Oculomotor Dysfunctions: Evidence-Based Practice

Professional perspective and practice patterns of vision therapy in Spain

CLINICAL RELEVANCE

An analysis of the professional perspective of vision therapy (VT) by eye care professionals allows understanding the current controversies about this therapeutic option of which aspects can be improved for its correct application in clinical practice.

BACKGROUND

The aim of the current study was to analyse the perception of VT and the clinical protocols in this context followed among optometrists and ophthalmologists in Spain.

METHODS

A cross-sectional survey among Spanish optometrists and ophthalmologists. Google Forms tool was used to collect data via an online questionnaire divided into 4 sections (40 questions): consent to participate, demographic characteristics, opinion of the professional perspective of VT, and protocols. Only one submission from each email address was permitted by the survey tool.

RESULTS

A total of 889 Spanish professionals answered (age, 25-62 years): 848 optometrists (95.4%) and 41 ophthalmologists (4.6%). VT was considered as a scientifically-based procedure by 95.1% of participants, but its recognition and prestige was considered as low. The main cause reported for this was bad reputation or perception of placebo therapy (27.3%). The main indication of VT according to the surveyed professionals was convergence and/or accommodation problems (72.4%). Significant differences were found in the perception of VT among optometrists and ophthalmologists (p ≤ 0.027). A total of 45.3% of professionals reported performing VT in their current clinical practice. A combination of training sessions in office and home was regularly prescribed by 94.5% of them, but with significant variability in the duration of such sessions.

CONCLUSIONS

VT is perceived by Spanish optometrists and ophthalmologists as a therapeutic option with scientific basis, but with limited recognition and prestige, although with more negative perception among ophthalmologists. A great variability was found in the clinical protocols followed between specialists. Future efforts should be focused on creating internationally recognised evidence-based protocols for this therapeutic option.

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.

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.

Clinical Characterization of Oculomotricity in Children with and without Specific Learning Disorders

Children with specific learning disorders have been associated with oculomotor problems, with their analysis even suggested to be a potential diagnostic tool. A prospective non-randomized comparative study evaluating 59 children (6–13 years old) divided into three groups was conducted: a control group (CG) including 15 healthy emmetropic children; a group of 18 healthy children with oculomotor abnormalities (OAG); and a group of 26 children diagnosed with specific learning disorders (LDG). In all groups, besides a complete eye exam, oculomotricity was characterized with two clinical tests: Northeastern State University College of Optometry’s Oculomotor (NSUCO) and Developmental Eye Movement (DEM) tests. Concerning the NSUCO test, lower ability, precision, and head/body movement associated scorings were obtained for both smooth pursuits and saccades in OAG and LDG when compared to the CG (p < 0.001). Likewise, significantly longer time needed to read the horizontal sheet of the DEM test and a higher DEM ratio were found in OAG and LDG compared to CG (p ≤ 0.003). No differences between LDG and OAG were found in the performance with the two oculomotor tests (p ≥ 0.141). Oculomotor anomalies can be present in children with and without specific learning disorders, and therefore cannot be used as diagnostic criteria of these type of disorders.