A comparison of Wright card with Teller card for detection of amblyopia.

PURPOSE

Teller acuity cards are used to assess visual acuity in infants but can underestimate amblyopia. In order to improve amblyopia detection, a new luminance balanced checkered card of 4.8 cycles/cm frequency was developed by Wright and Vistech (Dayton, Ohio). The Wright card was compared with a corresponding Teller card (of 4.8 cycles/cm) for detection of amblyopia.

METHODS

A prospective masked study of 44 children was carried out. Each was assessed for amblyopia using both the Wright and Teller cards in addition to the Snellen or Allen card (optotype). The results were analyzed statistically using repeated measures of ordinal data.

RESULTS

Thirteen eyes were found to be amblyopic with optotype testing, two with the Teller card and 17 with the Wright card. With optotype acuity as the standard, the sensitivity and specificity of the Teller card was 15.3% and 100%, while that of the Wright card was 100% and 94.6%.

DISCUSSION

The Teller card is associated with high false negative test rate because it assesses grating acuity and allows spurious resolution possibly due to an edge artifact. This artifact is less pronounced with the Wright card. Further, the stripes on the Teller card require resolution only in horizontal axis, while the checkers requires uniform resolution in all axes. Different pathways for neural processing may also contribute to the disparate results with these methods.

CONCLUSIONS

The Wright card was more sensitive than the Teller card for the detection of amblyopia in this study population and has potential value in preverbal children.