Retinal Nerve Fiber Layer Damage as Assessed by Optical Coherence Tomography in Eyes with a Visual Field Defect Detected by Frequency Doubling Technology Perimetry but Not by Standard Automated Perimetry

When SAP is within normal range, some patients with VF loss detected by FDT show a decreased RNFL thickness, possibly indicating the presence of glaucomatous damage. These results support the validity of FDT as a tool to detect early glaucoma.