Inhibition of critical enzymes & interference with the metabolic functions of retinal pigment epithelium (RPE) & photoreceptors. Both drugs apparently have a selective affinity for melanin, so it gets concentrated in RPE & uveal tissue & is retained for long periods, even after its usage is stopped. Accumulation of pigment laden cells in outer retinal layers 3. What is plaquenil therapy How does plaquenil work for lupus What is plaquenil toxicity Melles RB, Marmor MF. The risk of toxic retinopathy in patients on long-term hydroxychloroquine therapy. JAMA Ophthalmol 2014;153–60. Wolfe F, Marmor MF Rates and predictors of hydroxychloroquine retinal toxicity in patients with rheumatoid arthritis and systemic lupus erythematosus. Arthritis Care Res Hoboken 2010, 626775-784. Chloroquine retinopathy, is a form of toxic retinopathy damage of the retina caused by the drugs chloroquine or hydroxychloroquine, which are sometimes used in the treatment of autoimmune disorders such as rheumatoid arthritis and systemic lupus erythematosus. This eye toxicity limits long-term use of the drugs. Retinal photograph showing classic “bull’s eye” retinopathy of hydroxychloroquine toxicity, which represents atrophy of the retinal pigment epithelium. This is a relatively late change, and good screening can detect toxicity before any bull’s eye is visible. Symptoms: can be asymptomatic Earliest symptoms - difficulty in reading/ fine tasks due to central / paracentral scotomas Gradually these enlarge & involve fixation, reducing visual acuity later. The earliest histopathologic change, even before RPE damage, appears to be membranous cytoplasmic bodies in ganglion cells and degenerative changes in photoreceptor outer segments. Damage & reduction of photoreceptors It increases with daily dose & duration & varies from 1-28% without any predilection for any particular age, sex or race. Hydroxychloroquine toxic retinopathy Hydroxychloroquine retinopathy — implications of research., Chloroquine retinopathy - Wikipedia Deschloroquine used on chloroquine resistant parasites Hydroxychloroquine can cause irreversible retinal toxicity, resulting in bilateral bull’s eye retinopathy, but is regarded as less toxic to the retina than chloroquine and it does not cause the corneal deposits seen with chloroquine therapy. Hydroxychloroquine DermNet NZ. Hydroxychloroquine Retinopathy Still Alive and Well - The.. Hydroxychloroquine-related retinal toxicity Rheumatology.. However, Hydroxychloroquine and chloroquine CQ have been associated with irreversible visual loss due to retinal toxicity. Hydroxychloroquine retinal toxicity is far more common than previously. Chloroquine and Hydroxychloroquine. Chloroquine and its derivative, hydroxychloroquine sulfate, which have been useful in treating malaria and in larger doses, collagen-vascular disease, cause a cumulative dose-related pigmentary retinopathy. Hydroxychloroquine Retinopathy. Chloroquine retinopathy was described for the first time in the early ’60s. Hydroxychloroquine and chloroquine work in a similar way as antimalarial medication with different therapeutic and toxic doses and produce a similar pattern of retinopathy.