Detection of Subclinical Neurotrophic Keratopathy by Non-Contact Esthesiometry

To analyze corneal sensitivity with a new noncontact and hand-held esthesiometer (Brill Engines, Spain) in patients with dry eye disease (DED) and patients on hypotensive drops, and to compare it with healthy subjects.

31 patients (57 eyes) with DED, 23 patients (46 eyes) with glaucoma and 21 healthy patients (33 eyes) were recruited. In all patients, corneal sensitivity was measured. Subsequently, a keratography test (Keratograph 5M, Oculus) was carried out to measure tear meniscus height (TMH), non-invasive break up time (NIBUT), bulbar redness (Jenvis scale) and corneal staining (CS, Oxford scale). Both corneal sensitivity and ocular surface parameters were compared between DED, glaucoma, and healthy subjects. Linear mixed models were constructed to utilize data from both eyes of patients. A 95% confidence level was considered statistically significant.

The mean age was 56.1±16.1 years in DED group, 69.5±11.7 years in the glaucoma group and 36.3±10.5 years in the control group. Adjusting for age and sex, esthesiometry was significantly worse in DED and glaucoma vs control group (p = 0.02 and p = 0.009, respectively). NIBUT was lower in DED and glaucoma patients (p < 0.001 and p = 0.001, respectively). Redness and CS values were higher in DED group (p = 0.04 and p = 0.001, respectively). TMH was lower in the glaucoma patients (p = 0.03).

Corneal sensitivity measured with a novel noncontact esthesiometer was reduced in DED and glaucoma patients compared to controls. In clinical practice, this esthesiometer could be an easy-to-use device to evaluate for patients with subclinical neurotrophic keratopathy.