Visual field damage proximal to fixation in normal- and high-tension glaucoma eyes

To compare in more detail the central visual field damage in normal-tension glaucoma (NTG) and high-tension glaucoma (HTG) eyes, a pointwise inner-group comparison of the data obtained with the Humphrey 10-2 was carried out in 68 NTG cases with maximum intraocular pressure (IOP) of < or = 21 mmHg and 62 HTG cases with maximum IOP of > or = 25 mmHg. All eyes had the usual field defects, with a mean deviation of > or = -15 dB (MD, STATPAC). Age, refraction and MD were matched between the two groups. Total deviation (TD, STATPAC), the difference between the measured threshold and the age-corrected normal reference at each test point of the 10-2 program, was used for pointwise inter-group comparisons. The data were analyzed with Wilcoxon rank-sum test and logistic discriminant analysis. The latter method was also applied to the data of the 30-2 program to confirm the results obtained with the 10-2 program. The comparisons using the different methods and programs gave consistent results. For a given amount of overall visual field damage in the two types of glaucoma, a superior arcuate area extending down to the horizontal meridian just nasal to the fixation point was significantly more depressed and an area inferior to the horizontal meridian and inferior temporal to the fixation point significantly less depressed in NTG eyes. HTG eyes were significantly more diffusely damaged in the central 10-degree visual field. NTG and HTG may have unique patterns of central visual field damage. These differences may implications in following NTG patients and studying the pathogenesis of this glaucoma.