| Affiliation |
(AGL) Chairman, Department of Ophthalmology, The Methodist Hospital, Houston, Texas; Professor of Ophthalmology, Weill Cornell Medicine, New York City, New York |
| Transcript |
"I want to just tell you a little bit about how thyroid eye disease is a mimic in ophthalmology. And what I mean by that is it can end up in the other sub-specialties within ophthalmology and if someone has seen every sub-specialist in your practice (if it's a multi-specialty group ophthalmology practice) you really should be thinking that thyroid eye disease might be a single unifying diagnosis. The reason is from the front to the back, including the orbit, thyroid eye disease can cause inflammation that can present to you in your subspecialty area. So, if your area is cornea and anterior segment, the thyroid eye disease patient might say, "I have a red eye" and that redness is usually over the insertion of the horizontal recti. But if you have a very particular location: the caruncular inflammation. So if we see the caruncular inflammation, that is very bothersome that it's thyroid. And so you know the caruncle is right here medially. So if we see the inflammation there or over the horizontal recti that is the clue that this red eye might not be conjunctivitis or allergy and it might be thyroid eye disease. If you're in the strabismus unit and you're dealing with pediatric ophthalmology and strabismus, the thyroid eye disease can be in the extraocular muscles and produce diplopia and ophthalmoplegia. As you know, the involvement is inferior > medial > superior > lateral rectus. That is the order of the muscles that are involved. So it's like "I'm so lucky not to have thyroid" or some other mnemonic that you might have. It causes the big muscles so the extra ocular muscles are enlarged because the glycosaminoglycans, the fibroblasts, the differentiation, all of the immunology that we've covered in different videos is making these muscles big. That produces the symptoms of diplopia and the sign of ophthalmoplegia. Usually, a hypotropia and esotropia because it's a restricted pattern in the muscle. You might end up seeing your glaucoma doctor. And the reason is, if you have all this stuff in the orbit, the orbit is a closed box. And so if you put too much soft tissue into the orbit, the intraocular pressure will go up because the intraorbital pressure is going up. And that can look to you like open angle glaucoma because you do a gonio and the angle is open and you're going to think it's primary open angle glaucoma. But because primary open-end glaucoma doesn't cause strabismus or the red eye, that's the person you really should be thinking that maybe it's a secondary but open-angle glaucoma. And so patients like this might have difficult to treat intraocular pressure or they might have progression that's too rapid for glaucoma or involvement of the wrong fibers. So, as you know, in the optic nerve the fibers involved in glaucoma are the temporal fibers which are at the top and the bottom of the disc. So, it causes vertical cupping and notching, and it doesn't like to involve the nasal fibers which is the papillomacular bundle and the nasal fibers. So if we see temporal field defect or temporal power, you should be thinking maybe this glaucomatous cupping is from orbital disease thyroid eye disease. The person also obviously could end up seeing the orbit doctor because that same extracurricular muscle enlargement is also affecting the fat. So when we have big muscle and big fat you're going to get proptosis chemosis. These are the orbital signs. And you might have the lid signs: lid retraction and lid lag. These are going to come to the orbit doctor and the oculoplastic service. And, after all of this, you might end up with neuro-op. In neuro-op, they're going to be wondering, "Why is this person losing their vision? Why do they have such rapid glaucoma? Why do they have double vision?" And the dangerous part of this is they might come to neuro-op and they already had an MRI that which is negative because we didn't image the right area. A negative MR of the head. So, you can see how dangerous this thyroid eye disease can be as a mimic. So, if a patient has seen cornea, strabismus, glaucoma, orbit, oculoplastics, and neuro-op and has a negative MR on the head but has a red eye, coruncular inflammation, diplopia, ophthalmoplegia, a bad glaucoma, or a weird glaucoma, proptosis, lid findings, this is the time to be thinking that the thyroid eye disease is the mimic. If they've seen everybody in your clinic." |
