Relationships between visual acuity and anomalous head posture in patients with congenital nystagmus

Purpose: To determine whether patients with congenital nystagmus and an anomalous head posture have better binocular visual acuity than such patients without an anomalous head posture. Patients and Methods: This was an observational case series of prospectively collected data for 125 patients with clinical and oculographically confirmed congenital nystagmus. Clinical data were tabulated using computer software. Statistical analyses compared binocular visual acuity with and without the presence of a clinically evident anomalous head posture and visual acuity with and without associated sensory disease. Results: The mean visual acuity was 20/42 (log of the minimal angle of resolution [MAR], 0.32) in patients with an anomalous head posture and 20/83 (logMAR, 0.62) in patients with no anomalous head posture (P < .001). Among patients with disease of the sensory system, those with an anomalous head posture had a mean visual acuity of 20/55 (logMAR, 0.44) and those without an anomalous head posture had a mean visual acuity of 20/108 (logMAR, 0.73; P < .001). Conclusions: Visual acuity was found to be significantly better in patients with congenital nystagmus who had an anomalous head posture versus those without such a head posture. Our findings indicate that the presence of an anomalous head posture in a patient with congenital nystagmus correlates with good vision and thus may be considered a positive prognostic sign in a preverbal child.