Evaluation of retinal nerve fiber layer thickness in a patient with bilateral optic disc drusen

Abstract

Optic disc drusen (ODD) is the accumulations of calcified hyaline-like material within the substance of the optic nerve head. Optic disc drusen, especially if it is bilateral, may mimic the clinical presentation of papilledema. Usually retinal nerve fiber layer (RNFL) thinning can be present in ODD. In this report we present uncommon RNFL changes in a patient with bilateral ODD. A 17-year-old male was referred by another center with a diagnosis of optic disc edema. The patient's visual acuity, the slit-lamp examination and the intraocular pressures were normal in both eyes. On fundus examination, there were irregularly elevated discs bilaterally and the optic nerves appear with hazy disk margins. He did not have visual field defects in automated perimetry. Bilateral ODD were identified and confirmed by B-scan ultrasonography and optical coherence tomography (OCT) demonstrated 4 clock hours of RNFL thickening. Optic disc drusen may be misdiagnosed as papilledema. Thus, clinical suspicion of ODD is important in order to diagnose papilledema and prevents unnecessary interventions. Although most of eyes with ODD have normal or thinner RNFL thickness, some of these eyes can have thicker RNFL thickness.