Comparison of functional, structural and vascular characteristics between dominant and nondominant eyes

The aim of this study was to compare retinal and optic disc functions as well as vascular structures in dominant eyes (DE) and non-dominant eyes (NDE) among healthy adults using pattern electroretinogram (PERG), optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) tests. Seventy-two eyes of 36 healthy subjects with bilateral visual acuity of 1.0 were included. Parameters such as intraocular pressure (IOP), cycloplegic spherical equivalent value (SE), PERG, retinal nerve fiber layer (RNFL) thicknesses and OCTA measurements were evaluated. Ocular dominance was determined using the hole-in-the-card test. Of the participants, 67% were female, with a median age of 28 (min-max.18-35) years. Right eye dominance was observed in 61.2% of cases, while left eye dominance was seen in 38.8%. There was no significant difference in refractive values between eyes with right and left eye dominance (0.60 ± 0.40 and 0.41 ± 0.28, p = 0.42). The dominant eyes showed significantly higher P50 amplitude (10.2 µV vs. 9.2 µV, p = 0.003) and shorter peak time (47.9 ms. vs. 48.6 ms, p = 0.01) when compared to the nondominant eyes. There were comparable values in the peak times and amplitudes of the N95 component between the dominant and nondominant eyes. The RNFL layer was thicker on average (p, 0.001) as well as in the nasal and inferior quadrants of the dominant eyes (p 0.05), except for the deep whole capillary density in the macula, which was significantly higher in the dominant eyes (p = 0.02). Our results indicate the existence of functional and structural relationships related to ocular dominance. Future studies provide further insights into ocular dominance and its relationship with eye structure.