Jain Sachin, Aref Ahmad A
Illinois Eye and Ear Infirmary, Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago College of Medicine, Chicago, IL, USA.
J Ophthalmic Vis Res. 2015 Apr-Jun;10(2):178-83. doi: 10.4103/2008-322X.163766.
Dementia and glaucoma are both neurodegenerative conditions characterized by neuronal loss leading to cognitive and visual dysfunction, respectively. A variety of evidence exists linking the two diseases including structural signs, specifically degenerative changes within ganglion cells. Both diseases become more prevalent with increased age, but that alone is unlikely to account for the increased co-prevalence of the diseases found in various studies. Neurotoxic substances including abnormal hyperphosphorylated tau and amyloid-β have been found in both disease processes suggesting possible pathophysiologic links between the diseases. The exact mechanism of apoptosis, whether by direct toxicity or potentiation, still needs to be established, but could prove important for both diseases. Another potential link relates to low intracranial pressure in patients with both diseases causing a high translaminar pressure gradient and optic nerve damage in certain patients. While this alone may not account for direct optic nerve damage, it could lead to cerebrospinal fluid (CSF) circulatory failure causing increased neurotoxins along the optic nerves with resultant damage. All of this evidence suggests the need to further study links between the two diseases, as this could prove instrumental in understanding their overlapping pathophysiology and developing directed therapies for both diseases. While this is more thoroughly investigated, it may be prudent to have a lower threshold for a glaucoma work-up in patients with pre-existing dementia.
痴呆症和青光眼均为神经退行性疾病，其特征分别为神经元丧失导致认知功能障碍和视觉功能障碍。有多种证据表明这两种疾病存在关联，包括结构体征，特别是神经节细胞内的退行性变化。两种疾病的患病率均随年龄增长而升高，但仅此一点不太可能解释各项研究中发现的这两种疾病共病率增加的现象。在这两种疾病的发病过程中均发现了包括异常过度磷酸化tau蛋白和β淀粉样蛋白在内的神经毒性物质，这表明两种疾病之间可能存在病理生理联系。凋亡的确切机制，无论是直接毒性还是增强作用，仍有待确定，但可能对这两种疾病都很重要。另一个潜在联系与这两种疾病患者的颅内压降低有关，这会导致某些患者出现高跨筛板压力梯度和视神经损伤。虽然仅此一点可能无法解释直接的视神经损伤，但它可能导致脑脊液（CSF）循环衰竭，使沿视神经的神经毒素增加，从而造成损伤。所有这些证据都表明有必要进一步研究这两种疾病之间的联系，因为这可能有助于理解它们重叠的病理生理学，并为这两种疾病开发针对性的治疗方法。在对此进行更深入研究的同时，对于已有痴呆症的患者，对青光眼进行检查的阈值可能较低，这或许是谨慎之举。
