[Adverse ocular drug reactions of systemic antimicrobial agents]

Antimicrobial therapy can cause adverse ocular drug reactions. They are most often noticed by changes of the eyes' anterior segments or by pain and visual disturbances. It is important that physicians but also patients are watchful for the symptoms and know about their potential dangerous consequences because the chance for reversibility may depend on their early detection. During therapy with voriconazol about one third of patients complain of visual disturbances soon after the first doses but symptoms generally resolve after a short period of time without sequelae. Telithromycin may impair accommodation due to its anticholinergic activity. Neuropathies of the optic nerve may be caused by ethambutol, isoniazid, streptomycin, and linezolid. The first symptoms, such as disturbances in colour vision, typically occur with a latency of several weeks after start of therapy. This adverse effect may result in serious long term impairment of visual function. Toxic effects on the mitochondria in retinal ganglion cells are discussed as underlying mechanisms. Rifabutin and cidofovir may cause intraocular inflammatory reactions. In addition cidofovir may induce a pronounced reduction of the ocular pressure. Adverse drug reactions are often dose dependent and therefore influenced by impaired kidney or liver function, pharmacogenetics, or by drug-drug interactions. Potential serious drug induced ocular side effects require close cooperation with an ophthalmologist for evaluation of the individual risk benefit ratio, if possible, even before beginning of antimicrobial therapy.