1. Dec 03, 2019

Combined Demodex and Dry Eye Cause Reduced Nerve Density

According to a new study, patients with Demodex and dry eye disease are at greater risk for having significantly reduced subbasal nerve density. These patients will need additional attention to resolve both issues.

The retrospective study included 57 patients divided into three groups: having both dry eye disease and Demodex folliculorum blepharitis (n = 12), having only dry eye (n = 19), and controls (n = 26). All patients underwent confocal microscopy imaging of the central corneal subbasal nerve plexus with the Heidelberg Retinal Tomograph 3/Rostock Cornea Module. Examinations of the eyelid margin at the lash follicles for D. folliculorum were also conducted.

Results showed that patients in the group having both dry eye disease and Demodex folliculorum blepharitis had reduced total central corneal nerve density (15.69 ± 1.49) compared to those with only dry eye (19.63 ± 1.25; p = .0001) and controls (22.60 ± 0.77; p = .042).

This reduction in nerve density may be caused by more rubbing of the eye associated with Demodex. The rubbing causes dry eye and additional inflammation, which does not allow the nerves to heal.

The researchers plan to next compare the results with patients with early stage keratoconus to see if rubbing is the sole cause of reduced nerve density.


Pondelis N, et al. Demodex folliculorum mite density is associated with reduced cornea subbasal nerve density in patients with dry eye disease. Presented at: Association for Research in Vision and Ophthalmology; Vancouver, British Columbia; April 28-May 2, 2019.