BACKGROUND: To investigate the relationship between ocular and hand dominance patterns in healthy volunteers and to evaluate structural differences between dominant and non-dominant eyes using anterior and posterior segment measurements. METHODS: This cross-sectional study included 524 healthy volunteers (50% female, age 20-60). Ocular dominance was determined using the hole-in-card test and hand dominance with the Edinburgh Handedness Inventory. Participants underwent Swept-Source Optical Coherence Tomography for retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), subfoveal choroidal thickness (SFCT), and choroidal vascularity index (CVI) measurements; Scheimpflug imaging for anterior segment parameters; and partial coherence interferometry for axial length determination. RESULTS: Right eye dominance was observed in 60.9% and left eye dominance in 39.1% of participants. A pronounced cross-lateralization pattern emerged: 93.6% of left eye dominant individuals exhibited right hand dominance, significantly higher than in right eye dominant participants (57.1% right-handed, p = 0.024; 42.9% left-handed, p = 0.016). After correction for multiple comparisons, dominant eyes demonstrated significantly greater central corneal thickness (p = 0.002). RNFL nasal quadrant thickness showed the strongest trend toward significance (p = 0.014). Axial length, additional RNFL quadrants, and GCC sectors demonstrated consistent trends toward significance. No differences were found in SFCT or CVI. CONCLUSIONS: Dominant eyes demonstrated significantly greater central corneal thickness after correction for multiple comparisons, with nasal RNFL thickness showing the strongest trend toward significance. A differential lateralization pattern was observed between ocular dominance groups, suggesting a potential association between ocular and manual preferences; however, this finding warrants cautious interpretation given the population-level prevalence of right-handedness. TRIAL REGISTRATION: This cross-sectional study was approved by the Institutional Ethics Committee of İzmir Democracy University, Buca Seyfi Demirsoy Training and Research Hospital (date: 26.03.2025; number: 2025/427) and adhered to the principles of the Declaration of Helsinki.
Kıyat et al. (Wed,) studied this question.