Abstract
Abstract: :
Purpose: To investigate in follow-up examination, using epidemiological, neuro-ophthalmological and psychophysical testing, on a previously described very large pedigree with Leber's Hereditary Optic Neuropathy (LHON). Methods: Last year we described a 300 member 11778 , J-haplogroup mtDNA molecular analyzed pedigree located in an area of rural Brazil. Our international field investigation team returned one year later for comprehensive follow-up examinations. We also performed more extensive psychophysical testing including F-M 100 color testing, electrophysiology and GDx quantitative nerve fiber layer analysis. Over 300 patients were contacted and over 200 re-examined. Results: Many of the LHON-Carriers demonstrated subtle but consistent impairments. In particular, we regularly found mild sectoral optic disc edema, blood vessel telangectasis, arcuate nerve fiber layer edema, mild arcuate visual field deficits, Tritan-axis dyschromatopsia, mild losses of high spatial frequency contrast sensitivity and GDx nerve fiber layer losses in the arcuate bundles. Each of these findings correlated well with the others. Comparison with examinations in the previous year demonstrated some new findings but also some reversals of impairments from before. For example, the areas of optic disc edema and telangectasis and the corresponding visual field deficits shifted. In LHON-Affected, there was further deterioration of visual acuity and evidence of progression as manifested by fundus and psychophysical findings. Conclusions: Contrary to conventional wisdom, LHON is not simply an apoplectic event followed by a stable condition. Carriers have subtle chronic and potentially reversible clinical findings and those with severe visual loss (so-called Affected) continue to demonstrate low-grade deterioration that is corroborated by post-mortem ultrastructural studies.
Keywords: neuro-ophthalmology: optic nerve • mitochondria • optic disc