Elucidation of the more myopic eye in anisometropia: the interplay of laterality, ocular dominance, and anisometropic magnitude

This study reveals how, in a myopic anisometrope, the odds of an eye being more myopic are related to laterality, ocular dominance, and magnitude of anisometropia. In 193 subjects, objective refraction was performed with cycloplegia. Sighting, motor, and sensory dominance were determined with the hole-in-the-card test, convergence near-point test, continuous flashing technique, respectively. Multiple logistic regression was used for probability analysis. Seventy percent of the subjects had a right eye that was more myopic, while 30% of them had a more myopic left eye. When the right eye was the sensory dominant eye, the probability of the right eye being more myopic increased to 80% if the anisometropia was less than 3.0 D, and decreased below 70% if anisometropia was beyond 3.0 D. When the left eye was the sensory dominant eye, the probability of the left eye being more myopic increased to above 40% if the anisometropia was less than 4.0 D and decreased below 30% if the anisometropia was beyond 4.0 D. Therefore, between the two eyes of anisometropes, laterality tilts the chance of being more myopic to the right. Being the sensory dominant eye increases an eye's probability of being more myopic by another 10% if the magnitude of anisometropia is moderate.