The Parsons visual acuity test for screening children 18 to 48 months old

Area of Science:

• Ophthalmology
• Pediatric Medicine
• Vision Science

Background:

• Assessing visual acuity in young children and difficult-to-test populations presents significant challenges.
• Standard visual acuity tests are often not suitable for pre-verbal or uncooperative individuals.
• Accurate visual assessment is crucial for early detection of visual impairments.

Purpose of the Study:

• To evaluate the efficacy of the Parsons visual acuity test (PVAT) in obtaining visual acuity thresholds.
• To determine the success rate of PVAT in different age groups of young children.
• To assess the accuracy of PVAT referral criteria.

Main Methods:

• The Parsons visual acuity test (PVAT), utilizing modified Allen test targets, was administered.
• Visual acuity thresholds were obtained in children aged 18-36 months.
• Referral decisions were made based on PVAT criteria and compared to a gold standard.

Main Results:

• A visual acuity threshold was successfully obtained in 44% of 18- to 24-month-olds and 90% of 25- to 36-month-olds.
• The most common visual acuity (mode) across all ages tested was 20/30.
• The PVAT referral criterion correctly identified the need for referral 83% of the time.

Conclusions:

• The Parsons visual acuity test (PVAT) is a valuable tool for assessing visual acuity in young children.
• PVAT demonstrates increasing success rates with age, particularly in the 25-36 month range.
• The PVAT referral criterion shows good accuracy in guiding decisions for further ophthalmological evaluation.