Plaquenil use above a certain dosage can cause retinal toxicity. Risk factors for Plaquenil retinopathy include a daily dose of greater than 6.5mg/kg (ideal body weight), longer than 10 years of use, liver dysfunction, and kidney dysfunction. Early findings of Plaquenil toxicity include changes in the retinal pigment epithelium of the macula, which can appear similar to early macular degeneration. Both diseases can result in a decrease in visual acuity. It is recommended that patients using long-term Plaquenil be monitored with a dilated eye exam and visual field test every 6 months if they are at high risk, or annually if they are low risk. If any sign of Plaquenil toxicity is noted, the drug should be discontinued in order to prevent progression of the retinopathy.