Abstract
Purpose: :
The purpose of this study was to compare the amount of time needed to complete either test of stereopsis in a screening setting for persons with intellectual or developmental disability.
Methods: :
One hundred twenty subjects from the Chicago Public School participated in the Special Olympics Lions Clubs International Opening Eyes (SOLCIOE) vision screening. Stereopsis testing with the Random Dot E (RDE) test is a standard part of the SOLCIOE screening. The Stereo Smile II test was added to the battery. Each subject was administered each stereo tests in a random order. BOth tests were administered in a forced choice design. Each test was presented at 50 cm, 6 trials were attempted and only the largest disparity card in the Smile test (480") was used. One investigator explained the procedure to the subjects and presented the targets while another assessed time to complete each test. A subject passed if they correctly located the target in >4 out of 6 trials for each test. Time was recorded in seconds.
Results: :
A comparison using the paired samples test revealed no significant difference in the amount of time needed to complete each task (t=1.304, p=.195). The mean time to complete the Smile test was 48.l7 sec (+/- 16.71) while the mean time to complete the RDE was 46.81 sec (+/-14.77). In addition, no difference in sensitivity, specificity, or PPV between the tests was observed. Testability was better with the Smile (95%) than the RDE (91.7%).
Conclusions: :
The Random Dot E Stereotest is a routinely used screening device when testing children and persons with ID. The Stereo Smile II test was introduced recently as a novel test which uses a smiling face rather than the letter E with the suggestion that patients would prefer the face. The Vision In Preschoolers study suggested that the Smile has an improved sensitivity while other studies have reported varying results. This study looked at the time to complete each test to see if one was more efficient. In addition the study will report on sensitivity and specificity with respect to strabismus, significant refractive error, and difference in acuity between the eyes as well as testability. Our study suggests that there is no difference in time to complete the tests.
Keywords: screening for ambylopia and strabismus • clinical (human) or epidemiologic studies: systems/equipment/techniques • strabismus: diagnosis and detection