Development of atypical amiodarone keratopathy in a corneal graft

Amiodarone keratopathy and rigid contact lens wear

Two cases are presented of patients wearing rigid gas permeable contact lenses who exhibited the typical fan-shaped patterns of corneal pigment deposition related to long-term medication containing amiodarone. The vortex corneal epitheliopathy and contact lens tolerance were monitored over several years. In both cases, the lens material was replaced with one incorporating an ultra-violet light inhibitor in view of the possibility of medically induced photosensitivity.

Amiodarone Keratopathy

PURPOSE

To evaluate the characteristics and evolution of corneal morphologic changes induced by systemic amiodarone treatment by using in vivo slit scanning confocal microscopy in an attempt to understand the pathogenesis of corneal and other systemic side effects of this drug.

METHODS

Forty-nine eyes of 25 consecutive subjects receiving amiodarone therapy (group A) and 26 eyes of 13 age- and sex-matched healthy control subjects (group B) were enrolled in the study.

RESULTS

In group A, the mean dosage of amiodarone was 224.0 +/- 71.3 mg, and the mean duration of treatment was 21.3 +/- 20.9 months. In eight (8 of 49,16.3) eyes of four patients, no deposition was observed, neither by slitlamp nor by confocal microscopy. The deposition could be detected as early as 2 months after the onset of treatment in 41 (41 of 49, 83.7%) eyes, by slitlamp and confocal microscopy. Deposition was significantly correlated with the duration of treatment and, therefore, the cumulative dose of the drug ingested. Deposits were observed as bright, hyper-reflective spots that were localized intracellularly and were present at the level of basal lamina of all 41 (100%) corneas in which deposition could be observed at confocal microscopy. Deposits were also observed in the superficial epithelium, anterior stroma, mid stroma, and subepithelial nerves in eyes with grade 2 to 4 keratopathy. Additionally, morphologic abnormalities were observed in anterior stromal keratocytes, subepithelial and stromal nerves, and endothelium. The mean anterior and posterior keratocyte densities were statistically significantly higher than those in group B.

CONCLUSIONS

In addition to showing drug deposition does not seem to occur before 2 months of treatment and does not seem to be correlated with tear function. Although the clinical significance of morphologic changes induced by the drug is known and although deposition could not be detected before it was evident with slitlamp biomicroscopy, with some improvement in instrumentation, the authors believe that confocal microscopy will also prove to be useful in early diagnosis and in understanding the pathophysiology of amiodarone keratopathy. This may help grow insight to the mechanism of other, sometimes lethal, systemic side effects of this drug.

Drug-induced corneal complications

PURPOSE OF REVIEW

To review the common corneal manifestations of systemic medications in order to describe the characteristic clinical features associated with particular systemic drugs, the indications for drug cessation, and the risks for irreversible ocular toxicity.

RECENT FINDINGS

Systemic medications may reach the cornea via the tear film, aqueous humor, and limbal vasculature. The corneal changes are often the result of the underlying chemical properties of medications. Amphiphilic medications (amiodarone, chloroquine, suramin, clofazimine, etc.) may produce a drug-induced lipidosis and development of a vortex keratopathy. Antimetabolites (cytarabine) may lead to a degeneration of basal epithelial cells with formation of epithelial microcysts. Additionally, systemically administered medications and drug metabolites may lead to a stromal or endothelial deposition. Corneal changes may result in reduced visual acuity, photophobia, and ocular irritation, though these symptoms typically resolve following drug cessation. Corneal manifestations of systemic medications are often dose related, and may reflect the potential risk for lenticular or retinal changes.

SUMMARY

Corneal changes secondary to systemic medications may affect all layers of the cornea. While corneal deposition is typically not an indication for drug cessation, patients receiving particular medications should be monitored for symptoms related to corneal deposition as well as for signs of irreversible ocular toxicity.

Adverse effects of amiodarone

Amiodarone was introduced 30 years ago as an antianginal agent and subsequently has been used as an antiarrhythmic agent. This drug was initially used for patients with malignant ventricular arrhythmias; however, currently it is being used broadly for rate and rhythm control in patients with atrial fibrillation. At first, amiodarone was primarily used by cardiologists and today it is used throughout the medical profession. Amiodarone therapy can potentially result in a wide range of adverse effects. The majority of these adverse effects are dose related and reversible. The following is a review of the adverse effects and drug interactions of amiodarone along with recommendations for identification and management of these adverse effects.