Purchase this article with an account.
Ana L. Moura, Balázs V. Nagy, Chiara La Morgia, Solange R. Salomao, Adriana Berezovsky, Carlos F. Chicani, Valerio Carelli, Alfredo A. Sadun, Donald C. Hood, Dora F. Ventura; Melanopsin Driven Pupillary Light Response in Leber’s Hereditary Optic Neuropathy (LHON). Invest. Ophthalmol. Vis. Sci. 2011;52(14):5312.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Though there may be massive loss of retinal ganglion cells (RGCs) in Leber’s Hereditary Optic Neuropathy, there is evidence of selective sparing of the 1% of RGCs that express melanopsin (mRGCs). (1,2) To evaluate the physiology of the mRGCs in this optic neuropathy, pupillary light responses (PLRs) were recorded.
12 patients (9 males) with LHON (47.8±14.1 yrs) and 12 healthy subjects (3 males) (38.7±15.9 yrs) were tested. Pupil light responses (PLR) were measured with an eye tracker (Arrington Research Inc.) and the stimuli were controlled with a Ganzfeld system (Roland Consult). Subjects were dark adapted for 10 minutes and pupil responses were measured monocularly, using 1s, 250 cd/m2 flashes. (3) Blue (470 nm) and red (640 nm) flashes were presented at 1 min intervals. The peak amplitude and latency of the transient PLR was measured. To assess the melanopsin-driven PLR (mR), the median amplitude between 4 and 6 s after the offset of the blue flash was measured. (3)
The mR was present in all controls (C) and in 9 of 12 patients, which were subdivided into mR and non-mR groups. No difference was found for transient PLR latencies among the three groups (mR, non-mR, C). Peak amplitudes did not differ between C and mR groups, but the non-mR group differed from both (p<0.05). The mR amplitude was larger for the blue than for the red stimuli, consistent with a sustained response driven by the mRGCs. This response differed among all groups (p< 0.05) for the blue stimulus, being greater in the control group.
The melanopsin-driven PLR is present in LHON patients; although it is diminished in some, it is normal in others. Further tests are needed to investigate a possible relationship of these findings to the relative sparing of mRGCs reported in patients with LHON. (1,2)
This PDF is available to Subscribers Only