Comparative Blink Analysis in Patients With Established Facial Paralysis Using High-Speed Video Analysis

Videographic analysis of blink dynamics in patients with chronic progressive external ophthalmoplegia, myogenic ptosis, and facial nerve palsy using smartphone camera: A comparative analysis

Background and Aims

Congenital myogenic ptosis (CMP), chronic progressive external ophthalmoplegia (CPEO), and facial nerve palsy (FNP) are among the disorders which can seriously affect the blink dynamics of patients. Smartphone videography is a simple, convenient, and inexpensive way to capture eyelid movement. This study has measured and compared a variety of blink dynamics in these patients compared to healthy controls using 2-dimensional smartphone videography to enhance the utility of this method in both clinical and research settings.

Methods

A total of 30 adult participants with a complaint of impaired eyelid movements including 10 with CMP, 10 with CPEO, and 10 with unilateral FNP, as well as 10 healthy controls were recruited. Using a smartphone camera with a resolution of 240 frames per second in 720 p, various blink dynamics were measured.

Results

All case groups had significantly lower values of peak and average closing velocities, average opening velocity, and palpebral aperture and significantly higher values of eyelid closing duration, compared to controls. FNP participants also had significantly lower values in the full blink rate and peak opening velocity (POV) measures, and CPEO patients showed significantly lower values in the POV. Other measures were not statistically significantly different compared to healthy controls.

Conclusion

Our results indicated that all patients with CMP, FNP, and CPEO had different blinking dynamics compared to healthy controls, which is consistent with previous studies. Smartphone videography has achieved sufficient resolution and frame-rate to provide valuable information and anatomic details for clinical and research purposes. Further studies could utilize smartphone videography for further investigation and confirmation of the methodology in various conditions.

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

Purpose

We analyzed the dynamics of blink and defined the blink index in facial nerve palsy (FNP) patients using an ocular surface interferometer associated with clinical characteristics and clinical progress.

Methods

In total, 49 patients were enrolled this study. All patients were tested using an ocular surface interferometer which is used to measure blink patterns (total blink (TB), partial blink rate (PBR)) and blink dynamics (blink time (BT), lid closing time (LCT), closure time (CT), lid opening time (LOT), interblink time (IBT), closing speed (CS), and opening speed (OS)) using 600 frames recorded over 20 s. The distance of lagophthalmos and modified interpalpebral fissure (IPF), which was defined as the actual moving distance of the upper eyelid, subtracting the distance of lagophthalmos from IPF, was measured using the ImageJ program. The types of FNP were "idiopathic" (Bell's palsy) and "surgical" (following the neurosurgery). Patients were classified into "acute" and "chronic" based on the duration of 6 months from the onset time of FNP. The clinical characteristics were classified into mild or severe according to the severe degree of exposure keratopathy-as "severe" if treatment such as tarsorrhaphy and gold plate insertion was required.

Results

Reduced MRD1, brow height, and modified IPF and increased lagophthalmos were noted in the palsy side. LCT was longer and CS, modified CS, and modified OS were shorter in the palsy side. The LCT was longer and the modified CS was shorter in idiopathic patients with acute onset and with clinically severe. IBT was increased in idiopathic patients with clinically severe.

Conclusion

Analyzing the blink patterns and blink dynamics, this study suggests meaningful indicators among blink profiles and dynamics, LCT, and modified CS based on modified IPF. It was more associated in the idiopathic type than in the surgical type of FNP patients. The modified CS can be a useful tool for evaluating the activity and severity indicator of FNP.