Characteristics of Normal-tension Glaucoma Patients with Temporal Retinal Nerve Fibre Defects

Glaucomatous visual field (VF) damage usually involves in the Bjerrum area, which refers to outside the central 10 degrees region. However, some reports suggest that structural damage to the macula occurs even in the early stages of glaucoma. We investigated the characteristics of normal tension glaucoma (NTG) patients with temporal retinal nerve fibre layer (RNFL) defects. Ninety eyes from 90 subjects including 30 normal eyes, 30 eyes of 30 patients with normal-tension glaucoma with temporal RNFL defects, and 30 eyes of 30 patients with normal-tension glaucoma with inferotemporal or superotemporal RNFL defects were enrolled. The best-corrected visual acuity (BCVA) decreased significantly in glaucomatous eyes with temporal RNFL defects as compared with in controls and glaucomatous eyes with inferotemporal or superotemporal RNFL defects. VF tests showed more frequent central or cecocentral VF defects involving the central 10 degrees region in glaucomatous eyes with temporal RNFL defects. VF defects were more frequently detected on short-wavelength automated perimetry (SWAP). Eyes with temporal RNFL defects had generally reduced ganglion cell-inner plexiform layer (GCIPL) thickness. In addition, the BCVA, GCIPL thicknesses, and SWAP findings were significantly different in glaucoma patients with temporal RNFL defects according to their colour vision deficiency, not RNFL thickness or standard automated perimetry (SAP) results.