The Usefulness of Titmus Test and Distance Stereoacuity Using B-VAT(R) in Intemittent Exotropes

ABSTRACT

PURPOSE: Stereoacuity test is commonly used to determine the status of sensory function in patients with strabismus. We performed Titmus test and Mentor B-VAT II videoacuity tester in patients with basic or simulated divergence excess type intermittent exotropia {X(T)}, before and after surgery, to determine the effectiveness of near stereoacuity and the correlation between near stereoacuity and distance stereoacuity. METHODS: Near stereoacuity was measured using Titmus test and distance stereoacuity was measured using a Mentor B-VAT II videoacuity tester, before and after surgery, in 41 patients with X(T). RESULTS: The stereoacuity according to Titmus test was improved from a preoperative average of 70 seconds of arc to postoperative average of 60 seconds; however, this improvement was not statistically significant (P=0.38). Distance stereoacuity was significantly improved from a preoperative average of 221 seconds to a postoperative average of 60 seconds (P=0.001). No significant correlation was present between preoperative near stereoacuity and distance stereoacuity (P=0.99). CONCLUSIONS: Titmus test was not effective in determining the status of sensory function before and after surgery in patients with basic or simulated divergence excess type X(T). We believe that distance stereoacuity is effective in determining the status of sensory function.