the diagnostic ability of the isolated retinal nerve fiber layer thickness at the 12 clock-hour positions. Compared with optical coherence tomography-provided parameters, our LDF had the highest sensitivities at 85% and 95% fixed specificities to discriminate between healthy and early glaucomatous eyes.

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Objective To evaluate and compare the diagnostic accuracy of the Heidelberg retina tomograph (HRT) version 3 with that of glaucoma specialists using stereophotography in discriminating between normal eyes and patients with early glaucomatous visual field loss. Methods A total of 105 eyes of 105 individuals were prospectively and consecutively recruited. The sample comprised 51 normal and 54 early glaucomatous eyes, as defined by intraocular pressure and standard automated perimetry results, regardless of optic disc appearance. Receiver operating characteristic (ROC) curves were plotted for the HRT3 parameters and a linear discriminant function (LDF) developed in our hospital. Best sensitivity-specificity pairs were compared between the HRT3 parameters, with the highest areas under the ROC curve (AUCs) and evaluation of optic disc stereophotographs. Agreement between methods for measuring vertical cup-to-disc ratio was evaluated with the Bland-Altman plot. Results The average visual field mean deviation was -2.90 dB. The HRT3 parameters with the largest AUCs were our LDF (0.900), rim volume (0.883), and vertical cup/disk ratio (0.880), with no significant differences between these parameters. Sensitivity-specificity pairs were 79.6-100% (clinical evaluation), 83.3-86.3% (our LDF), 64.8-96.1% (final glaucoma probability score), and 68.5-90.2% (global Moorfields regression analysis). ConclusionsThe diagnostic accuracy for differentiating normal eyes from those with early visual field defects was similar between clinical evaluation of the optic disc and evaluation with the HRT3. The use of our LDF increased the sensitivity-specificity balance with respect to the HRT-provided parameters. The diagnostic accuracy of the HRT classifications was comparable to that of an experienced glaucoma specialist.

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