Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv für klinische und experimentelle Ophthalmologie
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Graefes Arch. Clin. Exp. Ophthalmol. · May 2005
Optical coherence tomography can measure axonal loss in patients with ethambutol-induced optic neuropathy.
To map and identify the pattern, in vivo, of axonal degeneration in ethambutol-induced optic neuropathy using optical coherence tomography (OCT). Ethambutol is an antimycobacterial agent often used to treat tuberculosis. A serious complication of ethambutol is an optic neuropathy that impairs visual acuity, contrast sensitivity, and color vision. However, early on, when the toxic optic neuropathy is mild and partly reversible, the funduscopic findings are often subtle and easy to miss. ⋯ The OCT results in these patients with EMB-induced optic neuropathy show considerable loss especially of the temporal fibers. This is consistent with prior histopathological studies that show predominant loss of parvo-cellular axons (or small-caliber axons) within the papillo-macular bundle in toxic or hereditary optic neuropathies. OCT can be a valuable tool in the quantitative analysis of optic neuropathies. Additionally, in terms of management of EMB-induced optic neuropathy, it is important to properly manage ethambutol dosing in patients with renal impairment and to achieve proper transition to a maintenance dose once an appropriate loading dose has been reached.