Screening for amblyopia and strabismus with the Lang II stereo card

. Purpose:
To evaluate the effectiveness of the Lang II stereo card as a screening test for amblyopia and/or strabismus. Methods:
A total of 1046 children aged 12-13 years were examined in a field study in the Göteborg area, Sweden. In addition to the Lang II stereo card, the examination included visual acuity, cover testing, cycloplegic refraction, and inspection of the optical media and posterior pole. Results:
If every incorrect subject response was considered a reason for referral, the Lang II test would have correctly identified 82% (23 subjects) of the 28 children with manifest strabismus and 38% (11 subjects) of the 29 children with amblyopia. The test failed to refer 45% (21 subjects). Of all subjects referred, 44 (63%) were found to be ophthalmologically normal. Conclusions:
The Lang II stereo card is neither a reliable nor an efficient method of screening for amblyopia and/or strabismus.