Functional Loss of the Inner Retina in Childhood Optic Gliomas Detected by Photopic Negative Response.

Abstract

PURPOSE:

To determine whether the Ganzfeld ERG photopic negative response (PhNR), an assay of inner retinal activity, is altered in childhood optic glioma (OPG).

METHODS:

Seventeen pediatric patients with a diagnosis of OPG, established on neuro-ophthalmologic and brain/orbit magnetic resonance imaging (MRI) criteria, were enrolled. The examination protocol included determination of visual acuity (VA), fundus examination, retinal nerve fiber layer (RNFL) measurement with spectral-domain optical coherence tomography (SD-OCT) and photopic ERG. Fifteen normal children served as control group. Ten of the 17 OPG patients were retested 1 to 3 months after the first examination. Photopic ERGs were recorded after 10 minutes of light adaptation in response to a Ganzfeld flash presented on a steady light-adapting background. Amplitude and peak-time of b-wave and PhNR were measured.

RESULTS:

Compared with normal values, PhNR amplitude was significantly reduced (P < 0.0001) in the OPG group. Peak-time of PhNR as well as b-wave amplitude and peak-time were similar in both patients and controls. Losses of PhNR were found in patients with involvement of either anterior or retro-chiasmatic optic pathways. Linear regression analysis showed significant positive correlation between RNFL thickness and PhNR amplitude (r2 = 0.34, P = 0.008). Mean percentage test-retest difference for PhNR amplitude and peak-time was 12% and 6%, respectively.

CONCLUSIONS:

These findings indicate that flash ERG PhNR can detect a loss of inner retinal function in childhood OPGs supporting the use of this technique, as an adjunct to standard psychophysical and electrophysiological tests, to monitor visual function in OPG.

• Authors: Edoardo Abed, Marco Piccardi, Daniela Rizzo, Antonio Chiaretti, Lucia Ambrosio, Sergio Petroni, Rosa Parrilla, Anna Dickmann, Riccardo Riccardi, Benedetto Falsini
• Journal: Investigative ophthalmology & visual science (Invest Ophthalmol Vis Sci) Vol. 56 Issue 4 Pg. 2469-74 (Apr 2015) ISSN: 1552-5783 [Electronic] United States
• PMID: 25634980 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Adaptation, Ocular (physiology)
• Adolescent
• Child
• Child, Preschool
• Color Vision (physiology)
• Electroretinography
• Female
• Humans
• Male
• Optic Nerve Glioma (diagnosis, physiopathology)
• Photic Stimulation (methods)
• Retinal Ganglion Cells (physiology)
• Tomography, Optical Coherence
• Visual Acuity
• Visual Fields