Decrease in total corneal nerve density and presence of activated dendritiform cells by in vivo confocal microscopy in patients with dry eye disease is correlated with increased levels of pain

Abstract

Purpose : In vivo confocal microscopy (IVCM) allows for visualization of corneal nerves and immune/inflammatory cells in patients, which may aide in treatment decisions. Herein we aim to correlate IVCM findings with symptoms reported in the Ocular Surface Disease Index (OSDI) or Ocular Pain Assessment Survey (OPAS).

Methods : This retrospective cross-sectional study, included patients with dry eye disease (DED). From three representative IVCM images, the number of dendritiform cells (DCs) per image (DC density) was quantified by one masked observer using Image J. Average total nerve density was quantified using NeuronJ. IVCM parameters were correlated to symptoms by OPAS and OSDI. Spearman correlations were completed with Bonferroni correction.

Results : The median age of the DED group (n=109) was 57.8 years (IQR: 26.7) and 79.8% were female. Decreased total nerve density was significantly correlated to increased level for average pain over the last 2 weeks (r= -0.365, p = 0.008). Increase in DC size (a marker for activation) was correlated with increased levels of worst pain in the last 24 hours (r=0.385, p = 0.005), worst pain in the last 2 weeks (r=0.419, p = 0.003), and average pain over the last 2 weeks (r=0.509, p <0.001). Increase in DC dendrites was correlated with higher levels of worst pain in the last 2 weeks (r=0.414, p = 0.003) and average pain over last 2 weeks (r=0.506, p<0.001). There was no significant correlations with DC density.

Conclusions : This study shows that DED patients with decreased total corneal nerve density and activated DC have a higher likelihood to experience chronic pain.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.