To study the pupillary centroid shift of myopia and characteristics of pupil diameter change from scotopic to photopic condition.

A case series study was carried out, 140 eyes of 70 myopia patients from September to November 2016 in Tianjin Eye Hospital were enrolled.The pupillary centroid shift and pupil diameter parameters were measured by visual quality analyzer from scotopic (0.017 lx) to photopic (10.400 lx) condition.This study followed the Declaration of Helsinki.

Under the scotopic and photopic conditions, the pupil diameter was positively correlated between the bilateral eyes (scotopic: r_s=0.85, P<0.001; photopic: r=0.85, P<0.001), and the pupil diameter variation from scotopic to photopic condition was positively correlated between the bilateral eyes (r=0.75, P<0.001). The pupil diameter in scotopic and photopic conditions, and the change of pupil diameter in the right eyes were significantly higher than those in the left eyes (all at P<0.05). The pupillary centroid shift was within 0.2 mm in the left eyes of 94.2% (66/70) subjects and in the right eyes of 97.1%(68/70) subjects.The pupillary centroid shift of all subjects was within 0.3 mm.From scotopic to photopic condition, the pupil centroid was mainly shift to the nasal superior direction.There was no significant correlation between pupil diameter and age or gender.There was no significant correlation between pupillary centroid shift and age, diopter or pupil diameter.

The binocular pupillary centroid shift are symmetrical from scotopic to photopic condition in myopic eyes, and the pupil centroid mainly shift to nasal superior direction.

Myopia; Pupil; Scotopic; Photopic; Illumination