Abstract
Purpose :
To determine the relationship between measurements of sensory function and subjective discomfort in symptomatic and asymptomatic contact lens wearers
Methods :
Forty-nine habitual soft contact lens (CL) wearers were classified as 24 symptomatic and 25 asymptomatic based on comfortable wearing time and CLDEQ-8 score. Sensory function assessments included estimates of detection threshold, responses to 20 repetitive stimuli (below-, at- and above-threshold), and to suprathreshold stimulation (at 1, 1.25, 1.5, 1.75, and 2 times of each subject’s threshold). The cooling stimuli were delivered using a computerized Belmonte esthesiometer. Measurements were taken at baseline with habitual CL wear (BL visit) and after restarting with CL wear following 2 weeks of no CL wear (2-week CL visit). The slope and intercept of the responses to repetitive stimuli were derived from a linear fit and the exponent and constant of Steven’s power law were computed for the ratings of intensity, coolness and irritation sensation to suprathreshold stimulation. Logistic regression was used to partition diagnosis into symptomatic and asymptomatic subjects, with sensory responses as predictors.
Results :
Hosmer and Lemeshow Test indicated good fit of the models (all p> 0.05). The overall percent of cases that are correctly predicted by the model was 73.5 and 95.9 for BL visit and 2-week CL visit, respectively. Threshold, exponents of intensity and irritation ratings were significant predictors at both visits (all p≤ 0.020) while the slope of responses to repetitive below-threshold stimuli was an additional significant predictor at the 2-week CL visit (p= 0.039).
Conclusions :
This study demonstrated a relationship between measurements of sensory function and subjective reported CL discomfort, supporting the role of sensory function in CL discomfort. The predictors obtained following habitual wear and after restarting CL wear following a 2-week interruption suggest a dynamic adjustment of the complex neural mechanisms involved in CL discomfort.
This is a 2020 ARVO Annual Meeting abstract.