低压性青光眼和原发性开角型青光眼视乳头形态的比较

Comparison between the optic nerve heads in low tension glaucoma and primary open angle glaucoma

The optic nerve heads of 52 eyes of 42 patients with low tension glaucoma (LTG) were compared with those of 67 eyes of 47 patients with primary open angle glaucoma (POAG). The mean of the highest intraocular pressure was 2.43 +/- 0.03 kPa (18.3 +/- 0.2 mmHg) in the LTG group, and 3.90 +/- 0.09 kPa (29.3 +/- 0.7 mmHg) in the POAG group, the difference being significant (P less than 0.001). The visual field loss was similar in the two groups, only the temporal optic disc rim in LTG was narrower than in POAG, the rim to disc ratios in other meridians and the cup to disc ratios were not significantly different between the two groups. Deep cups, striate openings on the lamina cribrosa and blood vessel overpasses were significantly more seen in POAG than in LTG Hemorrhages on the disc were more frequent in LTG than in POAG. All these findings may serve as complementary indicators in differential diagnosis between these two types of glaucoma, and support the belief that different mechanisms exist for optic nerve damage in glaucoma.