Relative post-mortem sparing of afferent pupil fibers in a patient with 3460 Leber's hereditary optic neuropathy

Swaraj Bose, Navneet Dhillon, Fred N. Ross-Cisneros, Valerio Carelli

Research output: Contribution to journalArticle

Abstract

Background: Relative sparing of the pupillary reflexes in patients with leber's hereditary optic neuropathy (LHON) has been observed clinically. This study sought to test histologically whether retino-pupillary fibers are spared in LHON. Methods: Di-I, a fluorescein dye that allows anterograde labeling of axons, was injected into the brachium of the superior colliculus in post-mortem brain from a patient diagnosed with LHON (3460 mutation) and a normal control brain. After 4 weeks, serial fragmatome sections were obtained in the pretectal area and further stained with propidium iodide (PI stains DNA) to delineate the pretectal nuclei in the dorsal midbrain. Examination was performed under a confocal microscope. Optic nerves obtained from the above subjects were cut, mounted and stained with p-phenylenediamine (PPD) and trichrome stain for digital morphometry. Results: Di-I-labeled fibers were visible on all sections from the superior colliculus to the pretectum in the LHON and the control specimens, as were the nuclei in the cell bodies stained with PI. There was mild attenuation of the afferent pretectal fibers in LHON, but this was not as dramatic as the attenuation of the total population of fibers in the LHON optic nerve. Conclusions: In our LHON patient, the preservation of retinofugal fibers to the pretectum lends support to the clinical observation of relatively preserved pupillary function in LHON.

Original languageEnglish
Pages (from-to)1175-1179
Number of pages5
JournalGraefe's Archive for Clinical and Experimental Ophthalmology
Volume243
Issue number11
DOIs
Publication statusPublished - Nov 2005

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Keywords

  • Di-I tract tracing
  • LHON
  • Pretectal nucleus
  • Pupillary pathway

ASJC Scopus subject areas

  • Ophthalmology

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