Development of a simple computerized torsion test to quantify subjective ocular torsion.

PurposeThe double Maddox-rod test (DMRT) and Lancaster red-green test (LRGT) are the most widely used tests worldwide to assess subjective ocular torsion. However, these tests require equipment and the quantified results of ocular torsion are only provided in rough values. Here we developed a novel computerized torsion test (CTT) for individual assessment of subjective ocular torsion and validated the reliability and accuracy of the test compared with those of the DMRT and LRGT.MethodsA total of 30 patients with cyclovertical strabismus and 30 controls were recruited. The CTT was designed using Microsoft Office PowerPoint. Subjects wore red-green filter spectacles and viewed gradually tilted red and cyan lines on an LCD monitor and pressed the keyboard to go through the slides, until both lines seemed parallel. All subjects underwent the CTT, DMRT, and LRGT. Intraclass correlation coefficients and Bland-Altman plots were analyzed to assess the acceptability of the CTT compared with that of the DMRT.ResultsBoth the DMRT and CTT showed no significant test-retest differences in the strabismus and control groups. The DMRT and CTT results demonstrated an acceptable agreement. The reliability of the CTT was better than that of the DMRT. The LRGT showed low sensitivity for the detection of ocular torsion compared with the DMRT (40.0%) and CTT (39.1%).ConclusionOur results suggest that the assessment of subjective ocular torsion using the CTT based on PowerPoint software is simple, reproducible, and accurate and can be applied in clinical practice.