Decrease of tear break-up time at Japanese eye clinics during five consecutive years

The aim of this retrospective chart review study was to evaluate the 5-year trend of ocular surface examination results in participants who visited the eye clinic from 2015 to 2019, underwent corneal and lacrimal examinations, refraction, and intra-ocular pressure measurements, and reported six dry eye-related symptoms. A total of 1468 patients were analyzed. Tear break-up time (BUT) decreased continuously for five consecutive years: 4.76 +/- 1.84 s in 2015, 4.57 +/- 1.70 s in 2016 (p = 0.999, vs 2015), 4.35 +/- 2.06 s in 2017 (p = 0.662), 3.83 +/- 2.18 s in 2018 (p < 0.001), and 3.63 +/- 2.10 s in 2019 (p < 0.001). The decrease of BUT was more prominent in women than men (p < 0.001) and the correlation coefficient between calendar year and BUT was greater in women than men (p = 0.002). Schirmer test value, strip tear meniscometry value, and corneal staining score did not exhibit significant changes. Prevalence of blurring, photophobia, and pain increased toward 2019 among symptoms surveyed (eye fatigue, blurring, photophobia, dryness, irritation, and pain) and regression analysis indicated blurring (p < 0.001), photophobia (p < 0.001), and pain (p < 0.001) were correlated with BUT. In conclusion, BUT decreased continuously for five consecutive years from 2015 to 2019 and was associated with dry-eye related symptoms.