Search

Purpose: To measure the spontaneous blinking metrics after blepharoptosis correction with frontalis muscle flap advancement., Methods: A video system was employed to measure the amplitude and velocity of spontaneous blinking of 24 eyelids after the frontalis muscle flap surgery for blepharoptosis correction. A control group with no eyelid disorders was also measured. The data of 13 eyelids who had frontalis slings with autogenous fascia, which were previously collected with the same method in another study, were used for comparison. Digital images were used to measure the superior margin reflex distance and the presence of lagophthalmos during a gentle closure of the palpebral fissure. Superficial keratitis was assessed by corneal biomicroscopy., Results: The mean amplitude of spontaneous blinking was 6.3 mm in controls, 2.6 mm in the frontalis flap patients, and 2.1 mm in the fascia sling group. The mean blink velocity was 133.8 mm/second in controls, 39.0 mm/second (3.7 standard error) after the frontalis flap, and 36.3 mm/second in patients with frontalis sling with fascia. For these 2 parameters, there was no statistical difference between the surgical groups, but a significant reduction when compared with the control group. No significant association was found between lagophthalmos and keratitis and the surgical procedure., Conclusions: There is no difference between the blinking metrics of eyelids operated using the frontalis muscle flap advancement technique or frontalis sling with autogenous fascia. The presence of lagophthalmos and keratitis also does not differ between the 2 procedures., Competing Interests: The authors have no financial or conflicts of interest to disclose., (Copyright © 2024 The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc.)

Purpose: To investigate the relationship between the kinematics of spontaneous blinks and the anterior area of the levator palpebrae superioris muscle in patients with Graves orbitopathy (GO)., Methods: This is a case-control study. The authors measured the margin reflex distance of the upper eyelid (margin reflex distance 1), the kinematics of spontaneous blinks, and the anterior area of levator palpebrae superioris muscle in CT coronal scans of patients with Graves upper eyelid retraction (GO) and a control group. The eye with the greatest margin reflex distance 1 was selected for analysis in each group., Results: A total of 68 participants were included, with 36 in the GO group and 32 in the control group. In the GO group, the mean margin reflex distance 1 measured 6.5 mm, while in the control group, it was 3.9 mm. Almost all parameters related to the closing phase of spontaneous blinking activity, including amplitude, velocity, blinking rate, and interblink time, did not differ between the two groups. However, the effectiveness of the blink's amplitude (ratio of blink amplitude to margin reflex distance 1) and the main sequence (relationship between amplitude and velocity) were significantly reduced in the GO group compared with the control group. The area of the levator palpebrae superioris muscle was significantly larger in GO than in controls, with 71.4% of patients' muscles outside of the maximum range of the controls., Conclusions: In patients with GO, there is a reduction in blinking effectiveness, also known as blink lagophthalmos, which is a factor in the common occurrence of ocular surface symptoms. The increase in velocity with amplitude is also reduced in GO., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2023 The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc.)

To assess spontaneous blinking and anomalous eyelid movements in patients with hemifacial spasm with an emphasis on interocular differences. Spontaneous eyelid movements were registered bilaterally for 3 min using a high-speed video camera in 28 patients with hemifacial spasm (HFS) who had not been treated with botulinum toxin injections for at least 5 months. The degree of blink conjugacy, maximum velocity, and amplitude of the closing phase of the blinks were determined for the affected and non-affected sides. Out of the 28 subjects, 23 (82%) presented with abnormal nonconjugate spasms that were similar to blinks, and in 17 (61%), high-frequency eyelid twitches were detected between blinks on the affected eye. The rate of nonconjugate blink-like spasms ranged from 0.3 to 24.7 movements/min. With regard for conjugate blinks, there was no significant interocular difference in amplitudes or eyelid closure velocities. The amplitude and velocity were significantly lower for nonconjugate movements than for spontaneous blinks. HFS is a unique condition in which complex patterns of eyelid movements, including both conjugate and nonconjugate movements, are present. Conjugate movements correspond to spontaneous blinking, and the same metrics were observed in affected and non-affected eyes. Nonconjugate movements correspond to anomalous nonconjugate blink-like spasms and high-frequency eyelid twitches in the affected eye, both of which were characterized by lower amplitudes and velocities than were observed in conjugate movements.

Purpose: To measure the long-term effects of frontalis slings with fascial tissues on the downward eyelid saccadic movements Methods: Downward lid saccades for 10, 20, 30, 40, and 50 degrees of downgaze were measured in a sample of 19 patients with congenital ptosis who underwent frontalis slings with fascia lata (autogenous and banked) and temporalis fascia. Mean postoperative time was 10.7 years ± 3.8 SD. Seventeen age-matched normal subjects comprised the control group. Lid movements as well as the magnitude of brow motion were quantified in all participants with an opto-electronic device that automatically corrected any head movement., Results: Most patients (77.4%) displayed lagophthalmos on eyelid closure. The lid saccades of the patients were severely restricted and did not increase beyond 30 degrees of downgaze. The maximum velocity of lid saccades was also abnormally low. Although the pre- and postoperative lid positions did not differ between eyes operated with the three types of slings, interocular analysis of patients who had bilateral surgery showed that the restrictive effect on the saccadic movements was more asymmetrical with banked fascia than with autogenous tissue. Overall, there was a significant negative correlation between the surgical effect with frontalis contraction and maximum saccadic amplitude. While in controls brow motion accounted for about 3.3-9.3% of the lid saccades, it was responsible for more than 43.5-57.4% lid movements in the patients., Conclusion: Fascial slings have a permanent restrictive effect on the elastic properties of the lids. Postoperative lagophthalmos is a natural consequence of any type of fascial sling. Downward saccadic amplitude is negatively correlated with the surgical effect with frontalis contraction.

Purpose: To measure spontaneous blink metrics and brow motion in patients with congenital ptosis operated with frontalis slings with autogenous fascia lata., Methods: An infrared three-dimensional video motion analyzer was employed to simultaneously measure brow motion and spontaneous blinks of 17 patients with congenital ptosis who underwent frontalis sling with autogenous fascia lata and a control group of equal number of healthy subjects. A customized software identified and quantified the amplitude and maximum velocity spontaneous blinks eyelid and brown motion during a 5-minute observation of a commercial movie. The corneal status of the patients with and without lagophthamos was evaluated with slit-lamp biomicroscopy with fluorescein staining., Results: Lagophthalmos was detected on 13 (76.5%) patients. Out of these 3 (23%) showed signs of inferior superficial keratopathy despite the presence of normal (upwards) Bell's phenomenon in all of them. Blink rate was significantly diminished in the patients. The distribution of interblink time was similar in both groups. The mean amplitude of the down-phase of the patients' blinks was only 38% of the controls. The main sequence slope of the patients' blinks was abnormally low. In controls brow motion was a minute and random event no related to blinks. In the patients, the mean brow amplitude was five times higher than in controls reaching 45% of the blink amplitude., Conclusions: Spontaneous blink amplitude and velocity are severely impaired in patients with fascia lata autogenous slings. After surgery blinking amplitude is linearly related to the amplitude of brow motion.

Purpose: To assess the upper eyelid kinematics during spontaneous blinking in unilateral paralytic lagophthalmos before and after upper eyelid load with gold weight (GW) or autogenous temporalis fascia (TF) sling., Design: Comparative case series., Subjects: Patients with long-standing unresolved unilateral facial palsy who underwent surgical treatment with GW (n = 8) or upper lid cerclage with TF (n = 10). The contralateral eyelid served as the control for each patient (control group)., Methods: Preoperative and postoperative measurements of spontaneous blink kinematics with magnetic search coil and clinical assessment of lid margin position, lagophthalmos and ocular surface exposure, and determine amplitude, maximum velocity and main sequence of spontaneous blinks; relative amplitude of blinks to the pupil center; ocular surface exposure scores; magnitude of lagophthalmos and mid-pupil lid distances., Results: The mean (±SE) down-phase amplitude ratio between paralyzed and contralateral eyelids (blink gain) was 10.0% preoperatively for both groups and significantly increased to 29 ± 6% for the GW group (p < 0.05) and 23 ± 4% for the TF group (p < 0.05). At 6 months the gain was significant for the GW group only (32 ± 7%, p < 0.05). There was no effect on the maximum velocity of the blinks or the main sequence of paretic and contralateral blinks with either surgery. Both procedures lowered the lid margin increasing the number of blinks that reached the pupil center. At 6 months this effect was prominent only for the GW group. Exposure keratopathy scores and lagophthalmos decreased postoperatively especially in the GW group., Conclusions: The beneficial effect of lid load surgeries result from a combination of a small increase on the spontaneous blink amplitude and a static effect due to the reduction of the distance between the lid margin and pupil center.

Purpose: To validate and to report the results of a new inexpensive video-based method to measure upper eyelid motion during spontaneous blinks., Methods: Spontaneous blinks were simultaneously recorded in 21 healthy adult subjects for 5 minutes with magnetic search coil (MSC) and a portable video system (VDS) composed by a commercial high-speed camera coupled to a laptop computer and a blue light-emitting diode. Agreement between the 2 methods was assessed using qualitative comparison of the eyelid motion traces and Bland-Altman plots., Results: The blink traces registered with both methods were virtually identical. With the either method, the relationship between amplitude and maximum velocity was well fitted by linear regression with mean r values = 0.81 (MSC) and 0.85 (VDS). Bland-Altman plots showed good agreement between methods. The mean ± SE differences of amplitude (0.06 ± 0.17 mm) and maximum velocity (5.0 ± 3.4 mm/s) were not significant. With the VDS, it was also possible to quantify the horizontal component of the blink movements. The amplitude of the horizontal shift of the eyelid during blinks was 40% of the vertical downward phase of the movement., Conclusions: Blinking kinematics can be precisely measured using a simple and inexpensive video system suitable for clinical settings.

Purpose: We quantified the main sequence of spontaneous blinks in normal subjects and Graves' disease patients with upper eyelid retraction using a nonlinear and two linear models, and examined the variability of the main sequence estimated with standard linear regression for 10-minute periods of time., Methods: A total of 20 normal subjects and 12 patients had their spontaneous blinking measured with the magnetic search coil technique when watching a video during one hour. The main sequence was estimated with a power-law function, and with standard and trough the origin linear regressions. Repeated measurements ANOVA was used to test the mean sequence stability of 10-minute bins measured with standard linear regression., Results: In 95% of the sample the correlation coefficients of the main sequence ranged from 0.60 to 0.94. Homoscedasticity of the peak velocity was not verified in 20% of the subjects and 25% of the patients. The power-law function provided the best main sequence fitting for subjects and patients. The mean sequence of 10-minute bins measured with standard linear regression did not differ from the one-hour period value. For the entire period of observation and the slope obtained by standard linear regression, the main sequence of the patients was reduced significantly compared to the normal subjects., Conclusions: Standard linear regression is a valid and stable approximation for estimating the main sequence of spontaneous blinking. However, the basic assumptions of the linear regression model should be examined on an individual basis. The maximum velocity of large blinks is slower in Graves' disease patients than in normal subjects.

Spontaneous blinking is essential for maintaining a healthy ocular surface and clarity of vision. The spontaneous blink rate (SBR) is believed to reflect a complex interaction between peripheral influences mediated by the eye surface and the central dopaminergic activity. The SBR is thus extremely variable and dependent on a variety of psychological and medical conditions. Many different methods have been employed to measure the SBR and the upper eyelid kinematics during a blink movement. Each has its own merits and drawbacks, and the choice of a specific method should be tailored to the specific needs of the investigation. Although the sequence of muscle events that leads to a blink has been fully described, knowledge about the neural control of spontaneous blinking activity is not complete. The tear film is dynamically modified between blinks, and abnormalities of the blink rate have an obvious influence on the ocular surface.

Purpose: To determine if the distribution of inter-blink time intervals is constant with repeated measurements with and without topical ocular anesthesia., Methods: Inter-blink time was measured in 15 normal subjects ranging from 19 to 32 years (mean ± SD= 23.9 ± 3.20) with the magnetic search coil technique on 3 different occasions, the last one with topical ocular anesthesia., Results: One-way analysis of variance for repeated measurements showed that topical anesthesia significantly reduced the blink rate (blinks per minute), which was constant in the first two measurements (F=8.27, p=0.0015. First measurement: mean ± SD= 13.7 ± 7.8; second measurement: 13.1 ± 8.5 SD; with topical anesthesia: = 7.2 ± 4.6). However, distributions shape was not affected when the blink rate was reduced. The three distributions followed a Log Normal pattern, which means that the time interval between blinks was symmetrical when the time logarithm was considered., Conclusions: Topical ocular anesthesia reduces the rate of spontaneous blinking, but does not change the distribution of inter-blink time interval.

Purpose: To describe spontaneous blink kinematics in Graves' upper eyelid retraction (UER)., Methods: The magnetic search coil technique was used to record spontaneous blinks of 15 healthy subjects (aged 23-56 years, 15 eyelids) and 15 patients with Graves' UER (aged 22-62 years, 15 eyelids) during a 5-min period of video observation, and the signals were digitized at 200 Hz (12 bits). Overall, a total of 2,798 blinks were recorded for the controls and 1,860 for the patients. The distance between pupil center and upper eyelid margin in the primary position of gaze (MRD) was measured with the Image J software., Results: The blinking rate of patients was lower than that of control subjects, with a mean (+/- SEM) blinking rate (blinks/min) of 13.0 +/- 1.7 for patients and of 20.0 +/- 2.1 for the controls (t = 2.58, P = 0.016). There were no statistically significant differences in blink amplitude between controls (22.7 +/- 3.1 degrees) and Graves' patients (24.7 +/- 3.3 degrees). However, while only 22% of the blinks performed by controls were smaller than MRD, this rate was 78% for patients. In addition, in blinks larger than 25 degrees, patients showed lower down-phase velocity than controls., Conclusions: Patients with Graves' UER show reduced blinks rates and abnormal blink kinematics, which might be related to the development of exposure keratitis in this disease.