An assessment of the pattern of spontaneous eyeblink activity under the influence of topical ocular anaesthesia.
OBJECTIVE
To determine whether there is a change in the pattern of human eyeblink events under topical ocular anaesthesia.


METHODS
Forty male subjects, aged between 19 and 52 years and with no significant ocular surface disease, were recruited. Their spontaneous eyeblink activity, in primary eye gaze position and in silence, was recorded for 5-min periods, before and after instillation of benoxinate 0.4% eyedrops. The surface anaesthesia was confirmed by aesthesiometry.


RESULTS
The spontaneous eyeblink rate (SEBR) decreased from 9.1+/-4.0 blinks/min to an average of 5.7+/-3.3 blinks/min, with 37 subjects showing a decreased eyeblink rate under anaesthesia. Three blink patterns were observed before anaesthesia (symmetrical, J-type and I-type) and these were essentially unchanged under anaesthesia.


CONCLUSIONS
These studies confirm that the SEBR is usually reduced under surface anaesthesia (so is sensitive to exogenous control) but the pattern of the eyeblink activity is unchanged (so is less sensitive to exogenous control). The removal of exogenous stimuli by anaesthesia does not shift the eyeblink pattern to a single type, so indicates endogenous control.
Naase
Taher
T
Department of Vision Sciences, Glasgow-Caledonian University, Glasgow, G4 OBA, UK.
Doughty
Michael J
MJ
Button
Norman F
NF
D000328:Adult; D000772:Anesthesia, Local; D000779:Anesthetics, Local / Q000008:administration & dosage*; D001767:Blinking / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011343:Procaine / Q000008:administration & dosage* / Q000031:analogs & derivatives*; D013997:Time Factors; D014741:Video Recording
D000779:Anesthetics, Local; D011343:Procaine; C005298:benoxinate