Gottanka Johannes, Kuhlmann Alexander, Scholz Michael, Johnson Douglas H, Lütjen-Drecoll Elke
Department of Anatomy II, University of Erlangen-Nürnberg, Germany.
Invest Ophthalmol Vis Sci. 2005 Nov;46(11):4170-81. doi: 10.1167/iovs.05-0289.
To determine whether differences in the optic nerve occur in eyes with primary versus secondary open-angle glaucoma.
Optic nerves obtained at autopsy from 36 eyes with primary open-angle glaucoma (POAG) and 15 with pseudoexfoliation glaucoma (PEXG) were studied quantitatively and qualitatively. Axon counts, fibrosis, capillary number and density, and arteriosclerotic changes were assessed in the postlaminar optic nerve and compared to normal age-matched autopsy eyes. Changes in composition of extracellular matrix components were evaluated by immunohistochemistry and electron microscopy.
Marked differences were found between POAG and PEXG. Axon loss in eyes with POAG but not in PEXG was associated with increasing connective tissue in the septa and surrounding the central retinal vessels, including increased amounts of type IV and VI collagen. The total number of capillaries decreased with the loss of axons in both POAG and PEXG. POAG nerves, however, had a decrease in the density of capillaries, whereas in PEXG the capillary density did not change with axon loss. Arteriosclerotic changes were more common in glaucomatous eyes than in age-matched control eyes.
The difference in morphology of the optic nerves between POAG and PEXG indicates that in eyes with POAG, elevated IOP cannot be the only pathogenetic factor in glaucomatous optic neuropathy. Additional factors, inducing fibrosis and loss of capillaries, seem to be involved. Such additional factors may also contribute to the clinical finding in POAG that nerves can become damaged without elevation of intraocular pressure.
确定原发性与继发性开角型青光眼患者的视神经是否存在差异。
对36只原发性开角型青光眼（POAG）和15只剥脱性青光眼（PEXG）患者尸检时获取的视神经进行定量和定性研究。评估视盘后段视神经的轴突计数、纤维化、毛细血管数量和密度以及动脉硬化变化，并与年龄匹配的正常尸检眼进行比较。通过免疫组织化学和电子显微镜评估细胞外基质成分的组成变化。
POAG和PEXG之间存在显著差异。POAG患者的视神经存在轴突丢失，而PEXG患者则无，这与中隔和视网膜中央血管周围结缔组织增加有关，包括IV型和VI型胶原蛋白含量增加。POAG和PEXG患者的毛细血管总数均随轴突丢失而减少。然而，POAG患者的视神经毛细血管密度降低，而PEXG患者的毛细血管密度并未随轴突丢失而改变。青光眼患者的动脉硬化变化比年龄匹配的对照眼更常见。
POAG和PEXG视神经形态的差异表明，在POAG患者中，眼压升高并非青光眼性视神经病变的唯一致病因素。似乎还涉及诱导纤维化和毛细血管丢失的其他因素。这些额外因素也可能导致POAG患者出现眼压未升高但神经却受损的临床现象。
