Clinical evaluation of amiodarone induced ocular toxicity in cardiac patients

ABSTRACT

Amiodarone is a highly effective treatment in various cardiac arrhythmias however, with number of side effects. Recent studies and case reports found that chronic treatment with amiodarone can induce toxic changes in different parts of the eye. The aim of this work is to study ocular toxic manifestations induced by chronic administration of amiodarone in cardiac patients, its consequence on eyesight, and its correlation with the dose and the duration of treatment, by measuring visual acuity, visual field assessment, slit lamp and fundoscopic examinations. Control group [group I] was 12 healthy volunteers. Twenty four cardiac patients on amiodarone therapy were classified into 2 groups, group II receiving oral dose of amiodarone 200 mg/d, group III receiving oral dose of amiodarone 400mg/d, for less than 1 month. All patients were submitted to ophthalmic examination every 3 months for 12 months. It was found that amiodarone [200 mg/d] after 3 months did not induce ocular changes. After 6 months, bilateral corneal deposits of grade 1 and 2 were noticed in 58.3% of patients. After 9 months, 75.0% of patients showed corneal lesions of grade 3. At the 12[th] month, 83.3% of patients were affected, with a non significant difference between the mean values of visual acuity as compared with the control group [P>0.05], normal visual field and absence of retinal toxic changes all through the study. 66.6% of patients received amiodarone [400 mg/d] had bilateral corneal deposits of grade 1 and 2, after 3 months. After 6 months, 91.6% of patients were affected. At the 9th month, 100% of patients had vortex verticillata of grade 3. At the 12[th] month, keratopathy of grade 3 and 4 was obviously detected in all patients [100%]. Regarding visual acuity, after 6 months of amiodarone administration, 2 patients had mild diminution of vision and visual field defect. Fundus examination revealed toxic retinopathy in the both patients. After 12 months, bilateral optic disc swelling was noticed in one patient and necessitated discontinuation of the drug. Follow up of those patients after discontinuation of amiodarone, showed slight improvement after 3 months. After 6 months, visual fields showed significant improvement with normal optic disc in one patient. The other patient showed complete resolution of the left optic disc swelling with minimal swelling in the right one. It was concluded that chronic administration of amiodarone induces reversible ocular toxic changes including retina and optic disc, can be detected at the first 3 months of therapy, increase by the dose and the duration of treatment that may necessitate discontinuation of the drug. Periodic ophthalmic examination is a valuable measure for early detection of ocular toxicity