Correlation between Retinal Nerve Fiber Layer Thickness and Visual Field in Normal Tension Glaucoma Patients

ABSTRACT

PURPOSE: To determine the correlation between retinal nerve fiber layer (RNFL) thickness and visual field defect for early detection of normal tension glaucoma (NTG). METHODS: Sixty eyes newly diagnosed with NTG and 50 normal eyes were analyzed by optical coherence tomography and a short wave length automated perimetry test. The relationship between RNFL, divided into 12 areas, and visual field, divided into 21 areas, were analyzed. RESULTS: Sixty eyes that revealed visual field defect by SWAP showed thinning of the RNFL. OCT sectors 6-o'clock, 7-o'clock, and 8-o'clock (inferior and inferotemporal) and SWAP visual field zones 13, 14, 15 and 16 (superior paracentral, arcuate areas, and the nasal step) were the most frequently damaged. The strongest associations were between the inferior and inferior temporal RNFL sectors 6, 7, and 8-o'clock and the superior nasal/arcuate visual field zones 13, 14, and 15 (R2 range=15.9-34.6%, all p<0.05). CONCLUSIONS: A combination of these two methods may be helpful for the early detection of NTG.