Biomedical subjects

E Schanel-Klitsch

Publications and source records attributed to E Schanel-Klitsch.

4 recordsLinked to original sources

PubMed1996

Stereoacuity development: 6 months to 5 years. A new tool for testing and screening.

A new tool to measure changes in random dot stereoacuity development from 6 months to 5 years of age was developed and tested. Either a forced choice or operant preferential looking (PL) paradigm with a happy face target was successfully used to test 136 children. Results indicate that stereoacuity measurements continue to develop through the first years of life. Although children below 24 months of age can be expected to have stereo thresholds in the range of 300 sec arc, there is a transition at approximately 24 months of age after which stereoacuity approaches adult levels. The sensitivity of this test in detecting binocular vision problems was 80%. These results provide guidelines for the assessment of stereoacuity in young children and also provide a new tool for the early detection of binocular vision anomalies.

Child Development↗

PubMed1991

Stereoacuity development in young children.

An operant preferential looking (OPL) test with random dot stereo targets was used to gather developmental data on stereoacuity thresholds in 180 children between 18 and 65 months of age. Results indicated a steady improvement in stereoacuity with age from 250 sec arc in the youngest children tested to 60 sec arc in the oldest group of children. The greatest improvement in stereoacuity occurs at 30 months of age where mean values improve from 225 to 125 sec arc. This large change in stereo threshold appears to be attributable to the significantly higher variability in responses in the children under 30 months of age vs. the lower variability in responses in children over 30 months of age. The overall steady improvements in stereoacuity appear to be a result of the developmental changes in the variability of responses rather than actual neurophysiological changes within the visual system.

Age Factors↗

PubMed1989

Stereopsis testing in 18- to 35-month-old children using operant preferential looking.

Forced choice operant preferential looking (OPL) was used to evaluate stereopsis in children between 18 and 35 months of age. Eighty-three children who passed a vision screening were tested with a ring-shaped random dot target that stood out in depth. Food was used to reinforce looking at the target. Children were also administered the Random Dot E (RDE) as a comparison measure. Four children were unable to complete testing with OPL compared with 31 who were unable to complete testing with the RDE. This difference was most apparent in children under 24 months of age. This new procedure appears to be a useful technique to evaluate stereopsis in very young children.

Child, Preschool↗

PubMed1985

Sensitivity of the human neonate to short- and long-wavelength stimuli.

Increment thresholds for long- and short-wavelength stimuli were determined under both white and orange adaptation. The forced-choice preferential looking technique (FPL) was used to test neonates shortly after birth and again at 2 months postnatal. Results were compared to an adult control group. Neonates, 2-month-olds, and adults showed a change in relative sensitivity to the 617 and 453 nm test stimuli with a change in chromatic adaptation, indicating the existence of at least 2 separately adaptable chromatic mechanisms at birth. These results are tentatively discussed in terms of the functioning of rods and short-, middle- and long-wavelength cones. A decrease in all thresholds with age is discussed with regard to attentional differences and postnatal neural development in the visual system.

Adaptation, Ocular↗