Objective To observe the relationship between position of normal central fixation and the position of the optic disc, and to find out the features of stability of fixation. Methods The position of central fixation of 120 eyes of 60 healthy adults was determined by MP-1 microperimeter. The position of central fixation relative to the position of the optic disk was measured. The relationship between the central fixation and the age or refraction was analyzed statistically. The difference between the right and left eye in each individual was analyzed with t test. Results The central fixation located at the retina with the horizontal distance of 14.48deg;plusmn;1.85deg; and vertical distance of －2.14deg;plusmn;1.26deg; from the temporal edge of the optic disk. In the 120 eyes, 90% of the central fixation located in a bivariate normal ellipse. The normal eyes usually kept in a slightly moving condition when a normal person fixing on a subject. The median of horizontal and vertical deviation was 0.4deg; and 0.3deg; respectively. Conclusion The distribution of central fixation in healthy adults is a bivariate normal ellipse. When fixing on a subject, the moving extent of the eyes in the horizontal direction is larger than that in the vertical direction.
ObjectiveTo identify the clinical significance of epileptic eye movement for localization of posterior epileptic seizures. MethodsThere were 12 posterior epileptic patients, who were undertaken the detailed presurgical evaluation and ictal SEEG recording, and the epileptogenic zone of whom was confirmed restricted within posterior cortex through the boarder of epileptic cortical resection and the result of epileptic surgery, included in the research. ResultsThe cluster analysis of posterior cortical area of interest showed that parieto-occipital sulcus (POS) with the adjacent cortical areas belonged to the Medial Group; intraparietal sulcus (IPS) with the adjacent areas belonged to the Intermediate Group; and the Lateral Group included anterior occipital sulcus (AOS) and posterior temporal cortex. Eyes forced stare had the significant correlation with IPS, POS and related cortical group. Contraversive eye deviation had no significant correlation with cortical eye field with the related cortical areas. ConclusionsForced eye stare was significant eye movement in posterior epilepsy, and had significant correlation with IPS and POS. Ipsiversive eye deviation and convergence binocular movement were rare semiology in posterior epilepsy, and AOS had significant correlation with the two type of epileptic eyes movement.