Diurnal Tracking of Blink and Relationship to Signs and Symptoms of Dry Eye.
OBJECTIVE
To assess diurnal changes in the signs and symptoms of dry eyes and their relationship to diurnal interblink interval (IBI) in normal subjects and in subjects with dry eye.


METHODS
Blink data were collected from 9:00 AM to 8:00 PM during 2 days of normal activity using an electrocardiogram monitoring device. All subjects recorded ocular discomfort (0-5 scale) and primary activity hourly each day in a diary. Inferior and central fluorescein staining was graded by slit lamp (0-4) at the start and end of each day. Blink activity was detected using an algorithm based on recognition of the waveform corresponding to the kinematic properties of the blink signal.


RESULTS
Normal subjects (N = 12) reported negligible symptoms, and results did not show a diurnal change in group hourly IBI. Mean daily IBI for the group with dry eye (N = 15) (4.63 ± 1.63 s) was shorter than that for the normal group (5.28 ± 1.48 s) (P = 0.0483). Correlation of diurnal symptoms and mean hourly IBI was relatively weak (r = -0.248). A repeated-measures model found IBI to be significantly associated with the time of day (P = 0.0028). Inferior corneal staining showed a small but significant diurnal increase for both normal group and group with dry eyes.


CONCLUSIONS
Diurnal blink tracking reveals significant trending with symptoms. Diurnal change in IBI may be an appropriate surrogate for symptoms in the study of dry eye.
*Ora, Inc., Andover, MA; †SDC, Inc., Tempe, AZ; and ‡Department of Ophthalmology, Harvard Medical School, Boston, MA.
John D
JD
Rodriguez
Keith J
KJ
Lane
George W
GW
Ousler
Endri
E
Angjeli
Lisa M
LM
Smith
Kirk M
KM
Bateman
Mark B
MB
Abelson
D000465:Algorithms; D001767:Blinking / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D015352:Dry Eye Syndromes / Q000175:diagnosis* / Q000503:physiopathology*; D004576:Electromyography; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D009799:Ocular Physiological Phenomena