These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: The Photopic Negative Response: An Objective Measure of Retinal Ganglion Cell Function in Patients With Leber's Hereditary Optic Neuropathy. Author: Karanjia R, Berezovsky A, Sacai PY, Cavascan NN, Liu HY, Nazarali S, Moraes-Filho MN, Anderson K, Tran JS, Watanabe SE, Moraes MN, Sadun F, DeNegri AM, Barboni P, do Val Ferreira Ramos C, La Morgia C, Carelli V, Belfort R, Coupland SG, Salomao SR, Sadun AA. Journal: Invest Ophthalmol Vis Sci; 2017 May 01; 58(6):BIO300-BIO306. PubMed ID: 29049835. Abstract: PURPOSE: The photopic negative response (PhNR) is a slow negative component of a flash photopic full-field ERG that has been shown to be specific for retinal ganglion cell (RGC) activity. Direct evaluation of RGC function is desirable in patients with Leber's hereditary optic neuropathy (LHON) in which the loss of central acuity can make it difficult to monitor patients with standard metrics. The purpose of this study was to evaluate the use of PhNR as an objective noninvasive clinical metric in LHON. METHODS: Full-field photopic ERG recordings were collected in subjects with the mt.11778G>A/ND4 LHON mutation using a red on blue stimulus. The PhNR was identified using a computer-based automated detection system, and data were manually examined to remove movement artifacts. RESULTS: The PhNR amplitude was compared between controls (n = 13), carriers (n = 17), and affected (n = 6). Mean PhNR amplitude decreased significantly across groups (P < 0.0001). Post hoc Tukey's test revealed a significant decrease in PhNR amplitude between carriers and controls (P < 0.05) and between carriers and affected (P < 0.01). CONCLUSIONS: We are able to demonstrate that the PhNR amplitude is significantly decreased in patients affected by LHON compared to carriers in a well-described pedigree. Surprisingly, there was also a decrease in PhNR in carriers, suggesting potential subclinical RGC dysfunction in some carriers. This is important in patients affected with LHON who typically have a dense central scotoma. The PhNR may be a useful objective outcome measure for future clinical trials.[Abstract] [Full Text] [Related] [New Search]