Study, Superior and Inferior Visual Field Asymmetry patterns
The purpose of this study was to compare the patterns of visual field (VF) defects according to glaucoma severity in normal-tension and high-tension glaucoma (NTG and HTG).

A total of 1458 eyes with NTG (936) and HTG (522) were classified by mean deviation values into mild, moderate, and severe. The mean total deviation (mTD) values for each nasal, central, paracentral, arcuate 1, and arcuate 2 region of the Glaucoma Hemifield Test (GHT) were calculated. The differences in mTD between the superior and inferior hemifields of NTG and HTG were compared, and the degree of hemifield asymmetry was plotted.

--In NTG and HTG, the mTDs of the 5 regions of the superior GHT were significantly worse than those of the corresponding regions of the inferior GHT at all severity levels except for mild HTG.

--However, NTG showed significantly greater asymmetry than HTG in 2 regions at mild, 3 at moderate, and all 5 at severe.

--Moderate and severe NTG showed severe asymmetry with localized superior field defects concentrated at the central and paracentral areas with more than 8?dB asymmetry. However, in all HTG groups showed mild asymmetry with diffuse defects.

Finally, in NTG and HTG, the superior hemifield was more severely impacted than the inferior hemifield. The asymmetry in both groups grew as the severity of glaucoma rose, with NTG displaying more extensive asymmetric VF deficits in the central and paracentral areas, whereas HTG did not.