Abstract
Purpose :
To investigate the changes in sensory responses to suprathreshold corneal stimuli following a 2-week interruption in contact lens wear (CL) among symptomatic CL wearers
Methods :
49 adapted CL and 15 non-CL wearing normal subjects participated in the study. CL wearers were subdivided into symptomatic and asymptomatic groups based on comfortable wearing time (< 8 hours) and CLDEQ-8 score (≧14). Based on each subject’s threshold, pneumatic stimuli (delivered using a computerized Belmonte esthesiometer) ranged from threshold to approximately 2 times threshold and were equally divided into five levels, Stimuli were presented in a random order with a minimum of a one minute interstimulus interval. The magnitude of the sensory response to stimuli was assessed for intensity, coolness, irritation and pain, using a 0 (none) to 100 (very strong) scale. Measurements were taken at baseline (with habitual CL wear), after 2 weeks of no-CL and after restarting CL wear for 2 weeks.
Results :
There was a group difference in the estimated magnitude of intensity and irritation (p=0.007 and p<0.001, respectively). Post hoc tests showed that the magnitude of the symptomatic group was significantly higher compared to the control and asymptomatic groups (Tukey HSD all p≤ 0.012). The group difference in estimated magnitude of irritation was dependent on visits (p< 0.001); the magnitude of irritation in the symptomatic group was significantly lower following 2-week of no-CL compared to the baseline (p=0.001) and tended to increase after wearing CL for 2 weeks compared to no-CL (p=0.057).
Conclusions :
The symptomatic contact lens wearers showed an enhanced responsiveness to supra-threshold stimuli at baseline, reporting stronger intensity and greater irritation. The magnitude of irritation decreased, following a 2-week interruption in contact lens wear, but worsened after 2-week resuming CL wear.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.