Sensitivity and specificity of visual acuity screening for refractive errors in school children

Area of Science:

• Ophthalmology
• Pediatric Optometry
• Public Health Screening

Background:

• Refractive errors are a significant cause of visual impairment in children.
• Early detection and intervention are crucial for preventing long-term vision problems.
• Accurate and efficient screening tools are needed for school-aged populations.

Purpose of the Study:

• To determine the optimal visual acuity cutoff point for screening schoolchildren for refractive errors.
• To evaluate the efficacy of the modified Early Treatment Diabetic Retinopathy Study (ETDRS) chart for this purpose.

Main Methods:

• Visual acuity testing using modified ETDRS charts was conducted on 1,028 schoolchildren aged 7-9 years.
• Cycloplegic autorefraction was performed to diagnose myopia, hyperopia, and astigmatism.
• Sensitivity, specificity, and predictive values were calculated for various visual acuity referral criteria.

Main Results:

• A referral criterion of visual acuity worse than or equal to 0.28 logarithm of the minimum angle of resolution yielded a satisfactory sensitivity/specificity profile.
• The screening test achieved 72% sensitivity and 97% specificity.
• Positive and negative predictive values were 96% and 78%, respectively.

Conclusions:

• The modified ETDRS visual acuity chart is a sensitive and specific tool for screening refractive errors in schoolchildren.
• A referral criterion of visual acuity ≤0.28 logarithm of the minimum angle of resolution is recommended for this screening process.
• This approach can aid in the early identification of vision problems in pediatric populations.