Here’s a look at some of the lectures presented during the Keratoconus Essentials and Corneal Essentials symposia.
Imaging Aids in Early Keratoconus DiagnosisTopography and tomography enable the early diagnosis of keratoconus (KC), Kenneth A. Beckman, MD, explained during his “Diagnosis of Keratoconus: Topography and Tomography Pearls,” lecture, which opened the track.
Specifically, the imaging displays localized areas of steepening, regular astigmatism, asymmetric, mustache, sagging, skewed or truncated bowtie, skewed radial axis and asymmetry between the two eyes, posterior elevation of the cornea, crab claw appearance or a bell shape — all classic signs of keratoconus, he said.
“We tend to see the cones developing as early as the early teens, but it could be even younger, so I think [it’s important] to look for scissoring, failure to correct [with spectacles] and big changes in astigmatism or anything unusual like that to get patients evaluated with imaging.”
3D Mapping Could Enable Focused Keratoconus TreatmentsDuring her lecture, “Diagnostics of Keratoconus: Future Diagnostic Technologies,” Elizabeth Yeu, MD, discussed how 3D imaging technology could allow practitioners to see the exact location of the increased elasticity in the keratoconus patient, enabling focused treatments.
“Looking at depth-dependent analysis will be important for refractive surgery [and] monitoring [the] effectiveness of collagen cross-linking,” she offered.
Dr. Yeu also discussed the potential benefit of bow microscopy in identifying subclinical keratoconus:
“The elasticity being different creates different levels of light scatter, and the frequency of keratoconic eyes is much lower when compared to the more normal corneal population,” she explained.
Cross-linking Patients Should be Followed TemporarilyPatients who undergo corneal cross-linking (CXL) should have ongoing follow-up, especially in the first two years, noted Kathryn M. Hatch, MD, ABO, in her lecture, “Crosslinking: Current State of the Art.”
“Once they seem stable, they can continue to be followed yearly and be co-managed with referring optometrists or opthamologists, assuming that they have the appropriate diagnostic testing, including tomography,” she explained.
Additionally, Dr. Hatch pointed out that all 50 states now have more than six plans that cover the FDA-approved epi-off procedure and that Avedro’s ARCH Program (https://bit.ly/2LXmAYl) can assist with coverage for patients, including those who have state insurance.
Intacs Success Based on Patient Candidacy/ExpectationsIntacs (CorneaGen) can be ideal for keratoconus patients who struggle with contact lens intolerance, those who are anisometropic, those who have good corneal clarity and want to avoid keratoplasty and those who have failed CXL, explained W. Barry Lee, MD, during his lecture “Intacs for Keratoconus.”
“We don’t want to use Intacs in patients with corneal scarring, such as hydrops, or severe apical scarring in striae. [Also], any patient’s Kmax that is over 50 is not going to get much benefit from Intacs,” he said. “You want to make sure the central thickness is not less than 400 microns, and you certainly want to make sure that you look at your tomography map and that the pachymetry values of the peripheral cornea, where the steep axis is or wherever you’re going to make your incision, has enough thickness. Then, obviously, there’s an age limitation, which is 21.”
Dr. Lee added that it’s important to set patient expectations that Intacs are not a vision recovery treatment, but rather devices that provide structural support to the cornea and aid in biomechanical remodeling.
“Because visual acuity is not significantly improved with this technology, you might want to think about doing combined techniques just to get some improved effect. That’s where things like cross-linking with Intacs, cross-linking with conductive keratoplasty and Intacs and Intacs with cross-linking and an implantable collamer lens to correct myopia might be the way to go,” he offered. “Or even doing topography-guided photorefractive keratectomy down the road. By itself, Intacs don’t really do a whole lot for vision or astigmatism reduction long-term.”
Photorefractive Keratectomy Post CXL Can Improve VisionPatients who undergo photorefractive keratectomy (PRK) after first going through CXL can achieve improvements in vision, says William Trattler, MD, in his lecture, “Laser Vision Correction in Patients with Keratoconus.”
“The more time you wait, the better the [corneal] shape will often be. So, I typically recommend my patients wait 1 year, 2 years, 3 years and 4 or 5 is even better,” he explained. “It all depends on the patient, their hobbies or activities and how much improvement we get as well ... But the more a patient waits, the more potential improvement they can achieve.”
Dr. Trattler discussed that combining CXL and PRK as one procedure is an option, but the advantages for separating the two procedures also include avoiding the risk of haze and delayed epithelial healing.
“CXL as a primary procedure has advantages because we can see an improvement in corneal shape over time, and PRK is easier to perform when the corneal shape is less irregular,” he offered. “And topo-guided PRK does hold promise, but you could also consider wavefront-guided laser-vision correction.”
Remember: RGP Lens Reveals True Culprit of Visual ComplaintsAs there is a large overlap in visual complaints (e.g. glare and reading difficulty) related to corneal ectasia, keratoconus and cataracts — and each cause requires different intervention — determining the true cause of these visual complaints is important. This is where an RGP lens comes in, said Brandon D. Ayres, MD, during his lecture, “Cataract Surgery Considerations in Keratoconus.”
“Make sure the patient is out of their contact lens, and then use an RGP lens, which separates the cornea tissue from the cataract,” he said. “If the patient’s vision improves, you can be pretty well be assured that the cornea is to blame and not the lens.”
He added that many advocate for CXL in keratoconus patients who have cataracts because the corneal flattening that results from the procedure may lead to a better refractive result post-cataract surgery.
In terms of IOL selection, Dr. Ayres said that in cases of astigmatism in relatively mild to moderate keratoconus patients, a toric IOL can be used. However, these patients should be made aware that if they’re astigmatism is higher than the IOL can correct, the procedure will be astigmatism-reducing, not eliminating.
Treatment Approach Can Resolve Neurotrophic KeratitisIn the opening lecture, “Neurotrophic Keratitis,” Marjan Farid, MD, ABO, detailed a treatment approach for neurotrophic keratitis:
- Discontinue drops that can cause additional ocular toxicity. “I want to switch any pressure-lowering drops to preservative-free versions; stop topical non-steroidal agents,” she explained. “These patients usually come in with a bag of drops that they have tried in the past. Make sure to sit down with them and go through those and get rid of anything that’s toxic to the ocular surface.”
- Start antimicrobials. Dr. Farid does this to prevent a secondary bacterial infection, though she doesn’t prescribe topical antivirals due to the additional toxicity they can cause.
- Treat the inflammation. Dry eye disease, blepharitis and stem cell deficiency compound “the entire picture,” so they need to be addressed, she said. “If [the patient] looks very inflamed, I have a short, relatively low threshold for putting these patients on some topical steroids short-term,” she said. “I think doxycycline is great for patients with concomitant lid margin disease ... We want to improve the tear milieu. Preservative-free, artificial tears and serum drops are great [for this].”
- Prescribe cenegermin-bkbj (Oxervate, Dompe). FDA-approved for neurotrophic keratitis in early 2019, this is recombinant human nerve growth factor, which is applied six times per day for an 8-week course. “Essentially, the way it works is it’s structurally identical to endogenous nerve growth factor. What endogenous nerve growth factor does is it maintains the corneal integrity by three mechanisms. It plays a role in nerve function, stimulation, regeneration. It also plays a role in keeping the epithelium healthy. And finally, it plays a role in improving the secretion of tears. So really, by these three mechanisms, it helps support the ocular surface,” Dr. Farid explained.
- Employ adjunctive therapy. These include autologous serum (promotes epithelial regeneration and healing), amniotic membrane (for epithelial migration and attachment) and bandage or scleral contact lenses (for chronic epithelial breakdown).
Consider Testing Red Eye Patients For COVID-19Given that adenovirus-caused epidemic keratoconjunctivitis looks an awful lot like conjunctivitis, which can be a symptom of COVID-19, Karolinne M. Rocha, MD, PhD, ABO said ophthalmologists should consider testing red eye patients for the coronavirus, during a Q&A session after her lecture “Coronavirus/Adenovirus.”
“We don’t know if we’re going to see a second peak of COVID, especially during the winter time, [so] it’s definitely something we need to consider,” she explained. “I think testing is important, so we can make the diagnosis, that patient can stay home, and we can avoid that transmission.”
She added that telehealth visits for patients reporting red eye may also be a good idea to limit the possible spread of COVID-19, while recommending patients who report fever and cough contact their primary eye-care provider.
During her lecture on “Corneal Lumps and Bumps,” Clara C. Chan, FRCS, MD, went into detail about how superficial keratectomy can triumphantly eliminate Salzmann’s nodular degeneration.
Superficial Keratectomy Can Successfully Remove Salzmann’s Nodular Degeneration
“When we do a keratectomy, we do it under a topical anesthetic, just kind of getting the edge off and then peeling the lesion,” she explained. “You want a dry surface to start, get that scrape away from the actual lump itself, just so you can get the edge. You can see the nice, smooth basement membrane, so then you know that you’ve gotten rid of everything that’s abnormal.”
Dr. Chan went on to explain that the procedure can be done at the slit lamp with the patient lying supine in a procedure room or even on the laser bed. Also, she drapes to keep the eyelashes away, uses some betadine or iodine to sterilize the surface and puts a few drops of antibiotic steroid in the eye and a contact lens on at the end of the procedure.
“Usually I warn [patients] that the first 48 hours is the worst. Get over that hump, then the pain gets much better. Also, I prescribe a lot of lubrication drops and then I see them after the first week usually just to check that the epithelium has grown back fully and remove the contact lens,” she said. “Then typically I would then see the patient back about 4 to 6 weeks after they’ve tapered off their steroids.”
When asked whether there were any situations in which she would delay the procedure, Dr. Chan said that patients who are asymptomatic, don’t have dry eye symptoms, are happy with their vision, have peripheral nodules or don’t have an impending cataract may not need to undergo superficial keratectomy emergently.
“I tell these patients, ‘Let’s just watch it until a point in time where you’re uncomfortable or your vision is affected or you actually are admittedly needing cataract surgery,’” she explains.
Screen Pre-cataract Surgery Patients for Dry Eye DiseaseDry eye disease is significantly underdiagnosed in the preoperative cataract patient and it can negatively impact IOL measurements, leading to an unsatisfactory refractive outcome, so ophthalmologists should make screening for ocular surface disease a priority before the procedure, said Preeya Gupta, MD, in her lecture, “Treating Ocular Surface Disease Before Cataract Surgery.”
“Ocular surface disease is very common in patients presenting for cataract evaluation, and we must treat it prior to surgery, especially in patients with high visual expectations,” she explained. “And we should know that biometry and keratometry readings do change after treating ocular surface disease, so I’d encourage everybody to screen their patients.”
After referring to the ASCRS Preoperative OSD Algorithm, created by the ASCRS Cornea Clinical Committee (https://bit.ly/3cV91Vf) and discussing the various treatment options, Dr. Gupta stressed the importance of patient education.
“I think that the number one thing for you to do when you’re looking at these patients is to have a conversation with the patient that lets them know that they have two conditions: dry eye/MGD and a cataract, and that both create blurry vision, but one is a chronic condition and one is treated surgically,” she explained. “Once the patient sort of owns that disease process and understands that that disease process will really impact them for the rest of their life to some degree, I think it gives them more ownership in terms of having more realistic expectations.”
MD Seeking Advice on How to Tame Persistent, Stubborn Herpetic Eye DiseaseIn the lecture, “Herpetic Infectious Keratitis,” Brandon D. Ayres, MD, presented the case of a patient in his 50s with recurring and obstinate herpetic infectious keratitis.“Some patients will have recurrences that can lead to downstream complications, such as corneal scarring, cataract, glaucoma and reduced vision,” he said. “I’m happy to have any help that someone can give me with this patient.”
Some of the advice provided by the track panel: Inquire with the patient’s primary doctor as to whether the patient may have atopy, which is linked with increased immune responses, and whether the patient may have any other underlying immune system issues, in general.
To view Dr. Ayres’ case and see whether you may be able to provide any insights, visit https://ascrsvirtualmeeting.ascrs.org/live-stream/15336706/Cornea-Essentials. OM