Modified blink dynamic index predicts activity and severity in patient with facial nerve palsy

Recovery of the Ratio of Closure Time during Blink Time in Lacrimal Passage Intubation

(1) Background: We aim to find a novel blink parameter in nasolacrimal duct obstruction (NDO) patients and analyze parameters that could reflect subjective symptoms and objective indicators at the same time through a blink dynamic analysis. (2) Methods A retrospective study was conducted with 34 patients (48 eyes) who underwent lacrimal passage intubation (LPI) and 24 control groups (48 eyes). All patients' blink patterns were measured using an ocular surface interferometer before and after LPI, including total blink (TB) and partial blink (PB) and the blink indices blink time (BT), lid closing time (LCT), closure time (CT), lid opening time (LOT), interblink time (IBT), closing speed (CS) and opening speed (OS). The tear meniscus height (TMH) was measured, and the questionnaire "Epiphora Patient's Quality of Life (E-QOL)," which includes daily activity restriction as well as static and dynamic activities, was completed. (3) Results: Compared to CT and the ratio of CT during BT (CT/BT) in control (89.4 ± 20.0 msec, 13.16%), those in NDOs were longer (140.3 ± 92.0 msec, 20.20%) and were also related to TMH. After LPI, CT and CT/BT were recovered to 85.4 ± 22.07 msec, 13.29% (p < 0.001). CT and CT/BT showed a positive correlation with the E-QOL questionnaire score, particularly with dynamic activities. (4) Conclusions: CT and CT/BT, which are objective indicators associated with subjective symptoms of patients, are considered new blink indices for the evaluation of NDO patients with Munk's score.