| Affiliation |
(AGL) Chairman, Department of Ophthalmology, The Methodist Hospital, Houston, Texas; Professor of Ophthalmology, Weill Cornell Medicine, New York City, New York; (SD) Baylor College of Medicine, Houston, Texas |
| Transcript |
So today I want to talk to you about how autoimmune related retinopathies and autoimmune optic neuropathies can come to neuro-ophthalmology. So, when we have an autoimmune retinopathy, usually your own body is attacking yourself and that can be for no reason and that is an autoimmune related retinopathy and optic neuropathy. ARRON we call it. Or it can be paraneoplastic optic neuropathy or paraneoplastic retinopathy with or without optic neuropathy. And these are cancer associated retinopathy (CAR) or melanoma associated retinopathy (MAR) or paraneoplasticoptic neuropathy. So, whenever we're dealing with these autoimmune retinopathies, it has a very particular sound to it. The symptoms are usually day blindness, which is hemeralopia, or night blindness, which is nyctalopia. So, the rods and the cones care whether it's day or night, but the optic nerve really doesn't care whether it's day or night. So, if they're night blind or day blind, we really should be thinking about retinopathy. The fundus exam is usually normal. They have variable acuity. They usually have a peripheral field constriction and then over time the acuity will go out. In the beginning the fundus is normal. In all three of these conditions, the paraneoplastic CAR, MAR, or paraneoplasticoptic neuropathy, or ARRON. The fundus looks normal. Over time arteriolar narrowing and then the development of optic atrophy but it's a very very late sign. And so we really need to produce evidence for the retinopathy not based on the fundus exam or OCT which are normal, but by using electrophysiology; and that's going to bean ERG, either a multifocal ERG if it's a focal problem or a full field ERG if it's a diffuse problem. And so in the CAR, they're going to have markedly reduced amplitudes so it might even be a flat ERG where both the A wave and the B wave are decreased. But in MAR, there's going to be no B wave, just A wave, so it's an electronegative ERG. And in paraneoplastic optic neuropathy, the ERG will be normal. When an ARRON ,you might have a decreased amplitude of A wave, B wave, or both in ARRON. The way to make the diagnosis after the electrophysiology is we have laboratory tests for the antibodies. So we can do the autoimmune antibodies. And for the CAR, the most common cancer associated with CAR is small cell carcinoma of the lung. But they're going to have a full body search for cancer-mammogram, general physical exam, chest/abdomen/pelvis imaging, CT usually followed by PET scan. If it's MAR, these people know they have melanoma; in CAR they don't know they have cancer. The paraneoplastic optic neuropathy people also don't know they have cancer. So these people including ARRON, need to have a paraneoplastic workup looking for a remote lesion. And the antibody that we're looking for that's most commonly tied to the cancer is the 23 kilodalton recovery. However, there are other ones crimp 5and a whole bunch of other ones. The treatment once we get the antibody identified if the ERG is abnormal if they're progressing, steroids, IVIG, antibody against that antibody, or plasma exchange but usually nothing works. The main thing is get rid of the cancer. So you need to know a little bit about autoimmune retinopathy with or without optic neuropathy. ARRON is a key autoimmune related retinopathy and optic neuropathy, and the paraneoplastic forms CAR (cancer associated retinopathy) or MAR(melanoma associated retinopathy)or just paraneoplastic optic neuropathy. Check the antibodies, do the electrophysiology, and treat the antibodies, IVIG plasma exchange |
