Assessment of neuro-optometric rehabilitation using the Developmental Eye Movement (DEM) test in adults with acquired brain injury

Characteristics of binocular vision and oculomotor function among sports-concussed athletes

Purpose

To compare the binocular vision and oculomotor function between sports-concussed athletes and aged-matched controls.

Methods

Thirty mild concussed athletes were recruited and compared with aged-matched controls. All the participants underwent a comprehensive ocular assessment followed by an oculomotor assessment which included tests for accommodation, vergence, eye movements, and reading parameters.

Results

Three categories of oculomotor-based deficits were found: convergence insufficiency (40%), accommodative insufficiency (25%), and oculomotor-based reading dysfunctions (20%). A statistically significant reduction in the mean ± SD of the following parameters was noted in concussed athletes v/s controls:- binocular accommodative amplitude: 7.13 ± 1.59 v/s 15.35 ± 2.95 (P < 0.001), convergence amplitude: 14.23 ± 5.00 v/s 5.65 ± 0.90 (P < 0.001), positive fusional vergence for distance: 21.17 ± 8.97 v/s 31.32 ± 6.23 (P < 0.001), vergence facility: 6.47 ± 1.47 v/s 11.84 ± 1.00 (P < 0.001), accommodative facility: 7.10 ± 4.57 v/s 11.67 ± 1.83 (P < 0.001), reading speed: 66.97 ± 17.82 v/s 144.13 ± 24.45 (P = 0.03) and Developmental Eye Movement ratio: 1.40 ± 0.19 v/s 1.17 ± 0.06 (P < 0.001).

Conclusion

Concussions caused by sports have a considerable impact on binocular vision and oculomotor parameters. These findings have substantial therapeutic implications in terms of establishing a periodic screening program for athletes so that essential therapy can be provided for a better outcome.

Normative Values of the Groffman Visual Tracing Test for the Assessment of Oculomotor Performance in the Adult Population

The Groffman visual tracing (GVT) test is an indirect psychometric measure of oculomotor performance, used for the clinical assessment of eye movements. The test consists of two cards with five contorted lines of increasing overlap, crowding, and difficulty. The task starts from each of the letters at the top of the page, follows the line from the letter to the corresponding number at the bottom of the page, and the number is named. Although the GVT test was developed for the evaluation of children, it has also been applied to adults with visual and cognitive deficits. However, it lacks reference values. Therefore, the aim of the study was to assess oculomotor behavior across the typical human lifespan and to define normative data in an adult population. A total of 526 adults aged between 20 and 79 years, all without neurological or psychiatric deficits, were enrolled in the study. The results were analyzed by considering the accuracy and execution times separately. An influence of age, education and sex for accuracy was found, and age for the execution times was found. Norms for adults were developed considering the specific structure of the test and the accuracy and the execution time separately. The GVT test can now be applied in healthy and neurological adult populations for the evaluation of oculomotor performance.

Validation of a modified version of the adult developmental eye movement test

This study evaluates in terms of reliability, internal consistency, and validity a modification of the Adult Developmental Eye Movement (ADEM) test, ADEM with distractors (ADEMd), designed to analyse oculomotor system, visual processing and visual attentional behaviour. 302 healthy subjects participated in the study (20–86 years old). Intrasession repeatability was evaluated by analysing the correlation between the time needed to read different parts of the test. Inter-session analyses were carried in 40 subjects by calculating intraclass correlation coefficients and using the Bland–Altman method. Validity was assessed in the outcomes obtained according to age as well as investigating the correlation between ADEMd and attentional useful field of vision (UFOV) test. Correlation coefficients between times need to read each sheet were ≥ 0.95 (p < 0.001). The inter-session intraclass correlation coefficient ranged from 0.81 in the horizontal distractor sheet to 0.97 in the vertical sheet. Bland–Altman analysis showed clinically acceptable limits of agreement. Statistically significant correlations were found between age and ADEMd outcomes (r ≥ 0.55, p < 0.001). Processing velocity, divided attention and selective attention measured with the UFOV were correlated with the horizontal distractor times (r ≥ 0.32, p < 0.001). ADEMd test may be a useful clinical tool to evaluate the combined interaction of ocular movements and visual attentional behaviour.

Neuroplasticity pathophysiological mechanisms underlying neuro-optometric rehabilitation in ischemic stroke – a brief review

Neuroplasticity is an essential phenomenon underlying on neurorehabilitation process, by which the brain can remodel the dysfunction consequent to a lesion. Ischemic brain lesions are the most frequent brain lesions often associated with visual function disability. Experimental and clinical studies established that visual function disability can impede the neurorehabilitation therapy efficiency. Neuro-optometric therapy has been proved to significantly improve the patient outcome after brain lesions. The pathophysiological mechanisms underlying this process are yet to be deciphered. Current knowledge regarding the pathophysiological mechanisms involved in ischemic lesions and neuroplasticity as a reparation process offers real support to a more efficient neurorehabilitation therapy that can contribute to the improvement of life quality in stroke patients. Keywords: neuroplasticity, neuro-optometric rehabilitation, ischemic stroke,

Spotlight on the Developmental Eye Movement (DEM) Test

The developmental eye movement (DEM) test is a practical and simple method for assessing and quantifying ocular motor skills in children. In this review, a summary of the literature relevant to the DEM test has been made, its psychometric properties and its pros and cons have also been considered. The DEM test provides clinicians with a simple method of measuring eye movement using a psychometric test. Over the years, many studies have enabled the identification of the strengthens and weaknesses of this test apart from outlining the psychometric properties. The validity of the test has been checked and expanded over time and studies have shown that the DEM test measures an aspect of eye movement related to reading, rather than purely parameters associated with eye-movement. Some reservations have emerged regarding the repeatability of the test because a degree of learning effect emerges over multiple sessions. Being aware of this point allows correct clinical application and interpretation of the test. Normative data in children were available for nine languages and countries. So far, DEM test could be applied clinically in each case when a rapid test of eye movement was required, such as in testing for vision-related visual problems.

An Extended Method for Saccadic Eye Movement Measurements Using a Head-Mounted Display

Saccadic eye movementis an important ability in our daily life and is especially important in driving and sports. Traditionally, the Developmental Eye Movement (DEM) test and the King-Devick (K-D) test have been used to measure saccadic eye movement, but these only involve measurements with "adjusted time". Therefore, a different approach is required to obtain the eye movement speed and reaction rate in detail, as some are rapid eye movements, while others are slow actions, and vice versa. This study proposed a extended method that can acquire the "rest time" and "transfer time", as well as the "adjusted time", by implementing a virtual reality-based DEM test, using a FOVE virtual reality (VR) head-mounted display, equipped with an eye-tracking module. This approach was tested in 30 subjects with normal vision and no ophthalmologic disease by using a 2-diopter (50-cm) distance. This allowed for measurement of the "adjusted time" and the "rest time" for focusing on each target number character, the "transfer time" for moving to the next target number character, and recording of the gaze-tracking log. The results of this experiment showed that it was possible to analyze more parameters of the saccadic eye movement with the proposed method than with the traditional methods.

Systematic review of visual rehabilitation interventions for oculomotor deficits in patients with brain injury

Purpose: Secondary to brain injury, many people develop eye movement disorders (oculomotor deficits). To clarify, optimize, and standardize the development of oculomotor rehabilitation programs, we systematically reviewed the literature on vision rehabilitation interventions for oculomotor deficits in brain injury, focusing on those with broad clinical feasibility.Materials and Methods: We searched MEDLINE (PubMed), CENTRAL, Scopus, and CINAHL databases for key title terms "oculomotor", "rehabilitation", or a related term, and "brain injury" or a related term in the title or abstract. We excluded case reports of a single patient, studies of non-oculomotor visual deficits, and articles in which the intervention and assessment methods were not explicitly identified.Results: Nine articles were included, six of which utilized computer-based training programs to elicit characteristic fixation, saccades, pursuit, vergence, and accommodative movements. Within the entire sample, interventions ranged from 3 to 10 weeks, and involved 2 to 5 training sessions per week.Conclusions: Oculomotor rehabilitation interventions showed some efficacy in treating patients with brain injury; however, there were very few studies overall. Several eye movement types - fixation, saccades, pursuit, vergence, and accommodation - can be elicited manually by therapists. We eagerly await the development and implementation of new intervention programs for broad-based clinical practice.