Accommodation, pattern glare, and coloured overlays

Evidence for Overlapping Visual Processing Difficulties in Adult ADHD and Visual Stress

We investigated the viability of spectral filters as an adjunctive treatment for adults with both ADHD and visual processing difficulties. Fifty-nine adults (age 18-50), diagnosed with both ADHD and visual stress received either spectral filters (n = 39) or no intervention (n = 20) to address visual processing difficulties. We administered the MOXO d-CPT, a computer based continuous performance test, before the intervention and one hour after the intervention to assess any short-term change in the participants' attention profile. We used the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) before and 3-6 months after the intervention to assess any long-term intervention impact after 3-6 months. The intervention group had significant short- and long-term improvements in overall attention compared to the control group (X2(1, N = 59) = 20.10, p < .001). On the DSM-5, 49% of participants with short term and 64% with long-term intervention no longer met criteria for an ADHD diagnosis. Findings suggest that spectral filters may be an adjunctive treatment for many adults suffering from perceptually-based attention issues common to visual stress and ADHD.

Effect of spectral overlays on visual parameters and reading ability: an integrative review

ABSTRACT Purpose: to provide an integrative review of indexed articles published from 2009 to 2019 on the effect of spectral overlays on visual parameters and reading ability. Methods: keywords were used to search seven databases. Duplicate entries, reviews, literature reviews, editor's comments, and congress abstracts were excluded, as well as papers that were not relevant, based on their titles and abstracts. A total of 52 articles, which were read in full, were eligible at this stage. Of these, 12 articles, published in Portuguese or English from 2009 to 2019, were included. Results: all 12 articles included evaluated the effect of overlays on the reading rate. There was an improvement in different visual parameters (ocular accommodation and eye movement), facial recognition, and reading (reading rate, relative efficiency, and comprehension). The use of overlays reduced visual stress regardless of refractive, orthoptic or cognitive disorders. The associated conditions investigated were autism spectrum disorder, Tourette syndrome, stroke, deafness, dyslexia, and auditory temporal processing disorder. Conclusion: the effectiveness of overlays in improving reading quality is consistently demonstrated in the literature. The reviewed articles showed that the overlays’ effect is more expressive when the visual stress is associated with conditions that present sensory alterations and cortical hyperactivity.

Practice makes the deficiency of global motion detection in people with pattern-related visual stress more apparent

Aims

Pattern-related visual stress (PRVS) refers to the perceptual difficulties experienced by some individuals when exposed to high contrast striped patterns. People with PRVS were reported to have reduced sensitivity to global motion at baseline testing and the difference disappears at a second estimate. The present study was to investigate the effect of practice on global motion threshold in adults with and without PRVS.

Methods

A total of 101 subjects were recruited and the Wilkins & Evans Pattern Glare Test was used to determine if a subject had PRVS. The threshold to detect global motion was measured with a random dot kinematogram. Each subject was measured 5 times at the first visit and again a month later. Receiver operating characteristic (ROC) curve analysis was applied to show the agreement between the two tests.

Results

Twenty-nine subjects were classified as having PRVS and 72 were classified as normal. At baseline, the threshold to detect global motion was significantly higher in subjects with PRVS (0.832 ± 0.098 vs. 0.618 ± 0.228, p < 0.001). After 5 sessions, the difference between the normal and subjects with PRVS increased (0.767 ± 0.170 vs. 0.291 ± 0.149, p < 0.001). In ROC analysis, the area under the curve (AUC) improved from 0.792 at baseline to 0.964 at the fifth session. After a one-month break, the difference between normal and subjects with PRVS was still significant (0.843 ± 0.169 vs. 0.407 ± 0.216, p < 0.001) and the AUC was 0.875.

Conclusion

The ability to detect global motion is impaired in persons with PRVS and the difference increased after additional sessions of practice.

A Delphi study to develop practical diagnostic guidelines for visual stress (pattern-related visual stress)

PURPOSE

Visual stress (VS) is characterised by symptoms of visual perceptual distortions and eyestrain when viewing text, symptoms that are alleviated by individually prescribed coloured filters. A recent review supports the existence of VS and its treatment, but noted that controversy remains, in part due to inconsistencies in the diagnosis of the condition. The present paper reviews the diagnostic criteria for VS in the literature and reports a Delphi analysis of the criteria currently used in clinical practice.

METHODS

Twenty-six eyecare practitioners were invited to participate in a Delphi study. They were selected because they were frequent prescribers of precision tinted lenses. In the first round they were sent a list of the indicators for which there is literature to suggest a relevance in the diagnosis of VS. The practitioners were invited to rank the indicators and add any additional criteria they use in diagnosis. In the second round a revised list was circulated, including items added from the responses in the first round.

RESULTS

The respondents included optometrists, orthoptists and opticians. In the first round the response rate was 85%. Ninety-one percent of those who participated in the first round also responded in the second round. Strong indicators in the second round included the symptom of words moving when reading, voluntary use of an overlay for a prolonged period, improved performance of ≥15% with an overlay on the Wilkins Rate of Reading test, and an abnormally high score on the Pattern Glare Test.

CONCLUSIONS

The strongest diagnostic criteria are combined in a diagnostic tool. This is proposed as a guide for clinical practice and further research.

A systematic review of controlled trials on visual stress using Intuitive Overlays or the Intuitive Colorimeter

Claims that coloured filters aid reading date back 200 years and remain controversial. Some claims, for example, that more than 10% of the general population and 50% of people with dyslexia would benefit from coloured filters lack sound evidence and face validity. Publications with such claims typically cite research using methods that have not been described in the scientific literature and lack a sound aetiological framework. Notwithstanding these criticisms, some researchers have used more rigorous selection criteria and methods of prescribing coloured filters that were developed at a UK Medical Research Council unit and which have been fully described in the scientific literature. We review this research and disconfirm many of the more extreme claims surrounding this topic. This literature indicates that a minority subset of dyslexics (circa 20%) may have a condition described as visual stress which most likely results from a hyperexcitability of the visual cortex. Visual stress is characterised by symptoms of visual perceptual distortions, headaches, and eyestrain when viewing repetitive patterns, including lines of text. This review indicates that visual stress is distinct from, although sometimes co-occurs with, dyslexia. Individually prescribed coloured filters have been shown to improve reading performance in people with visual stress, but are unlikely to influence the phonological and memory deficits associated with dyslexia and therefore are not a treatment for dyslexia. This review concludes that larger and rigorous randomised controlled trials of interventions for visual stress are required. Improvements in the diagnosis of the condition are also a priority.