Abstract
Purpose :
To investigate the association between CLDEQ-8 classes, blink frequency during digital device use, tear film metrics, and a metric that emphasizes blinks that occur after the tear film has destabilized.
Methods :
A bilateral, dispensing, randomized, double-masked 2x2 cross over study with a 2-week washout was executed. Two silicone hydrogel investigational soft contact lenses were employed, differing only by hydration method. The study included 6 visits: a baseline evaluation and lens fitting, a 1-week follow-up (FU) after 8 hours of lens wear, and a 2-week FU after 8 hours of lens wear. After a 2-week washout with habitual contact lens wear, this was repeated using the second investigational lens. A total of 37 subjects completed the study. At both 1-week FUs, 2 measures of tear stability were evaluated using the Oculus Keratograph 5M and a customized dynamic iDesign wavefront system, and the interblink interval (IBI) was measured while the subject watched a 5-minute video on a tablet. During this measurement, a video of each subject was recorded and analyzed using custom software to yield the IBIs. Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) was also administered at these 1-week FUs, however this questionnaire is not validated at the 1-week wear timepoint. Classes were defined using CLDEQ-8 scores, as follows. Poor and fair ≥ 15; 7 < good and very good < 15; excellent subjects ≤ 7.
Descriptive statistics, by class, were calculated for the IBI, NIKBUT, wavefront RMS, and ocular protection index (OPI) calculated using the NIKBUT and IBI.
Results :
Mean or median IBI and mean NIKBUT, plotted by class, did not point to a relationship between the metrics and classes. Plots of the wavefront RMS suggested an increase of RMS and plots of the OPI suggested a decrease in OPI with increasing symptom class.
Conclusions :
Combining the NIKBUT tear stability and IBI (OPI metric) appeared to provide better agreement with symptom classes defined by CLDEQ-8 as compared to using IBI or NIKBUT alone. Further investigation of dryness symptoms and discomfort during digital device use, and the interaction between the blink frequency and tear film metrics are warranted.
This is a 2021 ARVO Annual Meeting abstract.