Neha Tyagi
Assistant Professor, Department of Ophthalmology, ICARE Institute of Medical Sciences and Research & Dr. Bidhan Chandra Roy Hospital, Haldia
Abstract
BACKGROUND: Preschool vision screening (PVS) has been recommended as a cost-effective method to differentiate children with vision impairments. The primary aim of vision screening children at preschool is to reduce the prevalence of amblyopia by referring them while the condition is still amenable to treatment. If the visual deficit is not corrected during the period of visual development, it is likely to be permanent and cannot be rectified later. It is estimated that 5% to 6% of all preschool children have some form of vision defect that might require treatment or follow up, emphasizing the need for preschool vision screening and comprehensive eye care.
OBJECTIVE: To develop a protocol for screening visual impairment in preschool children aged 3 to 5 years
MATERIAL AND METHOD: The permission for conducting the study was obtained from the Institutional Research Committee. Subsequently, the permission was obtained from the Head of the Department for carrying out the study in the Outpatient Department of Ophthalmology. The screening tests had to be validated, and visual acuity measurement was the most used test across nations. Hence, the sample size calculation was determined using the formula 4pq/d2 /prevalence where “p” was the sensitivity of visual acuity chart and “d” was the precision level. Any validated tool must have at least 70% sensitivity.
RESULT: Titmus stereo fly test had high sensitivity but poor specificity. Frisby and Randot preschool had good sensitivity and moderate specificity to screen vision impairment. AUC was moderate. Stereo acuity charts were good screening but moderate diagnostic tools. Plusoptix A09 had moderate sensitivity and specificity for spherical and cylindrical refractive errors compared to vision and stereo charts AUC was also poor. Plusoptix A09 showed better sensitivity for cylindrical values.
CONCLUSION: The stereo acuity charts exhibited good sensitivity and moderate specificity making them good screening but moderate diagnostic tools. Plusoptix A09 had moderate sensitivity and specificity for visual impairment screening compared to visual acuity and stereo charts. Good agreement was observed between Lea and HOTV, Lea and E and HOTV and E vision charts.
KEYWORDS: Preschool vision screening, Visual impairment, Positive Predictive value, Plusopitix A09 and Visual acuity charts