PURPOSE: To assess quality and cut-off point (VA <0.7) of the examinations performed by teachers to detect reduced visual acuity (VA) in schoolchildren participants of the project called "Eye in eye " in Marilia-SP, Brazil. METHODS: Visual acuity measurements were performed by trained teachers using Snellen's chart. The children with VA <0.7 in one of the eyes were referred to an ophthalmic examination. The ophthalmic examination was considered gold standard to assess quality and cut-off point of the examinations performed by teachers. VA test was performed in 604 schoolchildren of state public schools (1,208 eyes). Analyses were based on examined eyes. We calculated sensitivity (S), specificity (E), positive predictive value (PPV), negative predictive value (NPV) and likelihood rate (LR). We compared the means obtained by the teachers' examinations to means of the ophthalmologist's examinations. ROC curve was produced to evaluate whether VA lower than 0.7 is the best value for referral to an ophthalmic examination. RESULTS: VA means obtained by teachers and ophthalmologic examinations were 0.70 ± 0.16 and 0.88 ± 0.2 respectively. The difference between teachers' and ophthalmologists' examinations was 0.18 (p<0.0001). S, E, PPV, NPV e LR were: 82%, 40%, 27%, 89% and 1.37, respectively. False positive and negative rates were 59.5% and 18%. ROC curve evidenced that visual acuity of 0.7 was the best cut-off point to refer schoolchildren to an ophthalmic exam. CONCLUSIONS: We demonstrated the importance of the teachers' participation in improved schoolchildren ocular health. The examination performed by teachers obtained a satisfactory S with low E, NPV and high values of false positive results. The best cut-off point to refer schoolchildren to an ophthalmic examination was VA of 0.7.
Visual acuity; School health; Sensitivity and specificity; Child
