Lang I stereotest: reliability and accuracy for amblyopia diagnosis

Key words: Amblyopia, Lang Stereotest I, Sensibility, Specificity

Background - Amblyopia is a complex anomaly of vision development in first years of life, that causes unilateral or bilateral visual acuity defect and it represents a serious socio-economic barrier in the modern society.
Objectives - To evaluate the reliability of Lang I Stereotest, one of the most used diagnostic tool by orthoptists, ophthalmologists and pediatricians, because an early detection is basic for satisfactory functional recovery.
Materials and methods A retrospective observational study was carried out on 236 subjects of 3-8 years old, selected with specific inclusion/exclusion criteria as part of a larger outpatient population (n = 380). For each of them, we focused on the presence/absence of amblyopia and the outcome of Lang I. We computed sensitivity, specificity and predictive values, in addition to compare if the test results could be related to children’s age.
Results - Amblyopia was detected in 44% of children. Sensitivity was low (54%), with acceptable specificity (88%). There are no statistically significant relationships between outcome and children’s age (p = 0.560).
Conclusion - Lang Stereotest I performances is not accurate enough when used in a high-prevalence referral setting as a stand-alone screening test for amblyopia diagnosis. Given its acceptable specificity, test-positive children should be referred to ophthalmic specialists regardless of their age.