Eyeworld

68 | EYEWORLD | WINTER 2026 C ORNEA is important, especially in patients with certain diagnoses like diabetes, those with past herpetic disease, etc. While cotton wisps or dental floss to test for corneal sensitivity are readily available, there are more formal tests, like the Cochet-Bonnet Aesthesiometer or Corneal Esthesiometer Brill (Brill Engines), the latter of which Dr. Gupta said is more commercially available than the Cochet-Bonnet. The Cochet-Bonnet is a quanti- tative test that gives an actual number for the patient's corneal sensitivity. Things like dental floss or a cotton wisp are qualitative—checking if patients have sensation or if it's reduced. One of the first things Christopher J. Rapua- no, MD, looks for are predisposing factors for NK, and one of the highest is diabetes. Brain surgery can also cause terrible NK, he said. Another factor is eye surgery like multiple glau- coma or retina surgeries, and of course, many corneal surgeries including refractive surgeries, can cause it, too. Lastly, soft contact lenses, particularly chronic soft contact lens wear, can cause NK. That is why taking a detailed history is so important. A thorough slit lamp exam is helpful, he said. Patients may be coming in for some type of ocular surface problem, and the referring doctor may not suspect NK. One of the problems when checking for corneal sensation, Dr. Rapuano said, is that oftentimes patients have gotten numbing drops, and it can take a while for those to lose their effect; most patients aren't sitting in the office long enough after anesthetic drops to have their corneal sensitivity checked accurately. Many of his patients are now also getting an iCare tonometer (Icare) check before he sees them, so they don't get numbing drops, and this makes it easier for him to check the corneal sensitivity. Dr. Rapuano said it's important to rule out other problems, like other ocular surface disease issues. "Usually, we'll get a Schirmer's test, flu- orescein staining, and lissamine green staining on these patients," he said. It's also important to check for meibomian gland disease, and you want to rule out any other eyelid disease. Dr. Rapuano noted how important it is to flip the lids to check for any other conditions. "Even if I think there's NK, I want to know if there are other conditions going on, too, especially exposure keratopathy, which often goes along with NK." "It seems like NK weaves its way into al- most all of the diagnoses that we treat and see in the office," said Brandon Ayres, MD. "When many people think about a neurotrophic ulcer, they might think about a patient who absolutely can't feel anything, but neurotrophic keratitis implies that there is reduced or abnormal sen- sation. That's why it's important to keep a high index of suspicion." Dr. Ayres gave the example of a patient who is diabetic, has a history of viral keratitis, multiple surgeries, LASIK or contact lens wear, and/or just dry eye. "In these cases, you need to see if there is a component of neurotrophic keratitis," he said. The baseline is to do corneal sensation. In the office, if you have any suspicion of NK, it's anything that can touch the cornea. Dr. Ayres commonly uses unwaxed dental floss. Dr. Ayres recently published a study relating to this topic, which used a Corneal Esthesiom- eter Brill, though he noted that not everyone has this tool. "I think expecting people to go out and buy an actual esthesiometer isn't realistic," he said. If the sensation is reduced, you have to get your own normative database setup. You have to look at someone who's not neurotrophic and how they respond with light touch, so that you can tell if someone has reduced sensation. This reduced sensation could be seen in one or both eyes, he said. Treatment options Treatment for NK is a stepwise approach, Dr. Rapuano said, and it depends on the stage and severity. Stage 1 is ocular surface problems like SPK, Stage 2 is epithelial defect without ulcer- ation, and Stage 3 is epithelial defect with some form of ulceration. To treat, Dr. Rapuano said he'll first stop any toxic medications. Oftentimes these pa- tients come in on a lot of different medications, including glaucoma medications with preser- vatives. Then he uses a stepwise approach with lubricating drops, gels, and ointments, on to anti-inflammatories including cyclosporine and lifitegrast. If it's NK, and they've got Stage 2 or 3 disease, Dr. Rapuano said you probably need to be more aggressive. He might use a bandage soft contact lens or place an amniotic mem- brane. He also noted serum tears, temporary or continued from page 67

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