Dandona L, Quigley H A, Brown A E, Enger C
Glaucoma Service, Wilmer Ophthalmological Institute, Johns Hopkins University, School of Medicine, Baltimore, Md.
Arch Ophthalmol. 1990 Mar;108(3):393-8. doi: 10.1001/archopht.1990.01070050091039.
We digitized magnified photographs of cross-sections of the laminae cribrosae of 16 normal subjects 50 or more years of age. The sample included 7 blacks and 9 age-matched whites. Connective tissue area as a proportion of the lamina cribrosa area was significantly less and pores were significantly larger in the superior and inferior than in the nasal and temporal quadrants of the lamina cribrosa. These differences were more pronounced for peripheral as compared with central regions of the lamina cribrosa. Less connective tissue support for nerve fibers in the superior and inferior quadrants of the optic nerve head could contribute to their greater susceptibility to glaucoma damage by allowing greater distortion of these regions at elevated intraocular pressures. The least connective tissue support was present in the inferoperipheral region of the lamina cribrosa, which may be related to the greater frequency of superior visual field defects in glaucoma. Blacks had larger total lamina cribrosa area, indicating a larger optic nerve head, and also a greater number of laminar pores than whites. However, the connective tissue proportion and pore size distribution in the laminae cribrosae of blacks were almost identical to those of whites. We found no evidence suggesting that the greater susceptibility of blacks to glaucoma damage is due to less connective tissue support for nerve fibers passing through their laminae cribrosae than in whites.
我们将16名50岁及以上正常受试者的筛板横断面放大照片进行了数字化处理。样本包括7名黑人及9名年龄匹配的白人。筛板上、下象限的结缔组织面积占筛板面积的比例显著小于鼻侧和颞侧象限，且孔隙显著更大。与筛板中央区域相比，这些差异在周边区域更为明显。视神经乳头上下象限对神经纤维的结缔组织支持较少，在眼内压升高时，这些区域更容易发生更大程度的变形，从而可能导致它们对青光眼损害的易感性更高。筛板的下周边区域结缔组织支持最少，这可能与青光眼患者上半视野缺损发生率较高有关。黑人的筛板总面积更大，表明视神经乳头更大，且筛板孔隙数量也比白人更多。然而，黑人筛板中的结缔组织比例和孔隙大小分布与白人几乎相同。我们没有发现证据表明黑人对青光眼损害的易感性更高是因为穿过其筛板的神经纤维所获得的结缔组织支持比白人少。
