Objective: To investigate the distribution of diffuse and local retinal-nerve-fiber-layer defects (RNFLD) and their clinical features in early primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG).
Method: The types of RNFLD in 81 cases with POAG and 70 cases with NTG were observed, the distribution of diffuse and local RNFLD were analyzed, and the maximum untreated intraocular pressure (IOP) and the history of optic disc hemorrhage between the two types of RNFLD in the two glaucomatous groups were compared.
Results: RNFLD appeared in 78 of 81 cases with POAG, 50 of them were diffuse and 28 were local; 27 of diffuse and 43 of local RNFLD were found in 70 cases with NTG. The IOP was (28.78 +/- 5.41) mm Hg in the diffuse and (26.2 +/- 5.2) mm Hg in the local type in POAG (t = 2.04, P < 0.05), and (19.2 +/- 1.9) mm Hg and (17.8 +/- 2.0) mm Hg, respectively in NTG (t = 2.94, P < 0.05). The incidence of disc hemorrhage was 10/78 and 18/70 in POAG and NTG, respectively (chi(2) = 4, P < 0.05). That was 3/50 in the diffuse and 7/28 in the local type in POAG (chi(2) = 4.22, P < 0.05), and 3/27 and 15/43, in NTG respectively (chi(2) = 4.91, P < 0.05). There were no statistic differences in the diffuse type between the POAG and NTG groups (chi(2) = 0.15, P > 0.05), and neither were in the local type (chi(2) = 1.31, P > 0.05).
Conclusion: The diffuse RNFLD tends to be distributed in POAG, while the local RNFLD tends to be distributed in NTG. The maximum IOP in the eye with diffuse RNFTD is higher than that in the eye with local RNFLD, either in POAG or NTG group. The occurrence of disc hemorrhage is higher in the eye with local RNFLD than that in the eye with diffuse RNFLD in the two groups respectively. There are differences in clinical features between the two types of RNFLD in early POAG and NTG.