Association of optic disc size with development and prognosis of Leber's hereditary optic neuropathy.
OBJECTIVE
To study the optic nerve head (ONH) morphology of patients with Leber's hereditary optic neuropathy (LHON) in a large family from Brazil carrying the 11778/ND4 mutation and in a case series of unrelated Italian families bearing different mitochondrial DNA (mtDNA) pathogenic mutations.


METHODS
Enrolled in the study were 15 LHON-affected patients (LHON-affected) and 45 LHON unaffected mutation carriers (LHON carriers) belonging to the previously reported Brazilian SOA-BR LHON pedigree and 56 LHON-affected and 101 LHON carriers from 45 unrelated LHON Italian pedigrees molecularly defined. The LHON-affected were subgrouped according to the extent of visual recovery. All individuals underwent optic nerve head (ONH) analysis by optical coherence tomography.


RESULTS
In the Brazilian sample, the mean optic disc area was significantly larger in LHON carriers than in the control group (P=0.002). In the Italian sample, the mean optic disc area and vertical disc diameter were significantly higher in LHON carriers than in both LHON-affected (respectively, P=0.008 and P<0.001) and control subjects (P<0.001 in both cases). The LHON-affected with visual recovery had a significantly larger vertical disc diameter when compared with those without visual recovery (P=0.03).


CONCLUSIONS
The results, revealing that the ONH size is larger in LHON carriers than in LHON-affected, suggest a protective role for this anatomic trait. Such a hypothesis is reinforced by the observation that, among the LHON-affected, larger discs correlated with visual recovery and better visual outcome. The findings may be relevant for prognosis and provide a mechanism for identifying nuclear-modifying genes implicated in the variability of penetrance in LHON.
Ramos
Carolina do V F
Cdo V
Department of Ophthalmology, Federal University of São Paulo (UNIFESP), São Paulo, Brazil.
Bellusci
Costantino
C
Savini
Giacomo
G
Carbonelli
Michele
M
Berezovsky
Adriana
A
Tamaki
Celina
C
Cinoto
Rafael
R
Sacai
Paula Y
PY
Moraes-Filho
Milton N
MN
Miura
Hevillin M P P
HM
Valentino
Maria Lucia
ML
Iommarini
Luisa
L
De Negri
Anna Maria
AM
Sadun
Federico
F
Cortelli
Pietro
P
Montagna
Pasquale
P
Salomao
Solange R
SR
Sadun
Alfredo A
AA
Carelli
Valerio
V
Barboni
Piero
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics; D018450:Disease Progression; D005260:Female; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D029242:Optic Atrophy, Hereditary, Leber / Q000175:diagnosis* / Q000235:genetics; D009898:Optic Disk / Q000473:pathology*; D010375:Pedigree; D019683:Penetrance; D011379:Prognosis; D041623:Tomography, Optical Coherence
D004272:DNA, Mitochondrial