Evaluation of the Visual Toxicity of Drugs

Abstract

We evaluated a short-term test method for retinal toxicity induced by chloroqine in rabbits. We injected 2 and 4 mg/eye chloroquine intravitreally into one eye of albino and pigmented rabbits (test eye), and saline into other (control eye). After the treatment, we examined the retinal toxicity of the test substance by electroretinogram (ERG; the a-, b- and c-waves and the oscillatory potentials). The ERG of both eyes was recorded periodically at the same time for four weeks and compared between test and control eyes.

Intravitreal injection of chloroquine caused clear by diminished amplitude and prolongated latency of the b-wave and oscillatory potentials, in both types of rabbit and at both dosages. The results indicated that chloroquine has retinal toxicity. With our method, the retinal toxicity of chloroquine in rabbits can be evaluated quickly by intravitreal injection and electrophysiological recording (ERG). We think that our method is useful for evaluating the retinal toxicity of chemical substances which have affinity for melanine and pass easily into the eyeball.