A variety of assessment procedures have been developed to evaluate saccades. Tests may involve direct observation by the clinician, timed/standardized tests involving a visual–verbal format, and objective eye movement recording using electrooculographic instruments. However, there are advantages and disadvantages associated with all three of these methods. Infrared limbal sensing procedures such as the Readalyzer and the Visagraph II are expensive and may be difficult to use with elementary schoolchildren. Subjective techniques involving observation of the patient’s eye movements have been developed along with rating scales. These rating scales are subjective, and inexperienced clinicians may have difficulty learning to use them effectively. Another problem with this approach is that the gross eye movements observed using these procedures may not correspond well to the eye movements used when reading. Although some questions have been raised in the past about the reliability and repeatability of subjective rating scales, a study by Maples (72) showed that the rating scale used for the NSUCO (Northeastern State University College of Optometry) oculomotor test is reliable and repeatable.

The test we recommend in this category is the NSUCO oculomotor test, which is the first standardized direct observation test that has been developed. The test includes a standardized instructional set, a description of the appropriate targets, instructions about target placement, a standardized scoring system, and normative data. Direct observation tests require the subject to look from one object to another while the clinician observes the patient’s saccades.

For the saccadic testing portion of the NSUCO oculomotor test, the patient is asked to stand directly in front of the examiner. Two targets are used and held at the Harmon distance or no farther than 40 cm from the patient. The examiner holds the targets so that each target is about 10 cm from the midline of the patient and asks the patient to look from one target to another on command. This is repeated until the patient makes five round-trips or 10 fixation movements from one target to another. No instructions are given to the patient to move or not to move his or her head.

The examiner observes the saccadic eye movements and rates the performance in four categories: head movement, body movement, ability, and accuracy (Table 1.10). Although several rating scales have been developed to create better uniformity in observation (3,73,74), only the NSUCO oculomotor test has been shown to be both reliable and repeatable (74). Table 1.11 shows normative data for this test.

Direct observation testing is a useful starting point in the evaluation of saccades. Maples (72) suggests that if the patient fails this test, a clinician can feel comfortable suspecting an oculomotor dysfunction. However, if a patient passes the test, this does not rule out an oculomotor dysfunction. If the history suggests an eye movement disorder, additional testing such as visual–verbal format testing or objective eye movement recording should be performed.