目的：探讨近视眼患者正相对调节力(positive relative accommodation，PRA)，负相对调节力(negative relative accommodation，NRA)和PRA/NRA比值的特点及其与等效球镜度数、戴镜年数、戴镜习惯、度数进展情况和瞳孔大小的关系。

方法：回顾性分析2014-08/11在泉州180医院就诊的患者90例90眼。将轻度、中度、高度近视眼和正视眼的PRA， NRA和PRA/NRA比值进行比较。将近视眼患者PRA， NRA和PRA/NRA比值与等效球镜度数、戴镜年数、戴镜习惯、度数进展情况和瞳孔大小进行相关性分析。近视眼进展组和不进展组的PRA，NRA，PRA/NRA比值，、戴镜年数、戴镜习惯、瞳孔大小进行比较。

结果：(1)在年龄、性别和眼压差别无统计学意义的情况下，轻度、中度和高度近视眼和正视眼分别比较， PRA和PRA/NRA比值均较低，NRA均较高；(2)在年龄、性别和眼压差别无统计学意义的情况下，轻度、中度和高度近视组间比较，PRA，PRA/NRA比值和NRA差别均无统计学意义，仅戴镜年数和戴镜习惯差别有统计学意义；(3)戴镜时间越长，PRA和PRA/NRA比值越大、NRA和瞳孔越小。PRA/NRA比值越大、NRA越小，则瞳孔越小；(4)在年龄、屈光度和眼压无差异的条件下，不易进展组戴镜时间长，常戴镜者比率大； 进展组戴镜时间短，不戴和偶戴镜者比率大。

结论：近视眼和正视眼比较，PRA和PRA/NRA比值下降，NRA增大； 但PRA，PRA/NRA比值与近视度数和近视进展无相关性，提示近视发生与发展无法用单一相对调节力改变来解释，而是多因素多机制共同作用的结果。及时准确配镜并坚持配戴可减轻近视眼PRA，PRA/NRA比值下降和减缓近视的进展。

AIM: To research the characteristics of positive relative accommodation(PRA), negative relative accommodation(NRA)and PRA/NRA ratio in myopes. To analyze the relationship among PRA, NRA, PRA/NRA ratio, spherical equivalent degree, years and habbits of wearing glasses, myopia development, and pupil diameter.

METHODS: Aretrospective study of ninety eyes in the 180^th Hospital of Quanzhou from August 2014 to December 2014. PRA, NRA and PRA/NRA ratio were compared among low, moderate, high myopes and emmetropes. The correlation were analyzed among PRA, NRA, PRA/NRA ratio, spherical equivalent degree, years and habbits of wearing glasses, myopia development and pupil diameter. PRA, NRA, PRA/NRA ratio, years and habbits of wearing glasses and pupil diameter were compared between progress group and non-progress group.

RESULTS:(1)Without statistical differences in age, sex and intraocular pressure, PRA and PRA/NRA ratio of myopes were lower than emmetropes, while NRA was higher.(2)Without statistical differences in age, sex and intraocular pressure, PRA, PRA/NRA ratio and NRA had no statistical differences while years and habbits of wearing glasses had statistical differences among low, moderate, high myopes.(3)With longer years of wearing glasses, PRA, PRA/NRA ratio were larger and NRA, pupils were smaller.(4)Without statistical differences in age, diopter and intraocular pressure, one group which were not easy to deepen degree had more often-wear-glasses myopia patiens and longer years of wearing glasses, the other group which were easy to deepen degree had more seldom-wear-glasses myopia patiens and shorter years of wearing glasses.

CONCLUSION: PRA and PRA/NRA ratio of myopes were lower than emmetropes, while NRA was higher. No correlated relation was detected among PRA, NRA, PRA/NRA ratio, spherical equivalent degree and myopia development. It suggests the onset and progress of myopia are related to many factors. Wearing-glass timely and accurately can release the decline of PRA and PRA/NRA ratio and slow down degree development in myopes.

南京军区医学科技创新课题项目(No.08MA084)