She suffered from Sjogren syndrome and inflammatory arthritis and was currently treated with prednisone and methotrexate. She was previously treated with hydroxychloroquine (Plaquenil) 200mg bid (6.5mg/kg) for 10 years, which was stopped one year prior to presentation. Plaquenil and muscle relaxor P falciparum resistance to chloroquine Where can i get hydroxychloroquine cheapest Hydroxychloroquine effect on platelets And quantified using ERG. Which type of ERG to apply depends on the mechanism and site of retinal toxic-ity. Identifying retinal toxicity due to chloroquine or hydroxychloroquine is a pertinent application of mfERG. SIGNS OF TOXICITY Plaquenil toxicity first affects small areas of the retina between 5° and 15° from the fovea. Figures 2 and 3 show Determination of hydroxychloroquine toxicity Plaquenil toxicity. In general, an abnormal mfERG indicates that the foveal cones and/or bipolar cell layers are dysfunctional and the source of vision loss. Unlike the focal ERG, mfERG also indicates the precise distribution of the retinal dysfunction. Although the exact mechanism by which chloroquine CQ and hydroxychloroquine HCQ - commonly known as Plaquenil induce retinal toxicity is not well understood, but it is recognized as a serious ophthalmologic concern because it is not treatable. 1 Guidelines from the American Academy of Ophthalmology AAO on screening for CQ and HCQ toxicity recommend that all patients starting therapy receive a baseline screening followed by annual follow-up visits beginning at 5 years after the start. Review of systems: Blurred vision, halos, dry eye, dry mouth, gastroesophageal reflux, joint pain Pupils: Reactive to light in each eye from 5 mm in the dark to 2 mm in the light. Extraocular movements: Full, both eyes (OU) Confrontation visual fields: Full OU Intra-ocular pressure The optic nerves appeared healthy with a 0.3 cup-to-disc ratio. Past Ocular History: None Medical History: Sjogren syndrome and inflammatory arthritis, supraventricular tachycardia, anxiety, depression, peptic ulcer disease Medications: prednisone, methotrexate, amitriptyline, ranitidine, estradiol, tizanidine, diltiazem, Restasis Allergies: codeine, droperidol Family History: heart disease, arthritis, cancer Social History: occasional alcohol but no tobacco or intravenous drug use. Multifocal erg plaquenil toxicity Hydroxychloroquine Plaquenil Toxicity and., Multifocal ERG in Practice - Maculopathy with plaquenilPlaquenil avisHydroxychloroquine side effects retinopathy Multifocal electroretinography mfERG is highly sensitive for detecting hydroxychloroquine retinal toxicity. • Ring 2 P1 amplitude is the most sensitive mfERG parameter to detect hydroxychloroquine retinal toxicity. • Ring 2 P1 amplitude is inversely related to cumulative and daily doses of hydroxychloroquine. • The Diagnostic Utility of Multifocal Electroretinography.. This is Why You Need Multifocal ERG if You Have Plaquenil.. Electroretinography ERG, Multi-focal Electroretinography.. Purpose To evaluate the utility of ring ratios in detecting hydroxychloroquine HCQ related retinal toxicity using the 103-hexagon multifocal electroretinogram mfERG. Design Retrospective cross-sectional study. Methods 23 patients taking HCQ were consecutively evaluated for retinal toxicity and divided into those without HCQ-non-toxic group and with documented visual field loss HCQ-toxic. Multifocal ERG has the potential to be used as an early screening device for patients taking high doses of hydroxychloroquine before they become symptomatic or show clinical signs of toxicity. Because stabilization and perhaps reversibility are more likely if retinopathy is detected early, the development of multifocal ERG for detection of the earliest stages of hydroxychloroquine retinopathy is paramount. 15 Multimodal Imaging in Plaquenil Toxicity. Conversely, multifocal ERG, with its ability to record localized central retinal defects, has gained acceptance as an excellent candidate for detecting subtle changes in the early stages of toxicity. 20 Raj Maturi, MD.