AOA 2024: Decoding early keratoconus: The new management paradigm

Clark Chang, OD, MSA, MSc, FAAO, and Tracy Lynn Schroeder Swartz, OD, MS, FAAO, detail the best ways to detect keratoconus early, including the right technology to use at the right times, in a lecture they gave at this year's AOA's Optometry's Meeting in Nashville, Tennessee, which ran from June 19-22.

Video transcript

Editor's note: This transcript has been lightly edited for clarity.

Clark Chang, OD, MSA, MSc, FAAO:

Hi everyone, Clark Chang here. I'm the medical affairs director at Glaukos and also the director of specialty lenses at Wills Eye Hospital Cornea Service. I gave a lecture with Dr. Swartz on decoding early keratoconus.

Tracy Lynn Schroeder Swartz, OD, MS, FAAO:

I'm Tracy Schroeder Swartz. I work in a referral center in Huntsville, Alabama. My main focus is ocular surface disease, glaucoma, little bit of primary care of pediatrics thrown in there. But I enjoy referrals from my optometrists in Huntsville and northern Alabama. And I do encourage optometrists to refer to other optometrists who might specialize in services that you may not offer.

Chang:

So I want to give you some key takeaways that are my personal favorites. And the reason we put "early" in the title is because I think we no longer should be satisfied with managing or detecting patients only when they are moderate or severe, because we know from a lot of epidemiology studies that patients are being detected way too late, despite access to topography and demography. So we went through like a list of technologies that can be used, and different size on typography, and tomography, and OCT, and refractive changes, patient complaints. Obviously, feel free to check out our lecture or one of our future lectures. But what I would like to emphasize is this: retinoscopy still very important. I know that some of our younger doctors are less comfortable, or they don't have the time. They're relying on the autorefraction to start. Which is fine, but when you suspect that the patient is complaining about visual quality, not even acuity, we don't want to catch them too late that they're already visual compromises. So they have visual quality complaints, because there's some higher order aberration that's being induced from maybe even the posterior cornea and the anterior cornea is not affected yet. That's a great time to catch them, because we could do something. We could stabilize the cornea, recommend for interventions.

Swartz:

So when you're examining patients, one of the things you want to look for is refractive changes that maybe don't make sense. If you have a slow creep of myopia, even as little as half a diopter over a year, or any patient that has 2 diopters of astigmatism or more, you might want to consider getting a typography to make sure that that cornea is smooth, no signs of keratoconus, no distortion, no elevation changes, things like that. If you have a young adult that doesn't see 20/20, that's also a concern. If a patient comes into you and says, "Oh, that's just my bad eye, that's my near myopic eye," look and make sure during that exam that you have a reason for them to say that. If they don't show any signs of amblyogenic refractive error, there's no ptosis and there's no strabismus, then you might need to look for something else because it's probably not an amblyopia. You want to also listen to young adults who might complain about glare and halos at night. Those are things that we often consider symptoms of, say, cataracts, and we don't typically see cataracts in a young adult. So those are high risk signs of keratoconus. Once you identify a patient with keratoconus, it's important to monitor and remember, younger patients need to be monitored more closely than those that are older. And then as you monitor, if you do determine that they are progressing, that we want to refer for an interventional procedure like cross-linking, and try to hault that disease progression to increase their quality of life over that patient's entire lifespan.

Chang:

So taking biometry can be very important, especially those who are doing myopia management practices. That's a good one to use. Obviously, if you have typography, look for early signs of asymmetry, truncated bowtie even better if you have tomography, to look for posterior elevation changes. And eccentricity changes can be very important. I think in the future we will be able to better able to use OCT technology, that's getting better, and looking at epithelial thickness, changes, and giving us that thinning in over the apex, that thickening over the base of the cone.

Swartz:

So one of the first steps is to compare any glasses the patient brought in to your autorefraction and your manifest refraction. Because any young adult, they really should be about the same and you don't really expect a lot of changes. But if you have astigmatism changes, myopia changes, or possibly changes in the axis of the refraction, or maybe your manifest refraction doesn't equal the autorefraction — maybe the auto refraction picks up a lot more astigmatism, and then the patient kicks that out — those are all things where you might want to go, "Hey, staff member, go do typography on that patient." And also helps if you have little reminders by the machines. Like for example, if you have a little reminder bye your autorefractor that if the patient has more than 2 diopters of astigmatism, I want a typography, or things like that to help cue the staff.

So, basically, once you determine a patient has keratoconus, you want to have them back to repeat autorefraction, manual refraction, check their vision, make sure that they're seeing as well as they were seeing in the past. If you have aberrometry, that's always a good one — what you want to do is you want to look for coma — and typography if you have it. And if you just keep doing these over time, in a healthy adult, they're always going to be the same. Basically, after the age of like 20. We don't really expect a lot of change. But it'd be easy with keratoconus, you're gonna get changes. And even without a tomographer, which does allow us to look at the posterior surface, and that is where keratoconus is found initially, eventually, the patients have changes on their anterior surface. So they'll have a reduction in their vision and they may start to complain about the quality of your vision. The one thing that I look for all the time is patients that say, "No one could get my glasses, right. No one can ever get my glasses current. I hate going to the doctor because no one can ever do my glasses properly." I've literally trained my staff, that's all the patient has to say and they're getting a typography. So that's one of the things I've taught my staff to do. And then you just have to kind of keep those risk factors in the forefront of your brain, so if something pops up in clinic, you have to kind of automatically know what to do.