Age dependent normative data of vertical and horizontal reflexive saccades

Purpose There is some controversy whether or not saccades change with age. This cross-sectional study aims to clarify the characteristics of reflexive saccades at various ages to establish a normative cohort in a standardized set-up. Second objective is to investigate the feasibility of saccadometry in daily ophthalmological practice. Methods One hundred healthy participants aged between 6 and 76 years underwent an ophthalmologic examination and saccadometry, using an infrared video-oculography device, sampling at 220 Hz. The reflexive saccades were evoked in four directions and three target displacements each (5 degrees/15 degrees/30 degrees horizontally and of 5 degrees/10 degrees/20 degrees vertically). Saccadic peak velocity, gain (amplitude/ target displacement) and latency were measured. Results Mean peak velocity of saccades was 213 degrees/s (+/- 29 degrees/s), 352 degrees/s (+/- 50 degrees/s) and 455 degrees/s (+/- 67 degrees/s) to a target position 5 degrees, 15 degrees and 30 degrees horizontally, respectively, and 208 degrees/s (+/- 36 degrees/s), 303 degrees/s (+/- 50 degrees/s) and 39 degrees/s (+/- 71 degrees/s) to a target position 5 degrees, 10 degrees and 20 degrees vertically. The association between peak velocity and eccentricity proved to be present at any age in all four directions. We found no relevant effect of age on peak velocity, gain and latency in a fitted linear mixed model. However, latency becomes shorter during childhood and adolescence, while in adulthood it is relatively stable with a slight trend to increase in the elderly. Saccades are more precise when the target displacement is small. Isometric saccades are most common, followed by hypometric ones. All children and elderly were able to perform good quality saccadometry in a recording time of approximately 10 minutes. Conclusion The presented data may serve as normative control for further studies using such a videooculography device for saccadometry. The means of peak velocity and the gain can be used independently from age respecting the target displacement. Latency is susceptible to age.