Christopher Hood, MD, Assistant Clinical Professor in Ophthalmology at the Kellogg Eye Center, talks about corneal transplants to remove vison-impairing scar tissue from the eye after shingles and other like-infections.
I want to start by asking you a little bit about shingles complications and what that can do to a person’s eye. Would you be able to tell our viewers a little bit about it?
Dr. Hood: Shingles, unfortunately, is very common, especially as the population gets older. It’s more common in older patients, but we are seeing it in younger and younger patients. Shingles is basically the chickenpox virus that lives in one of the nerves in our body and can actually travel through a nerve and re-activate. So, people can get it, commonly, in the nerves around the trunk, but it can also come around the eye and the nerve that serves the eye. And so, it sort of reactivates in some people, we don’t quite know why it comes out like that, but when it comes out, it can come out, quite commonly, around the eye. It can have long term effects for people around their eye.
Do people have symptoms? Will they know that this is happening? And is there anything they can do before it gets to that very serious situation?
Dr. Hood: People will almost always have symptoms at some point. In fact, it usually is a quite painful process to have. Oftentimes, the first symptom, is really just some tingling of the skin. But usually, shortly thereafter, you’ll get some vesicles or little bumps on the skin. I specialize around the eye and some people will get that along the scalp, this kind of distribution of the nerve, the virus sort of coming out in the skin. Usually, it’s at that point that people seek care from their general practitioner, or even an E.R. because it’s so painful for many patients.
Do we know what causes those outbreaks? Is it caused by stress or…?
Dr. Hood: There may be different precipitators, we don’t know exactly what it is. We think that there’s maybe boosting immunity when people are actually exposed to the chickenpox virus and since people don’t get the chickenpox virus anymore, we think there’s a waning immunity in people. People that had chickenpox initially when they were young, or even had the vaccine, and now they’re getting it again because it’s coming out in their body because this is a living virus that actually lives in our body. If we suppress it, it’s of no major concern, it’s only if it comes out activated again. So, we think a weakened immune system in any way could cause that, but we also see it in a lot of people that have no known weakened immune system– young, healthy patients.
At what point does it get into the eye? Can you explain how it happens when the infection goes into the eye?
Dr. Hood: So, it can affect the nerve that is around the eye and then, at that point, it can affect the eyelid, and the virus, we think, could actually be on the cornea. Basically, by traveling down the nerve, the same nerve that serves the sensation to the eye is the nerve that serves this distribution of the skin. So, if it comes out that nerve, it can get into the eye by that mechanism. Now the problem with the eye is the virus itself can be treated. Most people are started if they come in soon enough, on antiviral medications, usually pills, for 10 to 14 days and that takes care of the active virus. With the cornea, specifically, it’s the long-term effects, typically starting a month or more after their active acute viral infection, where they can get problems. It’s actually, we think, mostly an inflammatory response, to a large degree, in the cornea.
What kind of things are they going to see? This is a month later… they may not even really be attuned to it. What are they going to start to feel…?
Dr. Hood: So, usually, the first thing that would be, in some way, blurred vision. They may have a little bit of redness of the eye or light sensitivity—basically, these signs of inflammation or the eye hurting or having pain in the eye. Those are oftentimes the first thing that people will see. In the best case, these people will be seeing an ophthalmologist when they have their initial outbreak of the shingles around the eye. Then a few weeks after that initial onset, we’ll check them and see if we’re seeing any signs of inflammation in the cornea.
Is there a treatment, right then, when they’re symptomatic?
Dr. Hood: There is. So, the ideal treatment at that point is usually going to be steroid eye drops to treat the inflammation in their cornea. If they had eye pressure that’s increased because of the inflammation, we’ll treat that as well. Sometimes we’ll put them on antiviral medications again. It’s not exactly clear if there’s a role for that, but that’s something we may consider. A lot of it is controlling the inflammation because the inflammation, over time, will cause scarring of the cornea if untreated or not treated adequately.
That was my next question. This is obviously a serious condition that people need treatment for. If it goes on, what happens? What happens to people’s eyes and eyesight?
Dr. Hood: If untreated, or not adequately treated, in the worst case the cornea gets ongoing inflammation and then basically can get scarring. They can get a breakdown of the surface of their cornea, and then they can sometimes get a secondary infection, like a bacterial infection of the cornea. As that process goes on, they can just get more and more scar tissue that accumulates. They can also get new blood vessels that grow into the cornea, and normally there aren’t any blood vessels there. Because this is a disease that can actually wax and wane over many, many years, people can be fine for some time and then it flares up and it worsens. So, these people, oftentimes, will need to be treated for a long period of time.
When there’s scarring, what is the treatment at that point?
Dr. Hood: We want to make sure all active inflammation resolves. So, we still will treat them with eye drops. We want to be sure all active inflammation is resolved and quiet. Then if we think that there’s no active inflammation, we can consider corneal surgery if there is significant scarring that limits their vision. Now in some patients, a contact lens may be enough to treat some mild scarring if they have irregular astigmatism or shape caused by the scar tissue. But the only way to actually treat the scar tissue once it’s actually a formed scar is to surgically remove that scar with a cornea transplant.
Talk to me a little bit about that for our viewers who are not familiar with what’s involved with a transplant.
Dr. Hood: A cornea transplant is a fairly routine surgery nowadays for treating different disorders of the cornea. We now actually have many different types of corneal transplants we can do depending on what layer of the cornea is affected by the disease process. People that have shingles of the eyes mostly going to be scarring in the sort of middle part of the cornea called the stroma. In that case, we can typically do a full-thickness cornea transplant called penetrating keratoplasty to remove scarring around the area of their cornea– typically about eight millimeters. Then we use a donor person’s cornea, someone who’s died and donates their eye. We can then transplant that into position using typically about 16 sutures to hold it in place. Again, it takes about an hour or so most of the time. It’s an outpatient surgery. But it does require a close follow up to make sure that everything heals well, and the cornea transplant does well in the recipient.
If it’s an outpatient surgery, are they under?
Dr. Hood: We can do it under general anesthesia, we can actually do with people awake, believe it or not. We can just relax them and numb around their eye and, again, we can do it in that case, with people awake in some cases.
Wow. And you said it takes just about an hour?
Dr. Hood: About an hour to do the surgery – yes.
How long is and what is recovery like? How long does it take before people can regain vision?
Dr. Hood: Depending on how much scarring there was within a week or two they could have improved vision if there was a lot of scarring of the cornea. But the new cornea, when it’s transplanted, always is going to have some swelling to it. So, we’ve got to give time for the swelling to go away for the vision to improve. Typically for the first several months after surgery, the vision is gradually improving kind of every couple weeks, and every month or so they’re noticing some improvement. Then, after several months, we start to selectively remove sutures for most patients. We actually do scans of the cornea to look at the shape and, oftentimes, will be a slightly irregular shape because of the sutures. We can selectively remove the sutures that are causing astigmatism or tightness that are causing a shape abnormality of the cornea. So, every visit that they come to the office, we will remove a couple of sutures and over the course of typically even up to a year, we’ll be removing sutures to get their vision improved.
So, this is a slow process – the recovery?
Dr. Hood: I tell patients the full recovery from a transplant is up to a year to get the full vision recovery. Now, in terms of their lifestyle and things that they’re doing, they can usually return to normal activities way before that. But then, the maximum vision recovery can take up to a year, depending on how things go.
Now you and Kellogg report of a study that looked at transplantation– can you tell me about that?
Dr. Hood: We did, yes, we published this recently. We looked at our outcomes and the largest study to date looking at the outcomes of cornea transplant in patients that have had shingles-related complications in the cornea.
And what did you find?
Dr. Hood: We found that most people did very well. So, these eyes are actually at very high risk for transplant because many of them actually have a numb, or neurotrophic cornea, which actually, goes very commonly with the shingles virus that affects the eye. They oftentimes had a lot of blood vessels growing into the cornea, which is often thought to be a risk factor for rejection or failure of transplants. So, these are patients that before surgery would be considered pretty high risk for transplant in terms of failure or rejection of their transplant. We followed them for many years– many of them up to five years or more and the vast majority of transplants did remain clear over time. Vision improved for many patients at the one-year mark after surgery. Now, as time went on, the vision improvement was not sustained. We think some of that may be because of other eye diseases that the patients would have had that may be unrelated to their shingles virus.
So, in other words, they were 20/20 and then lost vision?
Dr. Hood: Yeah, it’s hard because it’s a study that doesn’t look at individual patients, it looks at kind of an average vision across all patients. So many patients did maintain a very good vision throughout the duration of the study. Some patients lost vision, presumably– we didn’t look at the detail of this, but presumably from other diseases of the eye because their transplant remained clear. That was our primary outcome focus– were the transplants clear? And I think 70% were clear, even going up to five years after surgery.
You and your colleagues are also doing something that’s not just for corneal transplants related to shingles virus to reduce the – is it the numbness?
Dr. Hood: Yeah, it’s actually to get sensation back to a numb cornea.
Can you explain that?
Dr. Hood: Yeah, so it’s called neurotization of the cornea, and it’s a relatively new procedure where, basically, cornea sensation can be restored in patients that have a numb cornea. The shingles virus is one of the most common reasons for having a numb cornea. There are other reasons as well, from surgical causes, to even congenital causes of that but a numb cornea, actually, is not a good thing. The cornea actually has a lot of trouble maintaining a healthy surface and preventing scarring without normal sensation. So, basically, if we want to restore sensation to a cornea, in this surgery, we can borrow sensation, typically from the other nerve that serves the other eye. We can actually get a nerve graft and bring that down to the affected eye– to the numb eye. Now the nerve actually has to regrow down that new nerve transplant, so it takes, again, up to a year for the sensation to be restored to a cornea. But that’s a procedure that is relatively new and offers hope for people that have complications from a numb cornea.
That was my next question– what is the benefit for people that have this long-range?
Dr. Hood: So right now, we’re kind of using it for people that have already had significant complications from a numb cornea. I think that the indications will probably evolve and ideally, we’d maybe intervene earlier for people. But for people that have scarring of their cornea because of a numb cornea, by restoring sensation we could then, we hope, do a cornea transplant some time afterwards that would have a much higher chance of success because now that new cornea transplant will have sensation, they won’t have recurrent problems with the numb cornea.
Is that something that you’re currently studying?
Dr. Hood: Yeah, we’re doing these surgeries as the need arises and we’re hoping to eventually publish our results and share what we’ve learned from this.
Is there anything I didn’t ask you that you would want people to know about the cornea transplants?
Dr. Hood: No, I think you’ve really captured a lot of the essence of what we do with transplants and for shingles.
And how many do you do?
Dr. Hood: Well, our study was 54 patients and that was over the course of many years of looking back at our records and at our patients. So, it comes up fairly often. This is, unfortunately, a pretty common disease. Luckily, with good management, many of these patients can avoid transplant. Again, many of them have relatively mild scarring that can be treated with contact lenses or even glasses can get them good enough vision. So, really, these patients were the ones that had the worst of the worst vision. It comes up occasionally, intermittently, in our practice, but worldwide and in the U.S., this is a pretty common problem.
Do you have the statistics on how many people struggle with this in the United States?
Dr. Hood: Just with shingles in the eye? It’s really common. I don’t have the actual stats in my head, but shingles is very common and there actually is a very high rate of it coming out in what is called the V1 nerve, which is right around the eye. It has a propensity or desire to kind of come out in that nerve. We don’t quite understand why that is. You can look at all the nerves, you could say if it was just a random outcome, it would be in the leg part of the time and then around the trunk part of the time, but it really comes out more than you would think around the eye.
And it used to be patients in their 50s and 60s, but you said you’re seeing younger?
Dr. Hood: We definitely are.
You said 30s and 40s now?
Dr. Hood: We are. Actually, that reminds me of something that may be worth mentioning, the shingles vaccine is extremely important and can actually prevent all these complications, we think. So, there is a new vaccine that has actually been proven to be even more effective than the older vaccine.
What’s that?
Dr. Hood: The new one is called Shingrix. The CDC has actually recommended now that even people who have had the older vaccine, called Zostavax, receive the new shingles vaccine because it’s so much more effective at preventing recurrences of shingles.
And is it correct to say that if they’ve had shingles, they can’t get these? It’s too late for this…?
Dr. Hood: No, it’s a little bit of controversy. I think the recommendation is still to receive the shingles vaccine– not when you’re having acute inflammation in your cornea, but we still think that the vaccine would be effective, even if you’ve had shingles, to prevent it because people can get shingles multiple times.
Interview conducted by Ivanhoe Broadcast News.
END OF INTERVIEW
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