Purchase this article with an account.
S.R. Salomao, V. Carelli, P.Y. Sacai, A. Berezovsky, R.E. Andrade, C.F. Chicani, J.M. Pereira, M.N. Moraes, R. Belfort Jr, A.A. Sadun; Pattern-Reversal Visually Evoked Potential (VEP) in Asymptomatic Carriers From an Extensive Brazilian Pedigree With 11778 Leber’s Hereditary Optic Neuropathy (LHON) . Invest. Ophthalmol. Vis. Sci. 2003;44(13):936.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: LHON is a maternally inherited disease, associated with mitochondrial DNA point mutations and characterized by profound bilateral loss of central vision. Only a small percentage of a pedigree become affected. This study investigated possible subclinical abnormalities in pattern-reversal VEP (PRVEP) in asymptomatic maternally and non-maternally related members from an extensive Brazilian 11778 LHON pedigree. Methods: Transient PRVEP (reversal rate = 2Hz; checkerboard stimuli 15’ and 60’; 100% contrast) was monocularly recorded in 93 asymptomatic members, aging from 5-69 years, from a large Brazilian 11778 pedigree. All participants had best corrected visual acuity of 20/20 in each eye and were divided into three categories: carriers (n=46); descendants of affected males (n=35) and descendants of non-affected males (n=12). An additional control group of 21 off pedigree members (spouses) with 20/20 monocular acuity was also tested. Latency for N75, P100 and N135 peaks and P100 amplitude were determined for both stimuli. Temporal dispersion of the response was calculated by the difference in latency between N135 and N75. Kruskal-Wallis one-way analysis of variance on ranks, followed by Dunn’s test was used to compare the four groups. Results: Statistically prolonged latencies were found in the carriers when compared to controls with stimulus size 15’ for P100 (H=7.916; P=0.048) and N135 (H=20.157; P<0.001), as well as with stimulus size 60’ for N135 (H=18.202; P<0.001). Latencies for N75 component were statistically prolonged in the descendants of affected males when compared to descendants of non-affected males for 60’ stimulus (H=10.026; P=0.018). Widened response was found in carriers when compared to controls and descendants of affected males (H=23.127; P<0.001). The amplitude was comparable in the four studied groups. Conclusions: In this large 11778 LHON pedigree we found consistently prolonged latencies in PRVEP in asymptomatic carriers. Since visual acuity was normal in all participants, these abnormalities could be considered as subclinical features of those carrying the mutation. Follow-up studies will clarify the correlation of pattern-reversal VEP with other subtle abnormalities in patients at genetic risk to develop the disease.
This PDF is available to Subscribers Only