Purpose:
To compare the diagnostic ability of macular inner retinal and peripapillary retinal nerve fiber layer (RNFL) measurements by RTVue spectral domain optical coherence tomography (SDOCT) in early glaucoma.
Methods:
In a cross-sectional, observational study, 64 eyes of 64 normal subjects and 59 eyes of 41 early glaucoma patients underwent macular and RNFL imaging with RTVue. Normal subjects had normal and reliable standard automated perimetry (SAP) results and a normal ocular examination. Glaucomatous eyes had a repeatable abnormal SAP result that satisfied at least two of the Anderson’s criteria and the mean deviation was better than or equal to - 6 dB. The areas under the receiver operating characteristic curves (AUCs) and the sensitivities at a fixed specificity of 95%, of the macular and RNFL parameters were compared.
Results:
The AUCs for the macular inner retinal parameters ranged from 0.587 for the macular inner retinal superior minus inferior thickness average to 0.896 for the ganglion cell complex - focal loss volume (GCC-FLV). The AUCs for the RNFL parameters ranged from 0.520 for the temporal quadrant thickness to 0.784 for the inferior quadrant RNFL thickness. The AUC of the best macular parameter (GCC-FLV) was significantly greater (p=0.01) than the best RNFL parameter (inferior quadrant thickness, figure). Sensitivity at a fixed specificity of 95% was 57.8% for GCC-FLV and was 18.8% for the inferior quadrant RNFL thickness.
Conclusions:
Macular parameters with SDOCT have a better diagnostic accuracy to detect early glaucoma compared to the RNFL parameters.
Keywords: ganglion cells • imaging/image analysis: clinical • nerve fiber layer