Pediatric Visual Acuity Strategies: Induced Tropia Test

Induced Tropia Test. Using a 10-20 base-down prism, this exam demonstrates equal vision in both eyes. If there is evidence of ocular misalignment, prisms can be used to neutralize the movement and thereby measure the deviation, whether it is a heterotropia or heterophoria. Prisms are placed in front of either eye such that the apex of the prism is oriented in the direction of the deviation, and the prism strength is altered until the deviation is no longer observed. This video supplements Paediatric Neuro-ophthalmology: Visual Acuity Assessment Strategies: https://collections.lib.utah.edu/ark:/87278/s6vh9z9

Vertical optokinetic nystagmus

Visual depiction of the vertical OKN drum test. The vertical optokinetic drum test is an exam used to elicit vertical optokinetic nystagmus (OKN) when there is horizontal nystagmus. The hand-held "optokinetic" drums or tapes that are used to elicit smooth movements primarily test the pursuit system. This video supplements Paediatric Neuro-ophthalmology: Visual Acuity Assessment Strategies: https://collections.lib.utah.edu/ark:/87278/s6vh9z9

Paediatric Neuro-ophthalmology: Visual Acuity Assessment Strategies

Assessing the visual function of a child can be challenging at times. When approaching a child one must understand visual development and accommodate to the child's capabilities, level of development and communication skills. The examining physician may need to apply more than one method to assess the child's visual acuity. Several techniques are presented here in an incremental fashion, demonstrating methods that are suitable from very early infancy to late childhood. The tools that are provided should assist the reader in becoming a more competent examiner. See accompanying videos: Induced Tropia Test: https://collections.lib.utah.edu/ark:/87278/s6090fs9; Horizontal right optokinetic nystagmus: https://collections.lib.utah.edu/ark:/87278/s6qr96mk; Vertical optokinetic nystagmus: https://collections.lib.utah.edu/ark:/87278/s6m3756