Comparison of strabismus angle measured with Alternate Prism Cover test and Krimsky test using accommodative target

Abstract

Purpose: To determine the effect of accommodative target in Krimsky test and comparison of results with  conventional Krimsky test and prism cover test at near considering it the actual angle of deviation. Methods: 50 patients with only horizontal manifest strabismus, 25 with exotropia and 25 with esotropia were considered. Visual acuity was recorded without glasses with VLC monitor. Extraocular movements recorded in six cardinal positions of gaze. Krimsky test was performed with light target and then angle was measured when patient fixating on accommodative target. Alternate prism cover test was performed at both distance and near fixation and considered as the actual deviation of the patient. Results: Angle of deviation measured with three different methods was compared. In esotropia, Krimsky test showed significant under correction of the near deviation (P=0.00) and Krimsky test with accommodative target showed no significant difference (P=0.574) when compared with alternate prism cover test. In exotropia, Krimsky test slightly overcorrected (P=.07) and Krimsky test with accommodative target significantly overcorrected (P=0.00) the near angle of deviation when compared with alternate prism cover test. Conclusion:  Krimsky test with accommodative target is nearly equal to prism alternate cover test for measurement of near deviation in esotropia but shows significant overcorrection in exotropia.