Dynamic characteristics of saccadic eye movements are affected by ocular size

Conference Paper

2012

Published in: http://ecvp2012.uniss.it/index.php/eng/Program/Posters-4th-Sept/Eye-movements

Alhazmi, Mohammed . 2012

Purpose: To determine the effect of eye size and ocular rigidity upon the characteristics of saccadic eye movements (SEM). Methods: 33 subjects (mean age 23.52±5.11 years) participated with informed consent. Axial length was measured using partial coherence interferometry (IOLMaster, Carl Zeiss, UK) and ranged from 21.3mm to 27.7mm. Ocular rigidity coefficients were determined using Schiotz tonometry and ranged from 0.013mm-3 to 0.019 mm-3. SEM were stimulated randomly up to 40 degrees right and left, in 10 degree steps using high contrast targets presented upon a widescreen monitor at 40cm viewing distance. Eye movements were recorded continuously at a sampling rate of 60Hz using the Viewpoint video-eyetracker (Arrington Research, USA). Subjects were grouped equally by axial length into short (22.63±0.66mm), medium (24.10±0.41mm) and long (25.90±0.10mm) groups. Results: Axial length was significantly negatively correlated with ocular rigidity (r2=0.78, p<0.001). Peak velocity was significantly faster for the short axial length group (F=20.825, df=2,263, p<0.001), although initial SEM accuracy was significantly worse (F=2.954 df=2,263 p=0.048). Peak velocity was significantly greater with increasing stimulus magnitude (F=741.759, df=3,263, p<0.001) and was also significantly greater for abductive movements (F=3.940 df=1,263 p=0.048). Conclusion: Eyes with short axial length and higher ocular rigidity generate significantly higher velocities of SEM.

• Publication Work Type: Conference Poster
• Conference Name: European Conference on Visual Perception (ECVP).
• Sponsoring Organization: European Conference on Visual Perception