Drug-related mitochondrial optic neuropathies

Area of Science:

• Ophthalmology
• Neuroscience
• Pharmacology

Background:

• Optic neuropathies, both genetic and acquired, often present with similar symptoms affecting the papillomacular bundle (PMB).
• PMB fibers are particularly vulnerable due to their small size, lack of myelination, and high energy requirements.
• A common underlying factor in these conditions is presumed mitochondrial dysfunction.

Purpose of the Study:

• To review the evidence linking various medications to mitochondrial optic neuropathy (MON).
• To highlight the differential diagnosis of MON, distinguishing it from other causes of bilateral visual loss.
• To emphasize the importance of recognizing drug-induced MON for timely intervention.

Main Methods:

• Literature review of medications implicated in mitochondrial optic neuropathy.
• Analysis of evidence strength connecting specific drugs to MON.
• Comparison of MON symptoms with other optic nerve disorders.

Main Results:

• Several drugs, including ethambutol, chloramphenicol, linezolid, erythromycin, streptomycin, and antiretrovirals, are identified as potential causes of drug-related MON.
• The severity of drug toxicity is often related to dosage and duration of treatment.
• Discontinuation of the offending drug can lead to substantial visual improvement if managed promptly.

Conclusions:

• Mitochondrial optic neuropathies represent a spectrum of disorders converging on mitochondrial dysfunction.
• Clinicians must maintain awareness of drugs capable of inducing MON.
• Prompt diagnosis and drug cessation are vital to prevent permanent vision impairment.