Patients who have corneal staining and little to no symptomatic discomfort, often described as “stain without pain,” are seen in our offices daily. Some corneal findings may be attributed to soft lens wear, others may be experiencing multipurpose solution hypersensitivity, and even non-contact-lens-wearing aggressive eye rubbers amid allergy season may present with stain and no pain. There is, however, a small group of patients who have neurotrophic keratopathy (NK) of which we must be wary.

NK is a rare corneal degenerative condition secondary to impaired trigeminal nerve innervation and may present in those who have a history of diabetes, chronic contact lens wear or post-herpetic infections (Dua et al, 2018). NK begins with corneal staining and progresses to a persistent epithelial defect (PED) that can advance to cornea perforation (Bonini et al, 2018). The corneal protective abilities of scleral lenses (SLs) can be effective in treating patients who have PEDs, especially when overnight lens wear is combined with a drop of preservative-free antibiotic in the lens reservoir (Khan et al, 2019). However, differentiating epithelial defects secondary to NK is key, as SLs alone may be insufficient in preventing disease progression. Be suspicious of NK if corneal sensitivity is decreased or absent; this can be verified in-office with a cotton wisp test prior to instillation of anesthetic drops.

NK-related corneal damage often does not respond to conventional dry eye treatment, as the problem lies in the central nervous system. Cenegermin-bkbj ophthalmic solution 0.002% is the only drug approved by the U.S. Food and Drug Administration for the treatment of NK. Cenegermin has shown high rates of healing and good long-term outcomes among patients who have non-responsive corneal defects (Pflugfelder et al, 2020).

Case Study

A 56-year-old black man presented with a chief complaint of progressively worsening vision. Entering visual acuities through habitual spectacles were 20/200 OD and 20/40 OS. He reported no pain and was interested in updating his spectacles. His ocular history had a significant risk factor for NK: recurrent herpetic infections OD. Corneal sensitivity was absent; a central defect without infiltrate was noted (Figure 1).

Preservative-free antibiotic drops and artificial tears along with lid taping were prescribed with follow up, and a prior authorization was submitted for cenegermin. By week two, the epithelial defect had decreased in size significantly, although corneal irregularity remained (Figure 2).

 He struggled with lid taping and opted to be fit with a SL. No further improvement was noted despite daily SL wear. During the fitting process, the cenegermin use was approved; the patient will begin the eight-week treatment soon. Hopefully, the remaining corneal epitheliopathy will resolve with cenegermin use.

NK patients present with atypical ocular surface disease findings and often do not respond to traditional dry eye treatments. SLs may prevent future complications. Patients who have persistent corneal defects, especially in the setting of NK, must understand the importance of prompt follow up with any ocular changes, as future epithelial defects can progress to infection or corneal perforation if left untreated. CLS

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