Murdoch I, Jones B R, Babalola O E, Cousens S N, Bolarin I, Abiose A
Ahmadu Bello University Teaching Hospital, Kaduna, Nigeria.
Bull World Health Organ. 1996;74(6):573-6.
A new screening test for optic nerve pathology is described, consisting of a series of four red targets presented at an angle of 12 degrees in the paracentral field above and below the horizontal meridian. Nonperception and desaturation of the targets are recorded. Inter-observer variability studies found a kappa value = 0.8. A total of 6831 individuals aged > or = 5 years in communities that were mesoendemic for savanna onchocerciasis in Kaduna State, northern Nigeria, were screened using the test. Of the participants 22% were unable to complete the test; almost two-thirds of these (62%) were aged 5-8 years. After exclusion of those visually impaired or blind according to WHO criteria and those unable to complete the test, the test showed a sensitivity of 40% and a specificity of 98% for optic nerve disease when inability to visualize one or more targets was used as the definition of test failure. The sensitivity increased to 54% with a specificity of 96% when the criterion for failure included desaturation of one or more targets. These values compare favourably with those for other available screening methods. The test took 1-2 minutes to perform and was readily accepted by patients and nurses.
本文描述了一种用于视神经病变的新型筛查测试，该测试由在水平子午线上下旁中心视野以12度角呈现的一系列四个红色目标组成。记录目标的未感知和饱和度降低情况。观察者间变异性研究发现kappa值 = 0.8。使用该测试对尼日利亚北部卡杜纳州热带草原盘尾丝虫病中度流行社区中6831名年龄≥5岁的个体进行了筛查。22%的参与者无法完成测试；其中近三分之二（62%）年龄在5 - 8岁。根据世界卫生组织标准排除视力受损或失明者以及无法完成测试者后，当将无法看到一个或多个目标作为测试失败的定义时，该测试对视神经疾病的敏感性为40%，特异性为98%。当失败标准包括一个或多个目标的饱和度降低时，敏感性提高到54%，特异性为96%。这些值优于其他现有筛查方法的值。该测试执行时间为1 - 2分钟，患者和护士都很容易接受。
