TY - JOUR
T1 - The Pupil light reflex in leber's hereditary optic neuropathy
T2 - Evidence for preservation of melanopsin- expressing retinal ganglion cells
AU - Moura, Ana Laura A
AU - Nagy, Balázs V.
AU - la Morgia, Chiara
AU - Barboni, Piero
AU - Oliveira, André Gustavo Fernandes
AU - Salomaõ, Solange R.
AU - Berezovsky, Adriana
AU - de Moraes-Filho, Milton Nunes
AU - Chicani, Carlos Filipe
AU - Belfort, Rubens
AU - Carelli, Valerio
AU - Sadun, Alfredo A.
AU - Hood, Donald C.
AU - Ventura, Dora Fix
PY - 2013/6/4
Y1 - 2013/6/4
N2 - Purpose. To investigate the pupillary light reflex (PLR) of patients with severe loss of vision due to Leber's Hereditary Optic Neuropathy (LHON) in the context of a proposed preservation of melanopsin-expressing retinal ganglion cells (mRGCs). Methods. Ten LHON patients (7 males; 51.6 ± 14.1 years), with visual acuities ranging from 20/400 to hand motion perception and severe visual field losses, were tested and compared with 16 healthy subjects (7 males; 42.15 ± 15.4 years) tested as controls. PLR was measured with an eye tracker and the stimuli were controlled with a Ganzfeld system. Pupil responses were measured monocularly, to 1 second of blue (470 nm) and red (640 nm) flashes with 1, 10, 100, and 250 cd/m2 luminances. The normalized amplitude of peak of the transient PLR and the amplitude of the sustained PLR at 6 seconds after the flash offset were measured. In addition, optical coherence topography (OCT) scans of the peripapillary retinal nerve fiber layer were obtained. Results. The patient's peak PLR responses were on average 15% smaller than controls (P <0.05), but 5 out of 10 patients had amplitudes within the range of controls. The patients' sustained PLRs were comparable with controls at lower flash intensities, but on average, 27% smaller to the 250 cd/m2 blue light, although there was considerable overlap with the PLR amplitudes of control. All patients had severe visual field losses and the retinal nerve fiber layer thickness was reduced to a minimum around the optic disc in 8 of the 10 patients. Conclusions. The PLR is maintained overall in LHON patients despite the severity of optic atrophy. These results are consistent with previous evidence of selective preservation of mRGCs.
AB - Purpose. To investigate the pupillary light reflex (PLR) of patients with severe loss of vision due to Leber's Hereditary Optic Neuropathy (LHON) in the context of a proposed preservation of melanopsin-expressing retinal ganglion cells (mRGCs). Methods. Ten LHON patients (7 males; 51.6 ± 14.1 years), with visual acuities ranging from 20/400 to hand motion perception and severe visual field losses, were tested and compared with 16 healthy subjects (7 males; 42.15 ± 15.4 years) tested as controls. PLR was measured with an eye tracker and the stimuli were controlled with a Ganzfeld system. Pupil responses were measured monocularly, to 1 second of blue (470 nm) and red (640 nm) flashes with 1, 10, 100, and 250 cd/m2 luminances. The normalized amplitude of peak of the transient PLR and the amplitude of the sustained PLR at 6 seconds after the flash offset were measured. In addition, optical coherence topography (OCT) scans of the peripapillary retinal nerve fiber layer were obtained. Results. The patient's peak PLR responses were on average 15% smaller than controls (P <0.05), but 5 out of 10 patients had amplitudes within the range of controls. The patients' sustained PLRs were comparable with controls at lower flash intensities, but on average, 27% smaller to the 250 cd/m2 blue light, although there was considerable overlap with the PLR amplitudes of control. All patients had severe visual field losses and the retinal nerve fiber layer thickness was reduced to a minimum around the optic disc in 8 of the 10 patients. Conclusions. The PLR is maintained overall in LHON patients despite the severity of optic atrophy. These results are consistent with previous evidence of selective preservation of mRGCs.
KW - Ganglion cells
KW - LHON
KW - Melanopsin
KW - OCT
KW - Pupillometry
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U2 - 10.1167/iovs.12-11137
DO - 10.1167/iovs.12-11137
M3 - Article
C2 - 23737476
AN - SCOPUS:84879626121
VL - 54
SP - 4471
EP - 4477
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
SN - 0146-0404
IS - 7
ER -