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 glaucomatous abnormality of visual field sensitivity. A normal value for retinal thickness was determined and then compared in corresponding local sectors.
MethodsThirty 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.
ResultsThe 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%.
ConclusionsIn 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.