Low hydroxychloroquine blood levels in patients who have had gastric bypass surgery.

Gastric bypass surgery, also called Roux-en-Y gastric bypass (RYGB), can result in the malabsorption of medications, requiring the use of higher than usual doses in order to achieve a therapeutic effect. We describe the results of hydroxychloroquine (HCQ) blood levels in three patients with systemic autoimmune disease taking standard HCQ doses and their associated disease activity levels. This is a retrospective review of all patients who had undergone RYGB and were taking HCQ in a rheumatology community-based practice.

ISCEV standard for clinical multifocal electroretinography (mfERG) (2011 edition).

The clinical multifocal electroretinogram (mfERG) is an electrophysiological test of local retinal function. With this technique, many local ERG responses are recorded quasi-simultaneously from the cone-driven retina under light-adapted conditions. This document, from the International Society for Clinical Electrophysiology of Vision (ISCEV: www.

Revised recommendations on screening for chloroquine and hydroxychloroquine retinopathy.

Background: The American Academy of Ophthalmology recommendations for screening of chloroquine (CQ) and hydroxychloroquine (HCQ) retinopathy were published in 2002, but improved screening tools and new knowledge about the prevalence of toxicity have appeared in the ensuing years. No treatment exists as yet for this disorder, so it is imperative that patients and their physicians be aware of the best practices for minimizing toxic damage.

Risk Of Toxicity: New data have shown that the risk of toxicity increases sharply toward 1% after 5 to 7 years of use, or a cumulative dose of 1000 g, of HCQ.

Using multifocal ERG ring ratios to detect and follow Plaquenil retinal toxicity: a review : Review of mfERG ring ratios in Plaquenil toxicity.

Multifocal ERG ring ratios provide a sensitive and objective method to detect ocular toxicity in patients taking hydroxychloroquine (Plaquenil). In order to measure ring ratios, the average mfERG amplitude was calculated for each of five concentric rings of a 61-hexagon mfERG. The age-corrected amplitude of the central hexagon (R(1)) and the ratios of R(1) to each of the successive rings (R(1)/R(2), R(1)/R(3), etc.

ISCEV guidelines for clinical multifocal electroretinography (2007 edition).

The clinical multifocal electroretinogram (mfERG) is an electrophysiological test of local retinal function. With this technique, many local ERG responses, typically 61 or 103, are recorded from the cone-driven retina under light-adapted conditions. This document specifies guidelines for performance of the test.

Detection of early hydroxychloroquine retinal toxicity enhanced by ring ratio analysis of multifocal electroretinography.

Purpose: To assess decreased retinal function associated with high cumulative doses of hydroxychloroquine using multifocal electroretinography (mfERG).

Design: Retrospective cross-sectional study.

Methods: Sixty-two patients referred for evaluation of hydroxychloroquine retinal toxicity.

Non-familial occult macular dystrophy.

Purpose: To present a series of patients who have poor central vision with normal funduscopic examination, fluorescein angiograms, and full field electroretinograms but significantly reduced multifocal electroretinographic responses most of whom are unaware of a family member similarly affected.

Methods: Patients were evaluated clinically and with the use of visual field testing, fluorescein angiography, full field electroretinography, VERIS Multifocal Electroretinographic testing (MFERG), which along with focal electroretinography is currently the only objective method of detecting these localized retinal dysfunctions, and Optical Coherence Tomography (OCT) where possible.

Results: Nine patients (18 eyes) referred for evaluation of undiagnosed poor central vision were found to have abnormal multifocal ERG findings affecting all or part of the central portion of the test field.