Maples Willis C, Hoenes Richard
Southern College of Optometry, Memphis, Tennessee 38104, USA.
Optom Vis Sci. 2007 Mar;84(3):224-8. doi: 10.1097/OPX.0b013e3180339f44.
Convergence insufficiency (CI) is the most prevalent of binocular dysfunctions. A prime finding in the diagnosis of CI is the near point of convergence (NPC).
The NPC was measured six different times on the same 539 children, once in the fall and once in the spring, over the course of 3 years. At each evaluation, the NPC was performed three consecutive times. An accommodative target was used in the testing and the breaks and recoveries were carefully measured and recorded to the nearest centimeter. Normative data for the break and recovery finding were calculated.
We found that the NPC measures receded significantly over three consecutive tests. The recession was not considered clinically significant for either the break or recovery measures. When various break and recovery findings were compared with reported symptoms, it was discovered that one of the break findings statistically predicted the symptomatic group from the asymptomatic group.
The NPC break and recovery does not change appreciably with multiple administrations of the test in the same test period. The criteria for a NPC break score to differentiate the more symptomatic and less symptomatic, elementary school children on the average should be 5 cm, or less. The NPC break and recovery criteria described here should be tentatively used as one of the benchmarks in the diagnosis of convergence insufficiency.
集合不足（CI）是最常见的双眼功能障碍。CI诊断的一个主要发现是集合近点（NPC）。
在3年的时间里，对同一组539名儿童进行了6次NPC测量，秋季和春季各测量一次。每次评估时，连续进行3次NPC测量。测试中使用了调节目标，并仔细测量和记录了分开和恢复的距离，精确到厘米。计算了分开和恢复结果的标准数据。
我们发现，连续3次测试中NPC测量值显著后移。对于分开或恢复测量，这种后移在临床上不被认为具有显著意义。当将各种分开和恢复结果与报告的症状进行比较时，发现其中一个分开结果在统计学上可以将有症状组与无症状组区分开来。
在同一测试期内多次进行测试时，NPC的分开和恢复情况没有明显变化。平均而言，区分症状较多和症状较少的小学生时，NPC分开分数的标准应为5厘米或更小。这里描述的NPC分开和恢复标准应暂时用作集合不足诊断的基准之一。
