Abstract
Purpose: :
To determine the impact of blinking on tear menisci in aqueous tear deficiency (ATD) dry eye patients using optical coherence tomography (OCT).
Methods: :
Twenty-one clinically diagnosed ATD patients and 26 normal subjects were recruited. The upper and lower tear menisci of one randomly selected eye of each participant were imaged during normal and delayed blinking sessions using a real-time OCT. The height of the upper (UTMH) and lower (LTHM) tear menisci was obtained.
Results: :
LTMH measured before and after blinking showed significantly increased in both groups during delayed blinking compared to normal blinking (paired t-test, P<0.05). While no significant differences of LTMH were found between groups during normal blinking, significant lower LTMH was found in ATD compared to control group during delayed blinking (independent t-test, P<0.05). The blinking output (the difference before and after blinking) was significantly increased during delayed blinking than normal blinking in ATD patients (P<0.05), in contrast to no significant difference in controls (P>0.05). During normal blinking, the blinking output was found significantly smaller in ATD patients than controls (P<0.05). However, during delayed blinking, no significant difference were found in the output between groups (P>0.05). Opening output (the changes before and after eye opening period) in LTMH was increased during delayed blinking in both groups (P<0.05). During normal blinking, opening output was smaller in ATD (P<0.05), however, during delayed blinking, the opening output showed no significant differences between groups (P>0.05). Significantly larger UTMH was found during delayed blinking compared to normal blinking (P<0.05). Blinking output in ATD patients was found larger during delayed blinking than during normal blinking (P<0.05). Opening output showed significantly greater decrease in ATD (P<0.05).
Conclusions: :
ATD patients appeared to have less tear dynamics during normal blinking and smaller increase of the tear volume during delayed blinking. OCT is a promising tool for studying human tear system.
Keywords: cornea: tears/tear film/dry eye • anterior segment