Optometric correlates of Meares-Irlen syndrome: a matched group study.
People who report visual perceptual distortions, typically when reading, that are alleviated by using coloured filters are described as suffering from 'Meares-Irlen Syndrome'. A recent double-masked placebo-controlled trial showed that this condition cannot be solely explained as a placebo effect and that the beneficial filter is idiosyncratic and sometimes needs to be highly specific. Several mechanisms have been suggested for Meares-Irlen Syndrome including ocular motor (binocular and accommodative) anomalies, a sensitivity to patterned stimuli (pattern glare), and a deficit of the transient visual sub-system. We investigated these hypotheses by comparing 16 children, who reported the symptoms described above and who showed a sustained benefit from coloured filters, with 25 control children who came from the same school and were matched for age, reading performance and intelligence. The 'Meares-Irlen Syndrome' group had slightly, but significantly, reduced vergence and accommodative amplitudes and stereo-acuity; they also demonstrated significantly more pattern glare. The two groups did not differ significantly in their visual acuities, refractive error, dissociated or associated heterophoria, AC/A ratio, or ability to perceive 20 Hz flicker. It appears that certain ocular motor factors are correlates of Meares-Irlen Syndrome, rather than the primary underlying cause of the symptoms. The results support the hypothesis that pattern glare may be involved in the mechanism of Meares-Irlen Syndrome.
Evans
B J
BJ
Institute of Optometry, London, UK.
Busby
A
A
Jeanes
R
R
Wilkins
A J
AJ
D000065:Accommodation, Ocular / Q000502:physiology; D001248:Asthenopia / Q000503:physiopathology*; D002648:Child; D003290:Convergence, Ocular / Q000502:physiology; D004410:Dyslexia / Q000503:physiopathology; D005425:Flicker Fusion / Q000502:physiology; D006801:Humans; D010468:Perceptual Disorders / Q000503:physiopathology*; D010469:Perceptual Distortion / Q000502:physiology*; D011594:Psychometrics; D012684:Sensory Thresholds; D013285:Strabismus / Q000503:physiopathology; D013577:Syndrome; D014792:Visual Acuity