Result of prismatic lenses in the treatment of congenital nystagmus: case report

Introduction: Nystagmus is characterized by an involuntary shaking or jerking of the eyes idiopathic or associated with defects of the visual afferent system, which usually results in some degree of visual loss. Congenital motor nystagmus onset is typically between 6 weeks and 3 months of age. Patients with nystagmus often hold their heads in a head abnormal position (HAP), in an effort to maintain a null point - a position whereby eye movement is minimized that reduces the nystagmiform movements. They turn the head to the left while looking to the right or to right, while looking to the left, improving the vision in this position. The use of prismatic lenses with opposite bases placed in the opposite direction to the direction of the look in which the nystagmus decreases, reduces the HAP, and improves visual acuity (VA). The power must be in accordance with the patient's fusional ability to avoid diplopia. Aim of the study: To describe the evolution and impact on VA and HAP, of the use of opposing base prisms for 5 years, in a child with congenital motor nystagmus.