Abstract
Purpose :
Sensory ocular dominance can be very asymmetric, hardly discernable, or somewhere in between. Factors that determine sensory ocular dominance have yet to be completely determined. A relationship between anisometropia and sensory ocular dominance has been shown. Greater asymmetry in ocular dominance may develop in axial anisometropia due to a difference in optic nerve size, which may lead to a difference in signal strength to the brain from the two eyes. Whether a relationship exists between sensory ocular dominance and anatomic parameters of the optic nerve head (ONH) as measured by optical coherence tomography (OCT) is unknown.
Methods :
Sensory ocular dominance was determined for 85 young healthy adults, aged 20-35 years, without amblyopia, using the +2.00D monocular blur during binocular viewing test. Area of both optic nerve heads (ONH) of each subject was measured by spectral domain optical coherence tomography (SD-OCT). Subjects with ocular dominance were assigned to 1 of 2 groups: dominant eye larger (DEL), non-dominant eye larger (NDEL). The binomial probability that the sensory dominant eye would be the same as the eye with the larger area ONH by OCT was calculated.
Results :
Sensory ocular dominance was identified in 70 subjects (82.4%); 15 subjects did not manifest a preferred eye. Forty-three of subjects manifesting a sensory dominant eye (61.4%) had sensory dominance identified for the eye with the larger ONH by OCT. The test of binomial probabilities showed that the likelihood of occurrence of this proportion (or greater) of subjects with sensory ocular dominance manifested by the eye with the larger ONH area by OCT is greater than chance (p = 0.036; z = 1.79).
Conclusions :
Our pilot data on the relationship between sensory ocular dominance and ONH area measured by OCT suggests qualitatively that an interocular difference in optic nerve size may be a contributing factor to the establishment of which eye demonstrates sensory ocular dominance as assessed by the +2.00 monocular blur test. Whether similar findings with other tests of sensory dominance is unknown. A larger study of multifactorial contributions to sensory ocular dominance that includes evaluation of ONH anatomy and function is indicated.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.