Corneal Nerve Pathway Function in Individuals with Dry Eye Symptoms

Abstract

Dry eye (DE) disease is a multifactorial, chronic condition with a prevalence of 5% to 30%. 1 Stapleton F. Alves M. Bunya V.Y. et al. TFOS DEWS II Epidemiology Report. Ocul Surf. 2017; 15: 334-365 Crossref PubMed Scopus (723) Google Scholar Dry eye symptoms are a frequent presenting report to eye clinics and can include sensations of dryness, as well as ocular pain (described as burning, aching, and irritation) and vision-related disturbances. Dry eye symptoms affect quality of life because they reduce the ability to work and carry out activities of daily living. 1 Stapleton F. Alves M. Bunya V.Y. et al. TFOS DEWS II Epidemiology Report. Ocul Surf. 2017; 15: 334-365 Crossref PubMed Scopus (723) Google Scholar Of note, DE symptoms are often disparate from DE signs, which include decreased tear production, increased tear evaporation, and inflammation, among others. One explanation for the disparity is the variable contribution of corneal nerves, which are responsible for touch, pain, and thermal sensation in the eye, to the pathophysiology of disease. In fact, the updated definition for DE includes neurosensory dysfunction as a contributing facet, in addition to tear and ocular surface abnormalities. 2 Craig J.P. Nichols K.K. Akpek E.K. et al. TFOS DEWS II Definition and Classification Report. Ocul Surf. 2017; 15: 276-283 Crossref PubMed Scopus (941) Google Scholar However, it is not known how many individuals with DE symptoms have nerve abnormalities as a contributing feature of disease. To address this knowledge gap, this research aimed to characterize corneal nerve pathway function in individuals with DE symptoms and examine the relationships between metrics of nerve function and DE parameters.