Visual Field Defects in Young Patients with Open-angle Glaucoma: Comparison between High-tension and Normal-tension Glaucoma

Purpose: To investigate the clinical features of young Korean patients with open-angle glaucoma (OAG), and to compare visual field (VF) defects between patients with normal-tension glaucoma (NTG) and those with high-tension glaucoma (HTG). Materials and Methods: Patients with OAG younger than 40 years of age were divided into NTG and HTG groups based on untreated intraocular pressure (IOP) level. The patients were matched according to the mean deviation of standard automated perimetry. VFs were divided into 2 pairs of corresponding areas across the horizontal meridian, and the depths of VF defects were compared. Tilt ratio and torsion degree of their optic discs were also compared between the 2 groups. Results: Thirty-four pairs of NTG and HTG eyes were matched. Although untreated IOP showed intergroup differences, there was no difference in age, refractive error, tilt ratio, torsion degree, and depth of VF defects between the 2 groups. However, NTG eyes showed deeper VF defects in the superior paracentral area than in the inferior paracentral area (-8.29±9.33 vs. -4.45±6.03 dB, P=0.038), whereas the HTG eyes showed symmetric VF defects. Moreover, the superior paracentral area showed deeper VF defects compared with the superior arcuate area in the NTG group (P=0.002). Conclusions: Young patients with NTG showed asymmetric VF defects in the paracentral area, whereas those with HTG did not show such asymmetric defects. This suggests that the level of IOP may affect the pattern of VF defects in young patients with OAG. However, these findings may not be generalizable to other populations.