Changes in Corneal Subbasal Nerves after Punctal Occlusion in Dry Eye Disease

To evaluate corneal subbasal nerve plexus by in vivo confocal microscopy (IVCM) following punctal occlusion in patients with moderate to severe dry eye disease (DED).

Patients with grade 3 or 4 severity of DED based on Delphi Panel dry eye severity grading scheme were enrolled in the study. Permanent inferior punctal occlusion was performed. A comprehensive ophthalmic evaluation, including Ocular Surface Disease Index (OSDI) questionnaire, tear break-up time (TBUT), corneal fluorescein staining, conjunctival Rose bengal staining, Schirmer's test, and corneal sensation by Cochet-Bonnet esthesiometry, were performed at baseline, and 1 and 3 months after punctal occlusion. Furthermore, density and number of corneal subbasal nerves were evaluated by IVCM.

Forty-one eyes of 23 patients with a mean age of 46.3 ± 9.0 years were enrolled. Corneal fluorescein staining, Rose bengal staining, and TBUT significantly improved at 3 months following punctal occlusion (p < .015). Corneal esthesiometry significantly increased at both postoperative visits (p < .03), and OSDI scores improved only at 3-month follow-up (p < .005). Nerve density and total number significantly increased 3 months after punctal occlusion (p < .045). Baseline nerve density had significant correlations with TBUT, fluorescein staining, Rose bengal staining (p < .012), but not with esthesiometry, Schirmer scores, or OSDI scores (p > .329).

Corneal subbasal nerve density and total number increased following punctal occlusion in patients with moderate to severe DED. These findings were associated with improvements in corneal sensation, and signs and symptoms of DED. This emphasizes the effect of punctal occlusion in regeneration of corneal subbasal nerve plexus.