Sighting dominance, retinal nerve fiber layer and macula; are they related? - An ocular dominance analysis study

The purpose of this study was to study ocular dominance and its association with retinal nerve fiber layer (RNFL) and macular thickness.

A cross-sectional study was conducted on 432 participants with nonpathological eyes. We determined the ocular dominance by the hole-in-card test (Dolman method). A comprehensive eye examination was conducted on the participants, including best-corrected visual acuity, intraocular pressure, and anterior and posterior segment examination. The RNFL thickness was measured using optical coherence tomography. The findings were analyzed using paired t-tests to compare between dominant and nondominant eyes.

Out of the 432 participants, 70.4% (304) showed right eye dominance of study population had right eye dominance. The average RNFL (AvRNFL) thickness showed a small but significantly higher value in dominant eyes compared to nondominant eyes. We found significantly higher RNFL thickness in temporal, inferior and nasal quadrants in dominant eyes compared to nondominant eyes. Age had minimal effect on the difference in AvRNFL thickness between dominant and nondominant eyes (P = 0.144). There was no significant difference in macular retinal thickness between the eyes.

Ocular dominance was found predominantly in the right eye. The dominant eye showed greater AvRNFL thickness compared to nondominant eye. AvRNFL, inferior RNFL, Nasal RNFL, Temporal RNFL thickness were greater in the dominant eye compared to the nondominant eye. There was no difference in macular thickness. Our findings suggest the need to consider dominance in various disease entities, in clinical decision making and normative data particularly concerning retinal nerve fiber layer.