Kaleb Abbott and Andrew Pucker are joined by Jeff Banas, an OD from Wisconsin specializing in glaucoma and dry eye, to discuss neurotrophic keratitis (NK).

The trio begin by trying to clarify what, specifically, NK is and how it develops. While classically associated with herpetic infections (HSV/HZV), the panel emphasizes that other significant causes include diabetes, ocular or neuro surgery, chronic glaucoma medication use, and severe ocular surface disease. All can damage the trigeminal nerve, leading to loss of tearing and other functions that help sustain corneal health, resulting in formation of corneal epitheliopathy or even a persistent corneal epithelial defect. Left untreated, this has the potential to progress to stromal ulceration or even perforation.

A hallmark warning sign is “stain without pain”—significant corneal staining with little or no patient discomfort. This occurs because damaged nerves fail to transmit appropriate pain signals, which Dr. Abbott likens to having a non-functioning smoke detector during a fire. Dr. Banas also points to delayed healing after corneal epithelial debridement as one warning sign of incipient NK, and also describes the clinical value of the Mackie classification of NK:

• Stage 1: Punctate keratitis, tear film instability, reduced corneal sensitivity
• Stage 2: Persistent epithelial defect
• Stage 3: Stromal involvement, corneal thinning, neurotrophic ulcer

The three ODs stress that Stage 1 is the most common, but is frequently overlooked, and that heightened awareness of early NK is critical. They emphasize the need to test corneal sensitivity with a cotton wisp or, if available, a Cochet-Bonnet esthesiometer, the gold standard in research settings (cutoff of ≤ 4.0cm indicates NK). The panel encourages all clinicians to incorporate corneal sensitivity testing, especially for dry eye patients who are unresponsive to standard treatments.

Turning to treatment, the group distinguishes between supportive therapies (artificial tears, punctal occlusion, immunomodulators, warm compresses) and regenerative therapies (amniotic membranes, autologous serum drops, Oxervate) and gives pearls for effective use of each in appropriate circumstances. Prophylactic antibiotics are recommended for Stage 2 and 3 due to infection risk, but not typically for Stage 1, they note.

Drs. Abbott, Pucker and Banas leave listeners with this key advice:

1. Test corneal sensitivity. It’s simple, quick and doesn’t disrupt clinic flow.
2. Think beyond HSV—Consider neurotrophic keratitis in any patient with corneal epitheliopathy and relevant risk factors.
3. Don’t dismiss asymmetric staining. It may signal an underlying neurotrophic component.
4. Treat early and aggressively to prevent progression to more severe stages.

The discussion reinforces that NK is likely far more common than currently diagnosed, and earlier identification can significantly improve patient outcomes.

Relevant Articles:

Neurotrophic Keratitis: Hiding in Plain Sight

Hurt Feelings

Nerve Growth Factor Treatment May Initiate Corneal Recovery in Neurotrophic Keratitis

Corneal Complications of Diabetes: What ODs Need to Know