Abstract
Purpose:
The usefulness of diagnostic tests for microesotropia is stil a mismatching problem. We have examined the most common and used test to detect microesotropia in daily practice: Lang I stereo-test. The aim of our study was to analyze statistically this test to detect its real effectiveness in children.
Methods:
We considered 313 patients whose age ranged from 3 to 18 years (mean age 7.5) suspected to be microesotropic. Children younger than 3 years of age were excluded from the study since it was not possible to detect any answer from the Lang 1 stereo-test due to the early age. All underwent a full orthoptic and ophthalmological examination. The stereo-test was presented at a distance of 40-50 cm. “Paliaga 8 diopters base- in test” was considered the “gold standard” diagnostic test.
Results:
Among all the patients, 282 ( 90,1%) were considered normal (without strabismus) and 31 (9,90%) were considered affected (with strabismus). The authors found a specificity of 99% and a sensitivity of 87%. We could also calculate the positive predictive value (90%) and the negative predictive value (91%) of the test since we knew the prevalence of microesotropia in our population. Likelihood ratio was detected to evaluate the efficacy of the test in daily practice and it corresponds to 87,10.
Conclusions:
Lang I stereo-test is a simple test with high specificity and good sensitivity. Positive and negative predictive values correspond to a test with a good reliability in young children. Likelihood ratio stresses the importance of Lang I stereo test in diagnosing microesotropia in children elder than 3 years of age. Infact the problem we encountered in our practice was the cooperation of young patients, since we were obliged to exclude in our statistical analysis children younger than three years due to the impossibility to register reliable data. We stress the importance to involve children aged more than three to have a good reliability of this test in practice to detect microesotropic patients. Younger children don’t allow to collect answers to make the correct diagnosis and should be monitored with other tests with good statistical evaluation according to age.
Keywords: 515 esotropia and exotropia •
524 eye movements: recording techniques •
556 infant vision