Alex Melamud

Ocular Ethambutol Toxicity

Ethambutol is an antimicrobial agent used frequently to treat tuberculosis. The most commonly recognized toxic effect of ethambutol is optic neuropathy, which generally is considered uncommon and reversible in medical literature. We describe a 43-year-old man who developed signs and symptoms of bilateral optic neuropathy during treatment with ethambutol. This case and a review of the literature show the severe and unpredictable nature of ethambutol toxicity and its potential for irreversible vision loss despite careful ophthalmologic monitoring.

Color vision testing

The science of color vision testing has evolved since its inception in the late 1700s. Since then, the rudimentary technique of comparing color names has been replaced by more sophisticated methods. Commonly used tests in clinical practice today include isochromatic plates, arrangement tests, anomaloscopes, and lantern tests. Each category has unique attributes that make it suitable for a particular clinical situation. The clinician should be aware of the requirements for administering and grading each test type. Factors such as the quality of the illuminant and the size of the field of view are important elements in setting up a proper color vision laboratory. Currently, no treatment exists for congenital color vision defects. However, studies show that diagnosis of these defects early in life may help children adjust better to tasks at school and may help adults understand their limitations at work. Acquired color vision defects are often used as markers of ocular pathology in the clinical setting. Different color vision tests are appropriate for diagnosing the different categories of defects. Sometimes, a battery of tests may be appropriate. This paper is a review of the current knowledge in the field of color vision testing.