Assessing the Accuracy and Feasibility of a Refractive Error Screening Program Conducted by School Teachers in Pre-Primary and Primary Schools in Thailand

<div><p>Introduction</p><p>As part of the development of a system for the screening of refractive error in Thai children, this study describes the accuracy and feasibility of establishing a program conducted by teachers.</p><p>Objective</p><p>To assess the accuracy and feasibility of screening by teachers.</p><p>Methods</p><p>A cross-sectional descriptive and analytical study was conducted in 17 schools in four provinces representing four geographic regions in Thailand. A two-staged cluster sampling was employed to compare the detection rate of refractive error among eligible students between trained teachers and health professionals. Serial focus group discussions were held for teachers and parents in order to understand their attitude towards refractive error screening at schools and the potential success factors and barriers.</p><p>Results</p><p>The detection rate of refractive error screening by teachers among pre-primary school children is relatively low (21%) for mild visual impairment but higher for moderate visual impairment (44%). The detection rate for primary school children is high for both levels of visual impairment (52% for mild and 74% for moderate). The focus group discussions reveal that both teachers and parents would benefit from further education regarding refractive errors and that the vast majority of teachers are willing to conduct a school-based screening program.</p><p>Conclusion</p><p>Refractive error screening by health professionals in pre-primary and primary school children is not currently implemented in Thailand due to resource limitations. However, evidence suggests that a refractive error screening program conducted in schools by teachers in the country is reasonable and feasible because the detection and treatment of refractive error in very young generations is important and the screening program can be implemented and conducted with relatively low costs.</p></div

Mutations in the NDP gene: contribution to Norrie disease, familial exudative vitreoretinopathy and retinopathy of prematurity

Background: To examine the contribution of mutations within the Norrie disease (NDP) gene to the clinically similar retinal diseases Norrie disease, X-linked familial exudative vitreoretinopathy (FEVR), Coat's disease and retinopathy of prematurity (ROP). Methods: A dataset comprising 13 Norrie-FEVR, one Coat's disease, 31 ROP patients and 90 ex-premature babies of <32 weeks' gestation underwent an ophthalmologic examination and were screened for mutations within the NDP gene by direct DNA sequencing, denaturing high-performance liquid chromatography or gel electrophoresis. Controls were only screened using denaturing high-performance liquid chromatography and gel electrophoresis. Confirmation of mutations identified was obtained by DNA sequencing. Results: Evidence for two novel mutations in the NDP gene was presented: Leu103Val in one FEVR patient and His43Arg in monozygotic twin Norrie disease patients. Furthermore, a previously described 14-bp deletion located in the 5' unstranslated region of the NDP gene was detected in three cases of regressed ROP. A second heterozygotic 14-bp deletion was detected in an unaffected ex-premature girl. Only two of the 13 Norrie-FEVR index cases had the full features of Norrie disease with deafness and mental retardation. Conclusion: Two novel mutations within the coding region of the NDP gene were found, one associated with a severe disease phenotypes of Norrie disease and the other with FEVR. A deletion within the non-coding region was associated with only mild-regressed ROP, despite the presence of low birthweight, prematurity and exposure to oxygen. In full-term children with retinal detachment only 15% appear to have the full features of Norrie disease and this is important for counselling parents on the possible long-term outcome

Detection rate of the teachers according to the severity of visual acuity level.

<p>Mild or no visual impairment: PVA equal to or better than 20/70; moderate visual impairment: PVA worse than 20/70 - equal to or better than 20/200; severe visual impairment to blindness: PVA worse than 20/200.</p

Age, gender, and number of students screened by each teacher.

<p>Age, gender, and number of students screened by each teacher.</p

Defining the best cut-off point for pre-primary school teachers' screening and estimated cases for a nationwide program.

<p><i>* Hypothetical situation for 1,591,704 pre-primary school students </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0096684#pone.0096684-2" target="_blank">[<i>28</i>]</a><i>; children receiving spectacles are the children who have significant refractive error.</i></p

Sensitivity and specificity value of the teachers with various levels of gold standards.

<p>Sensitivity and specificity value of the teachers with various levels of gold standards.</p