Impairment of colour vision associated with amiodarone keratopathy.

Objective changes in colour vision have not been demonstrated previously in patients on long-term amiodarone therapy, although the occurrence of blurring of vision and seeing coloured haloes around lights has been widely reported. In a masked study, colour vision was assessed in 15 patients who had been treated with amiodarone for 16-72 months. Subjects with extensive corneal microdeposits (Miller stage 3) had worse colour vision than subjects with mild or moderate corneal changes (Miller stages 1 and 2) (P = 0.02), and higher serum concentrations of the metabolite desethlyamiodarone (P = 0.008). The only subject with marked asymmetry of corneal changes had a long-standing unilateral ptosis, suggesting that exposure to light might influence the development of corneal changes.