Stereopsis Checking Software Development And The Size Of The Random Dot Stereoacuity Of Visually Impaired Children

Objective: To test the accuracy of the Personal Computer-Random dot Stereogram(PC-RDS), study the effect of the size of random dot on the stereoacuity of amblyopia. Method: We tested the stereoacuity of 219 children (34 normals and 185 amblyopia ) with PC-RDS and TNO and found that there was no statistical difference between two methods . Then we selected randomly 251 amblyopia and divided them into two groups according their corrected vision(A 75 corrected vision 0.25-0.6; B 176 corrected vision > 0.6). We tested the stereoacuity of A group at 60cm and B group at 2m with PC-RDS when the size of the random dot is changed (2, 4, 6, 8, 10 pixels). Results: 1) There was no distinct difference between TNO and PC-RDS(P> 0. 05). 2)The abnormity of stereoacuity of different types of amblyopia was different(P<0.05). 3)There was no statistic changes of stereoacuity of amblyopia in the distance of 60cm when we changed the size of the random dot(P > 0.05).4)In the distance of 2m,the changes of the stereoacuity of ametropia amblyopia was distinct when the size of random dot ranging from 2 to 10 pixels(P<0.05), while there were no statistical changes of the stereoacuity of anisometropia and strabismus amblyopia. Conclusion: 1) PC-RDS is as accurate as TNO and can be used in clinical test and basic research; 2) In the distance of 60cm, the size of random dot has no effect on the stereoacuity of amblyopia. 3) In the distance of 2m, the size of random dot has effect on the stereoacuity of ametropia amblyopia, while the effect on the anisometropia and strabismus amblyopia is not distinct. 4) Wether the size of random dot has effect on the all three types of amblyopia when the distance is far than 2m is still keep unknown and we will study it futher.