Clinical and electrophysiology findings in Slovene patients with Leber hereditary optic neuropathy

Abstract

In Leber hereditary optic neuropathy, a reduced N95 component of PERG and severely reduced VEP P100 may be present already in the acute stage of disease, before optic disc pallor appears, suggesting primary dysfunction of retinal ganglion cells.

Functional Changes of Retinal Ganglion Cells and Visual Pathways in Patients with Chronic Leber’s Hereditary Optic Neuropathy during One Year of Follow-up

“…Similar PERG abnormalities, detected in our patients with LHON with 3460/ND1 mutation, were observed by others. 11,12,18,20,21 For the 14484/ND6 mutation, PERG abnormalities found in our present and previous study 12 are in agreement with those observed by others. 20,21 For the PERG abnormalities detected in patients with LHON with 14568/ND6 mutation, the present study represents a original finding because patients with LHON carrying this mutation have not been studied using an electrophysiologic approach.…”

“…This is in contrast with Sharkawi et al, 18 who reported PERG improvement in only 1 case in which PERG was recorded by using similar visual stimuli. For the 14484/ ND6 mutation, we observed PERG improvement in 1 of 13 eyes (7.69%) in contrast to Jarc-Vidmar et al, 20 who reported no PERG changes in the only patient enrolled with this mutation after 30 months of follow-up. In the LHON-14568 patients, we observed a reduction in 60ʹ PERG A in 1 of 4 eyes, whereas by using 15ʹ checks, no eyes showed changes in PERG responses.…”

“…In the group with 3460/ND1 mutation, all eyes showed unmodified VEP responses in agreement with previous reports, 20 whereas Sharkawi et al 18 observed an improvement in only 1 case in which the VEP, found "undetectable" at baseline, became "detectable but delayed" after 18 months of follow-up.…”

“…The VEP abnormalities found in our patients with LHON with 3460/ND1 mutation are consistent with those previously observed in our study 12 and in other studies. 18,20,21 In addition, LHON eyes with 14484/ND6 mutation showed abnormal VEP responses similar to that observed in our previous study 12 and that reported by Jarc-Vidmar et al 20 and Majander et al 21 Eyes with LHON with 14568/ND6 were never studied by electrophysiologic methods, and therefore the detected VEP abnormalities represent an original finding.…”

“…In fact, functional changes have been evaluated by electrophysiologic methods only in few works, reporting isolated cases or in subsets of single mtDNA mutation. [18][19][20][21][22] Therefore, the aim of the present study was to assess, in a large cohort of patients with LHON carrying different mtDNA mutations, possible functional changes in RGCs and their fibers (by PERG recordings) and in visual pathways (by VEP recordings) during 12 months of follow-up in the "chronic phase" of the disease.…”