[A study on difference of ocular motor parameters in myopia].

Objective: This study sought to assess the difference of these ocular motor parameters in myopia onset and development were explored.
Methods: 31 emmetropia and 46 myopia adult subjects were included in this study. The myopia subjects were divided into three groups as mild myopia, moderate myopia and high myopia. Phoria at distance and near, positive and negative relative accommodation (NRA/PRA) were measured. Accommodative convergence and accommodation stimulus ratio (AC/A) was determined through phoria values' calculation.
Results: Calculated AC/A of myopia was higher than that of emmetropia, and there were trends of elevated AC/A with myopia power increasing. There was significant difference in phoria in near between the myopia group and emmetropia group, but none in that of distance. There was no significant difference in NRA. However, PRA of myopia was lower than that of the emmetropia (P <0.05).
Conclusions: Ocular motor parameters are different in myopia eyes. AC/A is one of key parameters among them, and AC/A is increased in myopia, which indicates out of focus of retinal image in the developing myopia.