[Basic methods of strabismology]

Basic examination techniques for manifest and latent strabismus as well as for paralytic strabismus are discussed. Usually the medical history gives the first clues for the form of strabismus. The examination starts with an evaluation of the head posture. The objective angle is estimated through corneal reflections and the corrective saccade (cover test). Uncover and cover testing allows the differentiation between manifest and latent strabismus. The Lang test, Bagolini's test and the light red glass test provide information regarding quality of binocularity (abnormal and normal retinal correspondence). Estimation of changes in the angle of strabismus in the diagnostic gaze positions by corneal reflections, cover test and the limbus test of Kestenbaum is complemented by testing of the visual acuity and fixation. Without evaluation of fixation neither the cover test nor tests for binocularity can be interpreted adequately.