Serial measurements of higher-order aberrations after blinking in normal subjects

PURPOSE. To investigate sequential changes in the optical quality of normal eyes associated with blinking. METHODS. Ocular higher-order aberrations (HOAs) were measured sequentially by using a wavefront sensor for 30 seconds in 20 eyes of 20 normal subjects. During the measurement, subjects were forced to blink every 10 seconds. The obtained aberration data were analyzed in the central 4-mm diameter for coma-like, spherical-like, and total HOAs up to the sixth-order Zernike polynomials. RESULTS. The serial changes in the HOAs with blinking were classified into four groups by pattern: stable (25%), small-fluctuation (45%), sawtooth (20%), and others (10%). In the subjects with the sawtooth pattern, the total HOAs increased significantly (P < 0.001, one-way repeated-measures ANOVA) with time between blinks. Increased total HOAs and coma-like aberrations in the subjects with the sawtooth pattern suggested that the inferosuperior asymmetric change in tear film thickness is responsible. CONCLUSIONS. Dynamic changes in HOAs after blinking showed variations even in clinically normal subjects. Serial measurements of HOAs may be useful in evaluating the dynamic changes in tear film and the effects on the quality of vision after blinking.