Abstract
Abstract: :
Purpose: To investigate whether the positive prism test response is due to the pesence of a suppression scotoma or not. Methods: Fifty-one patients with esotropia (microtropia, small, moderate or large angle esotropia), and 22 patients with nonstrabismic anisometropic amblyopia were examined. The prism test was performed by using base-out prisms of three different powers (4-D, 10-D, 30-D), and base-in prism of 20-D, as well as base-down prism of 10-D for each patient. Results: All esotropic patients showed a positive prism test response, whereas all nonstrabismic anisometropic amblyopia patients had a negative prism test response. Conclusions: All esotropic patients having different sizes of deviation showed the positive response and there was no difference in responses by using the prisms of different powers and directions. Therefore, this test does not indicate suppression scotoma but merely indicate absence of bifoveolar fixation in esotropic patients.
Keywords: strabismus: diagnosis and detection • eye movements • eye movements: conjugate