2020–2021 BCSC Basic and Clinical Science Course™
6 Pediatric Ophthalmology and Strabismus
Part I: Strabismus
Chapter 7: Diagnostic Evaluation of Strabismus and Torticollis
Assessment of Ocular Alignment
Diagnostic Positions of Gaze
The diagnostic positions of gaze are a core set of 9 different gaze positions used in the comprehensive assessment of ocular alignment. They consist of
primary position: The eyes fixate straight ahead on an object at infinity, which, for practical purposes, is considered to be 6 m, or 20 ft. For this position, the head should be straight.
6 cardinal positions: Two muscles (1 in each eye) are the prime movers of their respective eyes into each of these positions of gaze (see Chapter 4).
straight up and straight down: These do not isolate any single muscle, because the actions of both oblique and vertical rectus muscles affect elevation and depression from primary position; see Chapter 4.
For patients with vertical strabismus, the diagnostic positions of gaze also include forced head tilt toward the right shoulder and the left shoulder (see the section The 3-Step Test, later in this chapter). Near fixation (usually 33 cm in the primary position) and reading position (depending on the patient’s symptoms) complete the list of clinically important test positions.
Tests for measuring ocular alignment can be grouped into 3 basic types: cover tests, corneal light reflex tests, and subjective tests.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.