The present study reports data on 11 cases of hydroxychloroquine retinopathy that were monitored for 13 to 51 months after cessation of the drug. These cases are identical, with those studied previously with clinical data,
5 although several now have a longer period of follow-up. The demographics of these patients, history of drug exposure, and follow-up period are shown in the
Table. Because these cases were recognized up to 5 years previously, before new demographic data
1 showed the value of dose estimation by actual weight, the data are presented relative to ideal weight (which was measured at the time of diagnosis). Cases were categorized as early, moderate, or severe toxicity as described in previous reports,
3,5 by assessing the damage present when first diagnosed with HCQ retinopathy, using a variety of screening tests (Swedish Interactive Threshold Algorithm 10-2 visual fields, SD-OCT, fundus autofluorescence, and multifocal electroretinography). To summarize:
early is defined as patchy ellipsoid zone damage in the parafoveal region (i.e., areas of damage with parafoveal localization, but not coalesced into a clear ring);
moderate is defined as a clear ring (50% to 100% complete) of damage, but still without RPE involvement observed by SD-OCT, funduscopy, and/or autofluorescence; and
severe is defined as having RPE damage (by any of the assessment techniques) in the parafoveal bull's-eye region. This patient cohort was identified before it was recognized that Asian patients may show a more peripheral pattern of retinopathy
2; all were non-Asian except for two patients with severe cases (S1 and S4) who were Filipino and had parafoveal maculopathy as well as thinning throughout the macula.