直到有人连接点之前，可能只是时间问题。

prions - 感染性蛋白质 - 在病毒疾病的受害者眼中出现了。

Infected donor corneas had transmitted prion disease to recipients on at least a few occasions.

通常，后来被感染的病毒感染的患者在意识到被感染之前寻求医疗护理和测试。

如果 … ？

这种可能性令人恐惧。但是它需要调查。

私人are proteins, and, as every biology student knows,蛋白质取决于其存在的DNA和RNA。Yet prions have stumbled upon a way to be自我复制尽管如此。他们的病态形状会诱导类似序列但健康形状的蛋白质 - 在所有神经组织中大量发现 - 在与p虫相撞时会折叠。现在它们也具有传染性，这是无情和致命的多米诺骨牌效应的一部分。

他们引起的疾病是严峻的。Mad Cow Disease是最著名的，但是kuru由于其非正统的传输方式，还具有一定的声名狼藉。尽管罕见，但病毒疾病是无法治愈的，并迅速导致痴呆症死亡。如果是自发的Creutzfeldt-Jakob Disease（SCJD），最常见的prion病，一半的患者在症状发作后六个月内死亡。That figure reaches 95% within a year. In a particularly vexing twist, prions are also nearly impervious to destruction,even when attacked using a strenuous combination of disinfectants, heat, andpressure。

您可以想象，这使prions难以从受感染的组织和设备中消除。除了角膜移植外，SCJD还通过称为脑组织的移植来传播硬脑膜母校, growth hormone from cadavers, and perhaps most worryingly, neurosurgical instruments. So any method that might throw prions into the path of uninfected people deserves scrutiny.

输入研究published in November in the journalmBioby a team of American scientists这发现人类prion受害者的眼睛甚至在他们开始表现出症状之前就充满了传染性颗粒。此外，这些颗粒存在于它们的角膜表面，即眼睛的覆盖。11名SCJD受害者的眼睛中，有100％的眼睛捐赠了尸体进行研究。他们的角膜中有100％含有“低到中等”程度的prion播。由于角膜被振奋，因此捕食神经元中发现的蛋白质的prions可能通过这些微小的神经导管到达表面。

The retina – the light sensing layer at the back of the eye -- was most densely packed with prions in theinner and outer plexiform层。它们在组织污渍中很容易看到。

Normal retina (left) and diseased retina (right). Prions visible as a brownish stain in the inner and outer plexiform layers. Credit:Orrù et al. 2018

在11例病例中，一半是视网膜中的prions素浓度接近大脑中的水平，即prion活性的中心。

On the plus side, this finding, combined with the relative ease of assessing the retina, suggests a new target for traditionally tricky CJD diagnosis by non-invasive methods as电子图。

On the other hand, all remaining implications are disturbing. It’s unknown how early in the disease process prions appear in the eyes of humans, but in rodents, they are present prior to the onset of disease. About 40% of sCJD patients develop eye-related symptoms serious enough to warrant a consultation with an ophthalmologist. Somwhere between a quarter and a half go blind.

未诊断的CJD患者可能会寻求测试。作者写道，用于测试它们的诊断设备可能会受到污染。他们建议单使用仪器或采用新的净化程序，以对王室有效性更好。

同时，角膜移植在全球越来越受欢迎。根据作者的说法，2012年在116个国家 /地区进行了185,576次，新高。美国领导着人均世界，每年有64,000人进行。作者进一步建议超越并完善合成角膜的发展，以减少供体角膜的需求。

But there are yet more worrying implications of these findings.

As I wrote about at this blog earlier this year, there is a growing uneasiness that the clumping proteins associated with some of the most common and deadly neurodegenerative diseasesbehave in ways that are uncomfortably similar to prions.

One question suggested by this research is whether the eyes of Alzheimer’s and Parkinson’s patients are likewise filled with amyloid-beta, alpha-synuclein, and tau, and if that is the case, if the accumulation of those proteins in eyes might be exploited to aid diagnosis, a notoriously tricky proposition for these diseases.

Another is – and I am entering deep speculative territory here, as in, no one actually qualified to render an opinion on this has said it, I’m just putting two and two together in my head -- whether ophthalmological equipment could act as a vector for those diseases,as surgical equipment has already been hypothesized to do。

Don’t skip your eye exam. But given the seriousness of the stakes, I hope thatsomeone正在研究这些假设。是的，几率很低。但是赌注非常非常高。

Reference

Orrù, Christina D., Katrin Soldau, Christian Cordano, Jorge Llibre-Guerra, Ari J. Green, Henry Sanchez, Bradley R. Groveman et al. "prion种子分布在零星的克鲁特兹菲尔德 - jakob疾病患者的眼中。“mBio9, no. 6 (2018): e02095-18.