Abstract
Purpose: :
To compare a new preferential looking test with square patterns to the reference Teller acuity card test with lines patterns.
Methods: :
We evaluated binocular and monocular grating acuity in 8 patients (range 3 months-old to 18 months-old) without ocular disorders or refraction anomaly. The infants were tested alternatively with Teller visual acuity cards and new square patterns acuity cards. One side of the card has the square pattern and alle the card is grey. When putting the card at a long distance no difference appears with the two sides. The cards were presented to the infants at 80 cm. The new tested patterns were in cycle/degree (0.32, 0.64, 1.3, 4.8, and 9.8 c/cm) . Assessments were made with the two different acuity card tests by one single observer, blind to the pattern presented.
Results: :
All the infants completed the two testings in binocular conditions in an average time of 10 minutes. One child failed for the second monocular acuity by failure of attention. With Teller acuity cards assessment of the cards was from 3.5 to 4.5 c/cm and with the square patterns assessment was 4.8 to 9.8 c/cm with a correspondance of the two tests. In binocular of the 8 infants, 4 assessed the Teller 3.5 c/cm card corresponding to 3 with the square 4.8 c/cm card and 1 with the square 9.8 c/cm card. Of the 8 infants, 4 assessed the Teller 4.5 c/cm card corresponding to 4 with the square 9.8 c/cm card. The square patterns appear reliable but easier of one scale for testing infants. These patterns are similar to VEP testing.
Conclusions: :
Preferential looking procedures are efficient testing for evaluation of infant acuity. A larger study will give more information for the corresponding patterns with Snellen equivalent acuity. The new square pattern test gives reliable comparative evaluation of visual acuity in infants. The square acuity card test can be useful in clinical practice for children with ocular disorders.
Keywords: visual development: infancy and childhood • pattern vision • visual acuity