Amiodarone keratopathy. Correlation to dosage and duration

Area of Science:

• Ophthalmology
• Cardiology
• Pharmacology

Background:

• Amiodarone hydrochloride, a benzofurane derivative, is a widely used antiarrhythmic medication.
• This drug is associated with a specific ocular side effect known as verticillate epithelial keratopathy.
• The keratopathy has been previously classified into three distinct stages.

Purpose of the Study:

• To investigate the relationship between amiodarone hydrochloride dosage and duration of treatment with the progression of verticillate epithelial keratopathy.
• To characterize the stages of keratopathy in relation to patient treatment regimens.
• To determine the reversibility of amiodarone-induced keratopathy.

Main Methods:

• Retrospective analysis of patient data undergoing amiodarone hydrochloride treatment.
• Classification of verticillate epithelial keratopathy into three stages based on clinical examination.
• Correlation of observed keratopathy stages with daily dosage and treatment duration of amiodarone hydrochloride.

Main Results:

• Low daily dosages (100-200 mg) of amiodarone hydrochloride were associated with clear corneas or Stage 1 keratopathy, irrespective of treatment duration.
• Higher daily dosages (400-1,400 mg) correlated with Stage 2 and 3 keratopathy, with progression dependent on treatment duration.
• Keratopathy showed progression even with dosage reduction, but complete regression was observed after medication discontinuation.

Conclusions:

• Amiodarone hydrochloride dosage and treatment duration are critical factors in the development and severity of verticillate epithelial keratopathy.
• The ocular side effects of amiodarone hydrochloride are dose-dependent and reversible upon cessation of the drug.
• Ophthalmologists should monitor patients on amiodarone hydrochloride for this specific corneal toxicity.