Abstract
Purpose: :
to evaluate the correspondence between function-selective visual field (VF) testing and the macular ganglion cell layer (GCL) thickness.
Methods: :
Subjects were 29 glaucomatous eyes (14 with preperimetric and 15 with early-stage glaucoma) and 20 normal eyes (52.9 ± 17.5 years). Besides Standard Automated Perimetry (SAP) using the Humphrey Field Analyzer, function-selective VF testing including Short Wavelength Automated Perimetry (SWAP), flicker perimetry on the Octopus 311, Frequency Doubling Technology (FDT) on the Humphrey Matrix and Heidelberg Edge Perimeter(HEP) were performed. Structurally, the GCL (superior and inferior) and inner plexiform layer (IPL)thickness was measured by Fourier Domain Optical Coherence Tomography (FD-OCT) with a macular 6 mmx6mm cube scan (Topcon, Inc). The areas under the receiver operating characteristic curves (AUCs) for the VF testing were calculated for glaucoma detection using the number of abnormal points in 16 test points (8 each in the superior and inferior VFs) in the range of the macular cube scan. Correspondence between abnormal points (%) and GCL+IPL thickness was evaluated for the superior and inferior VFs separately. Abnormality was defined as a point with sensitivity ≤ the normal 5% probability level in total deviation in VF and the GCL+IPL thickness with a half VF corresponding to sensitivity <the normal 5% probability level in FD-OCT for an age-similar group.
Results: :
The AUCs of the total deviation for SWAP, Flicker, FDT and HEP were 0.78, 0.74, 0.77 and 0.74, respectively. With abnormal GCL+IPL thickness, the respective percentages of abnormality were 62.5%, 35.7%, 41.7% and 72.5% (superior), and 60.0%, 33.8%, 50.0% and 77.5% (inferior). With normal GCL+IPL thickness, the respective percentages were 36.6%, 6.3%, 17.0% and 54.5% (superior) and 34.9%, 9.9%, 19.7% and 48.0% (inferior) for the glaucomatous eyes; and 8.1%, 2.5%, 9.4% and 31.3% (superior) and 14.4%, 3.1%, 11.3% and 34.4% (inferior) for the normal eyes.
Conclusions: :
With abnormal GCL thickness, the function-selective VF testing could detect the corresponding abnormality. However, SWAP and HEP indicated abnormality in total deviation even in the normal and glaucomatous eyes with normal GCC thickness. This suggested that abnormality in VF should be more carefully defined.
Keywords: visual fields • ganglion cells