Question

Explain how to assess for extraocular muscle function:

(a) corneal light reflex test (Hirschberg Test);
(b) Cover test;
(c) Diagnostic Positions Test (Six Cardinal Fields of Gaze).

Explain the reason for assessing extraocular muscles function and explain the expected (normal) results for these tests.

Answer 1

The corneal light reflex test, cover test, and diagnostic positions test are used to assess extraocular muscle function. These tests evaluate eye alignment, movement, and coordination. Normal results would show symmetrical and coordinated eye movements.

Step-by-step explanation:

Assessing Extraocular Muscle Function

There are several tests used to assess extraocular muscle function:

1. Corneal Light Reflex Test (Hirschberg Test): This test involves shining a light into the patient's eyes and observing the reflection on the cornea. The position of the reflection can indicate any misalignment of the eyes.
2. Cover Test: This test involves covering one eye at a time while the patient focuses on a target. The cover is then quickly switched to the other eye to observe for any eye movement or misalignment.
3. Diagnostic Positions Test (Six Cardinal Fields of Gaze): In this test, the patient is asked to follow a target as it moves in six different positions. This helps assess the strength and coordination of the extraocular muscles.

The purpose of assessing extraocular muscle function is to evaluate the coordination and alignment of the eyes. Normal results for these tests would show a symmetrical and coordinated movement of both eyes, with no misalignment or abnormality.