Contact lens and eye glass wearers with and witouth ocular symptoms: differences in corneal sensitivity, blinking, tearing and corneal surface temperature

Abstract

AbstractPurposeTo analyze corneal sensitivity, blink frequency (BF), tearing rate (TR), TBUT, and corneal surface temperature (CST) in young contact lens (CLs) and eye glass (EGs) wearers with and without ocular discomfort symptoms.MethodsEGs (n = 18) and CLs (n = 23) young subjects (18–40 years old, both sexes) participated voluntarily. CLs were classified as asymptomatic (A) or symptomatic (S) depending on their OSDI score (< 13 or ≥ 13, respectively). Corneal sensitivity to mechanical and chemical air puffs (3s duration, applied with a gas esthesiometer) and cold (4°C) saline drops was explored. Sensations evoked by each stimulus was scored with 0 to 10 VAS. BR (1 min at rest or during a task), TR (mm of wet phenol red threads, 15 s), TBUT (s), and CST (IR video thermography) were also measured.ResultsVAS values of irritation sensation evoked by mechanical and chemical stimulation (p < 0.05) were higher in CLs than in EGs while VAS values of cold sensation evoked by saline drops were similar in both groups. Although CST and TR were similar in EGs and CLs, TBUT was significantly shorter (p < 0.001) and BR was higher in CLs both at rest (p < 0.001) and during a visual task (p < 0.01). Although VAS values scored to corneal mechanical, chemical and cold stimulation were lower in CL‐S than in CL‐A, no differences were found in BR at rest or during the task, TR, TBUT and CST. Corneal sensitivity and CST were also similar in EG‐A and EG‐S, although TR (p < 0.05) and BF at rest (p < 0.05), but not during the task, were higher in EG‐S.ConclusionsResults show a reduced corneal sensitivity in symptomatic CL wearers, which suggests that corneal sensory nerve activity must be altered in a different degree in asymptomatic and symptomatic individuals, thus leading to changes in tearing and blinking regulation.Support: AEI‐ERDF SAF‐2017‐83674‐C2‐1‐R and 2‐R