Stereopsis after congenital cataract.
OBJECTIVE
The authors determined whether stereopsis can be demonstrated in children treated for congenital cataract after compensating for their amblyopia and strabismus.


METHODS
A custom-made set of large stereograms was used to compensate for amblyopia and presented in a synoptophore to facilitate motor fusion. Each pair of stereograms contained five wide vertical bars of high contrast, of which two or three were in crossed disparity. The authors aligned the stimuli in the synoptophore, then decreased the disparity until the child could no longer identify which bars appeared to be "in front."


RESULTS
In normal children (n = 25), stereo acuity on this test (Tytla-Lewis-Maurer-Brent [TLMB] test) correlated well with the Titmus and Randot results within the ranges measured by those tests. Seven children in whom a traumatic cataract had developed after 6 yr of age (four with no clinical stereopsis) had TLMB test stereo acuities ranging from 225 to 28 arc-sec. Of 30 children treated for congenital cataract with no clinical stereopsis, 5 regularly achieved a TLMB stereo acuity of up to 225 arc-sec, and 2 with Titmus stereo acuities up to 200 arc-sec, each had a TLMB stereo acuity of 112 arc-sec. These seven congenital cases (two unilateral and five bilateral) with measurable TLMB acuities are among those with the shortest deprivation, the highest minimum resolvable acuity, and the highest contrast sensitivity.


CONCLUSIONS
By compensating for amblyopia and strabismus, stereopsis can be demonstrated in some form-deprived amblyopic patients.
Tytla
M E
ME
Department of Ophthalmology, Hospital for Sick Children Toronto, Ontario, Canada.
Lewis
T L
TL
Maurer
D
D
Brent
H P
HP
D000293:Adolescent; D000550:Amblyopia / Q000628:therapy; D002386:Cataract / Q000151:congenital* / Q000209:etiology / Q000503:physiopathology*; D002387:Cataract Extraction; D002648:Child; D002675:Child, Preschool; D003867:Depth Perception / Q000502:physiology*; D005131:Eye Injuries / Q000150:complications; D006801:Humans; D007908:Lens, Crystalline / Q000293:injuries; D012683:Sensory Deprivation; D013285:Strabismus / Q000628:therapy; D014792:Visual Acuity