Pupillography of Relative Afferent Pupillary Defects in Amblyopia Associated With Peripapillary Myelinated Nerve Fibers and Myopia

Abstract

Purpose: : To investigate whether patients with unilateral myelinated nerve fibers and amblyopia, in whom pupillary responses are often reported to be normal, have afferent pupillary defects.

Methods: : Three patients with unilateral peripapillary myelinated nerve fibers associated with high myopia and amblyopia (three women, aged 11–38 years) were examined. Pupillary responses to light in each patient were recorded during an automated swinging flashlight test with binocular infrared video pupillography. All patients repeated the examination on different days.

Results: : All patients had an afferent pupillary defect in the eye with myelinated nerve fibers. The afferent pupillary defects ranged small to large. Repeated examinations revealed consistent results. The relative afferent pupillary defect seemed to correlate with the area of myelination but not with the final visual acuity.

Conclusions: : Patients with amblyopia associated with myelinated nerve fibers and myopia have afferent pupillary defects in the affected eyes, even in a case of mild amblyopia. The finding supports the notion that this type of amblyopia is a severe form of anisometropic amblyopia that is often resistant to treatment. Nevertheless, because the afferent pupillary defect does not exclude the possibility of visual acuity improvements, amblyopia treatment should be attempted in patients with this syndrome and a relative afferent pupillary defect.

Keywords: amblyopia • pupillary reflex • neuro-ophthalmology: diagnosis