Insights on Ocular Management for Marfan Syndrome
4:53-8:48
What are the Marfan conditions, ocular conditions, so this is a cartoon basically showing the diagram of the schematic of the eye. This is only the front part and if you will and I don't know if you I hope you can see my cursor, so this, if you make a round circle this is the entire eyeball. This one gives you some view that how the, what the anatomy is. The light green or dark green. This is just the lens in a different condition. This is relaxed the condition. This is accommodation meaning that I can move my eye from the distance target to near very quickly without needing reading glasses. Those are the young eyes. The reason you can do this is because the shape of the lens can change pretty easily dictated by those fibers. Those fibers are called zonular fibers and those are almost like a ligament suspending the lens to the eye wall and specifically to the this muscle in the orange color. The muscle can relax, contract therefore and changes the shape, relaxation or contraction of the lens and in turn change this the, the shape of the lens.
こちらは、眼の前半分の図です。レンズ（水晶体）が薄いグリーンの状態と濃いグリーンの状態がありますが、薄いグリーンが安静時の状態、濃いグリーンが焦点を合わせている状態です。焦点を合わせている状態は、メガネを使わずに遠くの物から近くの物へと、急いで視点を切り替えた時の状態です。若い方であれば、このように焦点を合わせることができます。こうした切り替えが可能になるのは、糸のような組織によって、レンズの形を容易に変えることができるからです。この糸状の組織をチン小帯と呼びます。チン小帯はレンズを眼の壁（オレンジ色の筋組織）に吊り下げる靭帯のような働きをしています。筋組織が伸び縮みすることで、レンズの形が平坦になったり、丸みを帯びたりします。
So it's very intricate connection between the muscle, between the fiber, between the lens, so the fibers have to be really sturdy and has to be really flexible, has to function well and those fibers, zonular fibers they are mainly composed with fibrillin 1, which is encoded by FBN1. Now, you know, those Marfan patients you can get a mutation in FBN1 therefore the zonulars are not stable. If they're not stable the lens can get dislocated and that's called the ectopia lentis.
この様に、筋組織とチン小帯、レンズの間には非常に複雑な繋がりがありますので、チン小帯にが上手く機能するには、十分な強度や柔軟性が求められます。チン小帯は主にフィブリリン1で構成されており、このタンパク質をコードするのがFBN1遺伝子ですので、この遺伝子に変異があるマルファン症候群の患者さんでは、チン小帯が不安定になります。これによりレンズがずれた状態が水晶体偏位と呼ばれます。
So this is a schematic view. This is the the real picture of one of my patients. This is actually it's not a Marfan but I think is somewhat telling I want you to get the point. This is one eye. You can see the black hole that is when you dilated the pupil that you can, you don't see anything because the lens is clear and the lens, zonular fibers are behind the orange color which is, is depicting the iris, so you really don't see anything. It's lens is in the perfect position. This one the other eye. You can see those fiber covered with material this is caused by another connective tissue disease and showing those zonulars. They're just not stable. They are not functioning well, therefore the lens is dislocated, so it's a pretty easy to appreciate dislocated lens.
こちらの画像は私の患者さんのものです。マルファンではありませんが、ポイントは伝わると思います。片目の画像です。左側は瞳孔が開いている状態です。レンズが透き通っていて、チン小帯はオレンジの虹彩の後ろに隠れているので見えません。正常な眼の状態です。右側ですが、チン小帯が見えます。結合組織疾患に起因する何らかの物質に覆われています。チン小帯は不安定で、上手く機能していません。これが水晶体偏位です。容易にわかります。
That is another patient. This is a patient of mine with the true Marfan syndrome both eyes. This is one eye. You can see this the lens is clear here but there is a crescent shape right between the pupil margin and the lens and you can tell the lens is dislocated. It's dislocated superiorly move meaning the lens is moved upward. You don't even see those zonules unlike the previous slide. Previous patient zonules are still there just covered with a different material and it's not stable. Those zonules are gone, so that's why the lens is dislocated superiorly and this is are even more obvious and you can see that the lens actually bisecting the pupil. You can imagine the light will go through the light, lens will go through this the portion that without focusing lens and you're really confused when the images form on the back part of the eye.
こちらのスライドの画像は、私が担当するマルファン患者さんの両目の画像です。上の画像では、レンズは綺麗ですが、矢印の部分に三日月形が見えますので、水晶体が上側にずれていることがわかります。チン小帯は見えません。先ほどの患者さんでは、何かに覆われた状態の不安定なチン小帯が見えましたが、こちらの画像では消失していますので、水晶体が上にずれたということです。下の画像では、レンズが瞳孔を二分していますので、よりはっきりとわかります。目から入った光は、こちらのレンズがない部分とレンズがある部分を両方を通過しますので、眼の後ろで像が結ばれた際には、患者さんは戸惑うことになります。
The Marfan Foundation did not participate in the translation of these materials and does not in any way endorse them. If you are interested in this topic, please refer to our website, Marfan.org, for materials approved by our Professional Advisory Board.
The Marfan Foundation は、当翻訳には関与しておらず、翻訳内容に関してはいかなる承認も行っておりません。このトピックに興味をお持ちの方は、Marfan.org にアクセスし、当協会の専門家から成る諮問委員会が承認した内容をご参照ください。
