Linezolid-induced optic neuropathy

Abstract

Many systemic antimicrobials have been implicated to cause ocular adverse effects. This is especially relevant in multidrug therapy where more than one drug can cause a similar ocular adverse effect. We describe a case of progressive loss of vision associated with linezolid therapy. A 45-year-old male patient who was on treatment with multiple second-line anti-tuberculous drugs including linezolid and ethambutol for extensively drug-resistant tuberculosis (XDR-TB) presented to us with painless progressive loss of vision in both eyes. Color vision was defective and fundus examination revealed optic disc edema in both eyes. Ethambutol-induced toxic optic neuropathy was suspected and tablet ethambutol was withdrawn. Deterioration of vision occurred despite withdrawal of ethambutol. Discontinuation of linezolid resulted in marked improvement of vision. Our report emphasizes the need for monitoring of visual function in patients on long-term linezolid treatment.

Figure 1

Fundus photograph showing disc edema in right eye

Figure 2

Fundus photograph showing disc edema in left eye

Figure 3

Visual field showing peripheral constriction and superotemporal quadrantanopia in right eye

Figure 4

Visual field left eye showing quadrantanopia (low reliability)

Figure 5

Stratus OCT showing increase in retinal nerve fiber layer thickness involving superior and inferior quadrants in right eye and superior, inferior, and nasal quadrants in left eye (arrows)

Figure 6

Fundus photograph showing resolved disc edema with temporal pallor of optic disc in right eye

Figure 7

Fundus photograph left eye showing temporal pallor of optic disc

Figure 8a

Follow-up visual field after discontinuation of linezolid showing partial recovery in right eye

Figure 8b

Follow-up visual field in left eye after discontinuation of linezolid

Figure 9

Stratus OCT showing reduction in retinal nerve fiber layer edema in both eyes