Repeatability of ETDRS visual acuity in children.

Area of Science:

• Ophthalmology
• Pediatric Ophthalmology
• Optometry

Background:

• Myopia is a common refractive error in children.
• Accurate measurement of visual acuity (VA) is crucial for monitoring myopia progression and treatment efficacy.
• The Early-Treatment Diabetic Retinopathy Study (ETDRS) log minimum angle of resolution (MAR) chart is a standard tool for VA assessment.

Purpose of the Study:

• To evaluate the repeatability of best-corrected logMAR ETDRS visual acuity measurements in children aged 6 to 11 years with myopia.
• To establish a reliable method for assessing visual acuity changes in pediatric myopia.

Main Methods:

• A subset of 86 children from the Correction of Myopia Evaluation Trial (COMET) with a mean spherical equivalent refractive error of -2.35 D participated.
• Best-corrected monocular visual acuity was measured using ETDRS logMAR charts at baseline and again one month later.
• Participants read letters until they missed all letters on a line, with initial acuity around logMAR 0.4.

Main Results:

• The mean best-corrected logMAR VA showed no significant difference between baseline and 1-month follow-up in either eye.
• Repeatability was not linked to age but showed a slight association with gender in the left eye (boys were ~2 letters more variable).
• The kappa statistic indicated good to excellent agreement (within 1 line) between measurements.

Conclusions:

• A change of no more than +/-0.15 logMAR (approximately +/-8 letters) is considered statistically significant for VA in this pediatric population.
• LogMAR visual acuity measurement is a repeatable and reliable method for assessing acuity in children with myopia.
• The findings are comparable to those reported for adult visual acuity measurements.