Oculomotor Dysfunctions in Nonreading Tasks in Children With Dyslexia: Saccadic and Optokinetic Findings


Üçok M. S., Dinçer M., KARAÇAYLI C., Bağlıcakoğlu E. G., Ayaroğlu P., BODUR Ş., ...Daha Fazla

International Journal of Developmental Neuroscience, cilt.86, sa.3, 2026 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 86 Sayı: 3
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1002/jdn.70132
  • Dergi Adı: International Journal of Developmental Neuroscience
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, EMBASE, MEDLINE, Academic Search Ultimate (EBSCO)
  • Anahtar Kelimeler: dyslexia, eye movement, oculomotor control, optokinetic response, reading disability, saccades
  • Sağlık Bilimleri Üniversitesi Adresli: Evet

Özet

Background: Dyslexia has been associated with atypical eye–movement control, but whether such differences arise only during reading or reflect broader oculomotor control remains debated. Methods: We compared 40 children with dyslexia and 40 age/sex matched controls (8–12 years). Binocular eye movements were recorded with infrared video-oculography (VOG) using a clinical VNG platform's oculomotor module. Participants performed a random-step horizontal saccade task (targets at ±15° and ±20° from midline (step amplitudes 5°–40°); pseudo-random 3–4 s intervals). Saccades were detected with manufacturer thresholds (40°/s, 800°/s2). Primary outcomes were peak velocity (°/s), accuracy (%) and latency (ms); optokinetic responses (OKR) were analysed for each eye, and we report the interocular OKR difference (%). Trials with blinks/track-loss were excluded a priori. Results: Compared with controls, children with dyslexia showed slower saccades (307.5°/s vs. 453.5°/s), lower accuracy (71.5% vs. 98.5%) and longer latency (260.0 vs. 131.5 ms), all p < 0.001. Right-eye OKR was reduced, whereas left-eye OKR did not differ significantly, and the interocular OKR difference was significantly larger in dyslexia. These group differences remained significant after adjustment for relevant socio-demographic covariates. Conclusions: Children with dyslexia exhibited robust oculomotor differences during a nonreading task, consistent with altered visually guided saccade control. These results are associative rather than causal and suggest that oculomotor measures may provide complementary insight into dyslexia.